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MCAT biology
MCAT biology
590
Biology
Undergraduate 3
05/04/2012

Additional Biology Flashcards

 


 

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Term
___ is the solvent in which the chemical reactions of living cells take place
Definition
water
Term
Water is a ___ that can ____
Definition
small polar molecule; hydrogen bond
Term
the ability of water to hydrogen bond allows it to ___ and also provides ____.
Definition
maintain its liquid state in the cellular environment; strong cohesive forces between water molecules
Term
These cohesive forces squeeze _____ away from water
Definition
hydrophobic molecules
Term
____ dissolve in water easily because ___
Definition
hydrophilic; their negatively charged ends attract the the H+ and their positively charged ends attract O-
Term
Thus water molecules ____ a hydrophilic molecule, thus seperating it from the group
Definition
surround (solvate)
Term
Most macromolecules of living cells are broken apart via ____, and are formed via ____
Definition
hydrolysis; dehydration synthesis
Term
a lipid is any molecule that has ___
Definition
low solubility in water and high solubility in nonpolar environments.
Term
lipids make excellent _____
Definition
barriers separating aqueous environments
Term
six major groups of lipids
Definition
fatty acids, triglycerides, phospholipids, glycolipids, steroids, and terpenes
Term
___ are the building blocks for most complex lipids
Definition
fatty acids
Term
fatty acids are long chains of ___ that are truncated at one end by a ____
Definition
carbons; carboxylic acid
Term
saturated fatty acids possess only ___
Definition
single carbon-carbon bonds
Term
unsaturated fatty acids contain one or more ___.
Definition
carbon-carbon double bonds
Term
___ of fatty acids liberates large amounts of chemical energy for a cell
Definition
oxidation
Term
most fats reach the cell in the form of ____
Definition
fatty acids, not triacylglycerols
Term
triglycerides , or simply ___, are constructed from ____, which is attached to ____
Definition
fats and oils; a three carbon backbone called glycerol; three fatty acids
Term
the function of triglycerides in a cell is to ____, and may also provide ___
Definition
store energy; thermal insulation and padding to an organism
Term
___, also called fat cells, are specialized cells whose cytoplasm contains almost nothing but triglycerides
Definition
adipocytes
Term
phospholipids are built from a ___ backbone, but a ____. This makes the phospholipid ____
Definition
glycerol backbone; polar phosphate group replaces one of the fatty acids; polar at the phosphate end and nonpolar at the fatty acid end
Term
The condition of being polar at one end and non-polar at the other is called ___
Definition
amphipathic
Term
phospholipids are the major component of ____
Definition
membranes
Term
glycolipids are similar to ____, except that glycolipids have ____. glycolipids are also ___. They are found in abundance in the ______
Definition
phospholipids; one or more carbohydrates attached to a three carbon glycerol backbone instead of the phosphate group; amphipathic; membranes of myelinated cells composing the human nervous system
Term
steroids are ____ structures that include ___,___, and ____
Definition
four ringed structures; hormones, vitamin D, cholesterol
Term
terpenes are a sixth class of lipids which include ____, a vitamin important for vision
Definition
vitamin A
Term
since lipids are insoluble in aqueous solution, they are transported in the blood via ___
Definition
lipoproteins
Term
a lipoprotein contains a lipid core surrounded by ___ and ___
Definition
phospholipids and apoproteins
Term
functions:
1. phospholipids:
2. triacylglycerols
3. steroids:
Definition
1. serve as a structural component of membranes
2. store metabolic energy, provide thermal insulation and padding
3. regulated metabolic activity
Term
proteins are built from a chain of ___ linked together by ___
Definition
amino acids; peptide bonds
Term
nearly all proteins are built from ____
Definition
the same 20 alpha amino acids
Term
in humans, 10 of the amino acids are ___; this means ____
Definition
essential; the body can't manufacture these so they must be ingested
Term
the amino acids often differ from each other only in their ____
Definition
side chains (R groups)
Term
the side chain is also attached to the ____
Definition
alpha carbon
Term
proteins are sometimes referred to as ____
Definition
polypeptides
Term
the number and sequence of amino acids in a polypeptide is called the ____
Definition
primary structure
Term
once the primary structure is formed, the single chain can ____ or ____
Definition
twist into an alpha helix, or lie along side itself and form a beta pleated sheet
Term
with beta pleated sheets, the connecting segments of the two strands of the sheet can lie ___ or ___
Definition
in the same direction (parallel) or in opposite directions (antiparallel)
Term
the alpha helix and beta pleated sheets are the ___, and contribute to the ____
Definition
secondary structure; conformation of the protein
Term
all proteins have a ___ structure and most have a ___ structure. Larger proteins can have a _____
Definition
primary; secondary; tertiary; quaternary
Term
the tertiary structure refers to the ___ formed when the ____
Definition
3-d structure; peptide chain curls and folds
Term
five forces that create the tertiary structure:
Definition
1. covalent disulfide bonds between two cysteine amino acids on different parts of the chain.
2. electrostatic interactions between acidic and basic side chains
3. hydrogen bonds
4. van der walls forces
5. hydrophobic side chains pushed towards center by water
Term
the quaternary structure is formed when ___
Definition
two or more polypeptide chains bind together
Term
when the conformation is disrupted, the protein is said to be ___
Definition
denatured
Term
carbohydrates are made from ___ and ___, and have the empirical formula ____
Definition
carbon and water, C(H2O)
Term
The six carbon carbohydrate ___ is the most commonly occuring six carbon carbohydrate
Definition
glucose
Term
anabolism
Definition
constructs bigger molecules from smaller molecules, dehydration synthesis, endergonic (absorbing energy in the form of work), not spontanteous
Term
catabolism
Definition
breaks down bigger molecules into small units, hydrolysis,exothermic
Term
essentially all digested carbohydrates have been converted to ___ by the ___
Definition
glucose, liver, enterocytes
Term
if a cell has sufficient ATP, glucose is ___,___, or ____
Definition
polymerized to the polysaccharide, glycogen, or converted to fat
Term
large amounts of glycogen are found in _____
Definition
muscle and liver cells
Term
nucleotides are composed of three components:
Definition
1. a five carbon sugar
2. a nitrogenous base
3. a phosphate group
Term
what are the nitrogenous bases
Definition
adenine, guanine, cytosine, thymine, and uracil
Term
nucleotides join polymers to create ___
Definition
nucleic acids, DNA, and RNA
Term
in nucleic acids, nucleotides are joined together by ____
Definition
phosphodiester bonds between the phosphate group of one nucleotide and the 3rd carbon of the pentose of the other nucleotide forming long strands
Term
in typical DNA, two strands are joined by ___ to make a structure called a ____
Definition
hydrogen bonds, double helix
Term
Adenine and thymine form _____
Definition
two hydrogen bonds
Term
guanine and cytosine form ___
Definition
three hydrogen bonds
Term
In typical RNA, there is _____
Definition
only one strand, no helix is formed, and uracil replaces thymine
Term
minerals are ____; they assist in the ____; they can _____; minerals also act as ____ assisting ____; example ____
Definition
dissolved inorganic ions inside and outside the cell; transport of substances entering and exiting the cell; combine and solidify to give strength to a matrix; cofactors, assisting protein or enzyme function; iron in the heme group
Term
4 other important nucleotides
Definition
ATP, cyclic AMP, NADH, FADH2
Term
the source of readily available energy for the cell
Definition
ATP
Term
a important component in many second messenger systems
Definition
cyclic AMP
Term
coenzymes involved in the krebs cycle
Definition
NADH, FADH2
Term
Virtually all biological reactions are governed by ____.
- few ___ act as ____
-enzymes are typically ___ proteins
- the function of any enzyme is to ____
_ enyzmes are not ___, and to not alter the ___ of the reaction
Definition
enzymes
- nucleic acids; enzymes
- globular
- act as a catalyst, lowering the energy of activation for a biological reaction and increasing the rate of that reaction
- consumed, equilibrium
Term
the substrate is the ____
- the position on the enzyme to where the substrate binds, usually with ____, is called the ____
Definition
reactant or reactants upon which an enzyme works.
-noncovalent bonds, active site
Term
the enzyme bound to a substrate is called the ____
- the ___ binds to the ___
Definition
enzyme-substrate complex
- substrate, enzymes active site
Term
normally, enzymes are designed to work on ___, this is called ____
Definition
only a specific substrate or group of closely related substances, enzyme specificity
Term
enzymes exhibit saturation kinetics, explain
Definition
as the rate of the substrate increases, the reaction rate increases. However, once the max reaction rate is achieved (ie all enzymes are being used), the rate cant increases further.
Term
how do temp and pH affect enzymatic reactions.
Definition
rate increases as temp and pH increases, however once temp and pH go past a certain point the proteins and enzymes start to denature and reaction rate decreases
Term
in order to reach their optimal activity, many enzymes require a non-protein component called a ____
- they can be ___ or ___
Definition
co-factor
- coenzymes or metal ions
Term
many coenzymes are ___
- an enzyme with its cofactor is called a ___
Definition
vitamins or their derivatives
- holoenzyme
Term
agents which bind covalently, sometimes noncovalently, to enzymes and disrupt their function are ___
Definition
irreversible inhibitors
Term
1.competitive inhibitors:___
2. noncompetitive inhibitors:___
Definition
1.compete with the substrate by binding reversibly with noncovalent bonds to the active site.
2. bind noncovalently to an enzyme at a spot other than the active site and change the conformation of the active site.
Term
many enzymes are released into their environment in an inactive form called a ___ or ___
Definition
zymogen or proenzyme
Term
allosteric interactions: ___
Definition
allosteric regulation is the modification of the enzyme configuration resulting from the binding of an activator or inhibitor as a specific binding site on the enzyme
Term
normally an enzyme governs ____
- if one of the products downstream in a reaction series comes back and inhibits the enzymatic activity in an early reaction, this is known as ___
-___ happens when the product returns to active the enzyme
Definition
just one reaction in a series of reactions
- negative feedback or feedback inhibition
-positive feedback
Term
feedback inhibitors do not ____, instead they ____, this is called ____
Definition
resemble the substrates of the enzymes that they inhibit; they bind to the enzyme and cause a conformational change; allosteric regulation (not necessarily noncompetitive inhibitors)
Term
___: all cellular chemical reactions
___: molecular synthesis
___: molecular degradation
Definition
metabolism
anabolism
catabolism
Term
if ___ is used, respiration is ___, if it is not used the respiration is ___
Definition
oxygen, aerobic, anaerobic
Term
___: is respiration in which oxygen is not required
Definition
anaerobic respiration
Term
glycolysis is the ___ of ___
Definition
first stage of anaerobic and aerobic respiration
Term
glycolysis is the series of reactions that ____
Definition
breaks a 6 carbon glucose molecule into two 3 carbon molecules of pyruvate
Term
____ are capable of breaking down glucose to pyruvate
Definition
all living cells and organisms
Term
Does glycolysis require oxygen?
Where does glycolysis occure?
Definition
glycolysis will operate in both the presence and absence of oxygen; the reactions of glycolysis occur in the cytosol of living cells
Term
substrate level phosphorylation is the ____
Definition
formation of ATP from ADP and inorganic phosphate using the energy released from the decay of high energy phosphorylated compounds as opposed to using the energy from diffusion
Term
The products of carbohydrate digestion in the alimentary tract are approximately ____
Definition
80% glucsoe and 20% fructose which are both monosaccharides
Term
fermentation is a form of ____
-it includes the process of ____
--yeast and some microorganisms make ___
-- human muscle cells and some microorganisms produce ___
Definition
anaerobic respiration
- glycolysis, the reproduction of pyruvate to ethanol or lactic acid, and the oxidation of NADH back to NAD+
--ethanol
--lactic acid
Term
fermentation takes place when ___
In fermentation, the NAD+ is ___
Definition
a cell or organism is either unable to assimilate the energy from NADH and pyruvate, or has no oxygen available to do so; is restored for use in its role in glycolysis as a coenzyme, and the lactic acid or ethanol is expelled from the cell along with carbon dioxide as a waste product
Term
glycolysis has a net production of ____
Definition
2 ATP
Term
What will happen when a certain enzyme is inhibited by a poison?
Definition
The poison will create a build up of reactants and a dramatic reduction of products at the reaction that the enzyme governs.
Term
fermentation recycles ____
Definition
NADH back to NAD+
Term
aerobic respiration requires ___
- the products of glycolysis move into the ____
- once inside, the pyruvate is converted to ___ in a reaction that produces ___ and ___
Definition
oxygen
- matrix of mitochondrion
- acetyl CoA, CO2, NADH
Term
___ is a coenzyme which transfers two carbons to the ___ to begin the ___
Definition
Acetyl CoA; 4 carbon oxaloacetic acid; Krebs cycle
Term
Each turn of the Krebs cycle produces __
- The process of ATP formation in the Krebs cycle is by ___
Definition
1 ATP, 3 NADH, 1 FADH2
- substrate level phosphorylation
Term
The electron transport chain is a ____
Definition
series of proteins, including cytochromes with heme, located in the inner membrane of the mitochondrion
Term
The electron transport chain creates ATP through ___
Definition
oxidative phosphorylation
Term
aerobic respiration produces about ____ ATP
Definition
36 net
Term
a gene is a ___ that generally codes ___
Definition
series of DNA nucleotides; for the production of a single polypeptide or mRNA, rRNA, or tRNA.
Term
generally one gene = ____
- exception is ___
Definition
one polypeptide
- postrancscipional processing RNA
Term
how do eukaryotes and prokaryotes differ in genes
Definition
eukaryotes have more than one copy of some genes, while prokaryotes have only one copy of each gene
Term
genes are often referred to as ___
-while regions of non-coding DNA found only in eukaryotes are called ____
-eukaryotic genes that are being actively transcribed by a cell are associated with regions of DNA called __
-while genes not being actively transcribed are associated with tightly packed regions of DNA called ___
Definition
unique sequence DNA
-repetitive sequence DNA
-euchromatin
-heterochromatin
Term
even in eukaryotes, ___ dominated
- ___ is found mainly in heterochromatin
Definition
unique sequence DNA
-repetitive sequence DNA
Term
the entire DNA sequence of an organism is called the ___
Definition
genome
Term
what is the central dogma?
Definition
DNA to RNA to protein
Term
___ is a polymer of nucleotides
-They differ from each other only in their ___
Definition
DNA
- nitrogenous bases
Term
the four nitrogenous bases are
Definition
adenine, guanine, cytosine, thymine
Term
adenine and guanine are ____
Definition
two ringed structures called purines
Term
cytosine and thymine are ___
Definition
single ring structures called pyrimidines
Term
each nucleotide is bound to the next by a ___
- this creates the
Definition
phosphodiester bond between the third carbon of one deoxyribose and the fifth carbon of the other
- 5 prime to 3 prime directionality
Term
the end 3 prime carbon is attached to ___; and the end 5 prime carbon is attached to a ___
Definition
an oh group; phosphate group
Term
purines:
pyrimidines:
hydrogen bonds:
Definition
adenine, guanine
cytosine, thymine, uracil
A2T, C3G
Term
the two DNA strands lie ____
Definition
side by side in opposite 3 to 5 directions, anti-parallel, connected by hydrogen bonds
Term
two strands that have the bases match up correctly are called ___, and curl into a ___
Definition
complimentary strands; double helix
Term
DNA replication is said to be ___ because ___
Definition
semi-conservative; because the new strand contains one parental strand and one daughter strand
Term
The process of DNA replication is governed by a group of proteins called a ___.
- where does replication begin?
Definition
replisome
-replication does not begin as the end of a chromosome, but toward the middle as a site called the origin of replication
Term
a single eukaryotic chromosome contains ___ on each chromosome, while replication in prokaryotes usually takes place ___
Definition
multiple origins of replication; for a single origin on the circular chromosome
Term
from the origin, ____
- the point where the replisome is attached to the chromosome is called the ___
- each chromosome of eukaryotic DNA is replicated in many discrete segments called _____
Definition
two replisomes proceed in opposite directions along the chromosome making replication a bidirectional process.
-replication fork
-replication units or replicons
Term
___: unwinds the double helix separating the two strands
Definition
DNA helicase
Term
DNA polymerase
Definition
the enzyme that builds the new DNA strand, cannot initiate a strand from two nucleotides, but can only add nucleotides to an existing strand
Term
primase:___
- what happens after primase?
Definition
an RNA polymerase, creates an RNA primer approximately 10 ribonucleotides long to initiate the strand
- DNA polymerase adds deoxynucleotides to the primer and moves along each DNA strand creating a new complimentary strand
Term
DNA polymerase reads the parental strand in the ___ direction, creating the new complimentary strand in the ___ direction
Definition
3 to 5; 5 to 3
Term
each nucleotide added to the new strand requires the removal of a ____ from a ___
Definition
pyrophosphate group (two phosphates bonded together); deoxynucleotide triphosphate
Term
replication proceeds in ____, each section produces a ____
Definition
both directions from the origin; leading and lagging strand
Term
the leading and lagging strands are produced in the ___ direction
Definition
5 to 3
Term
DNA polymerase reads the parental strand in the ___ direction and creates the daughter strand in the ___ direction
Definition
3 to 5; 5 to 3
Term
The polymerization of the new strand that is continuously interrupted and restarted with a new primer, the strand is called the ____ and made from a series of disconnected strands called ____; the continuous new strand is called the ____
Definition
lagging strand; okazaki fragments; leading strand
Term
____ moves along the lagging strand and ties the okazaki fragments together to complete the polymer. since the formation of one strand is continuous and the other fragmented, the process of replication is said to be ___
Definition
DNA ligase; semidiscontinuous
Term
How accurate is DNA replication in eukaryotes?
Definition
very accurate; exonuclease in DNA polymerase proofreads the new strands
Term
The ends of eukaryotic chromosomal DNA possess ____, which are repeated six nucleotide units that protect the chromosomes from being eroded through repeated rounds of replication.
Definition
telomeres
Term
5 steps of replication
Definition
1. helicase unzips the double helix
2. RNA polymerase builds a primer
3. DNA polymerase assembles the leading and lagging strands
4. the primers are removed
5. okazaki fragments are joined
Term
DNA replication is ___ and ___
Definition
fast and accurate
Term
list the differences between DNA and RNA
Definition
1. DNA is made from deoxyribose and RNA is made from ribose
2. DNA is double stranded and RNA is single stranded
3. DNA has thymine, RNA has uracil
4. DNA is produced by replication and RNA is produced by transcription
5. in animals, DNA is only in the nucleus and mitochondrial matrix; RNA is also in the cytosol
6. there is one major type of DNA; there are three major types of RNA
Term
unlike DNA, RNA can move ___
Definition
through the nuclear pores and is not confined to the nucleus
Term
what are the three types of RNA
Definition
mRNA, tRNA, rRNA
Term
___ delivers the DNA code for amino acids to the ___ where proteins are manufactured
Definition
mRNA; cytosol
Term
___ combines with proteins to form ___, and ___ is synthesized in the ___
Definition
rRNA; ribosomes; rRNA; nucleolus
Term
___ collects amino acids in the cytosol, and transfers them to the ribosomes for incorporation into a protein
Definition
tRNA
Term
___ are the cellular complexes that direct the synthesis of proteins
Definition
ribosomes
Term
all RNA is manufactured from a ___ in a process called ___
Definition
DNA template; transcription
Term
since DNA ____, eukaryotic transcription must take place only in these two places
Definition
cannot leave the nucleus or the mitochondrial matrix
Term
the beginning of transcription is called ___; this happens when ___
Definition
initiation; a group of proteins called initiation factors find a promotor on the DNA strand, and assembles a transcription initiation complex which includes RNA polymerase
Term
prokaryotes have ___, whereas eukaryotes have ___
Definition
one type of RNA polymerase; 3 types, one for each type of RNA
Term
A promotor is a ____
Definition
sequence of DNA nucleotides that designates a beginning point for transcription
Term
transcription requires a ___, whereas replication requires a ___
Definition
promoter; primere
Term
a promoter ____; a primer ____
Definition
is a spot on the DNA that tells RNA polymerase where to begin; is a short piece of RNA that jump starts replication
Term
after binding to the promoter, _____
Definition
RNA polymerase unzips the DNA double helix and switches to elongation mode
Term
in elongation mode, ___
Definition
RNA polymerase transcribes only one strand of the DNA nucleotide sequence into a complimentary RNA nucleotide sequence
Term
how does RNA polymerase move?
Definition
reads the DNA in the 3 to 5 direction and builds the RNA strand in the 5 to 3 direction
Term
how does transcription proceed?
Definition
about ten times more slowly than DNA replication and RNA polymerase does not contain a proofreading mechanism so the rate or error is higher than replication
Term
the end of transcription is called ____, and requires a special ____
Definition
termination; termination sequence and special proteins to dissociate RNA polymerase from DNA.
Term
most genetic regulation occurs at ___ where ___
Definition
transcription; regulatory proteins bind DNA and activate or inhibit its transcription
Term
post transcriptional processing of RNA occurs in ____
Definition
both eukaryotic and prokaryotic cells
Term
in prokaryotes, ___ goes through post transcriptional processing. While in eukaryotes _____
Definition
rRNA and tRNA. each type of RNA undergoes posttranscriptional processing which allows for additional gene regulation
Term
The initial mRNA nucleotide sequence arrived at through transcription is called the ____
Definition
primary transcript
Term
The primary transcript is modified in three ways
Definition
1) addition of nucleotides 2) deletion of nucleotides 3) modification of nitrogenous bases
Term
before leaving the nucleus, the primary transcript is cleaved into ____
Definition
introns and exons
Term
The introns are ___ and the exons are ___
Definition
then excised by the splicesomes; spliced together to form the single mRNA code that ultimately codes for the polypeptide
Term
remember that introns ___ and exons ___
Definition
remain in the nucleus; exit the nucleus to be translated
Term
most of a typical gene consists of ____
Definition
introns removed by snRNP's in the nucleus
Term
to denature DNA means to ____
Definition
seperate the two strands of the double helix
Term
DNA prefers to be ____
Definition
double stranded and will look for a complimentary partner
Term
what following double stranded combinations can be formed through nucleic acid hybridization
Definition
DNA-DNA
DNA-RNA
RNA-RNA
Term
restiction enzymes ___
Definition
digest/cut nucleic acid only at certain nucleotide sequences along the chain
Term
typically a restriction site will be a ___
Definition
palindromic sequencee
Term
recombinant DNA can be made long enough for bacteria to replicate and then placed within the bacteria using a ___, typically a ___
Definition
vector; plasmid
Term
____ is just DNA reverse transcribed from mRNA
Definition
complimentary DNA
Term
___ is a fast way to clone DNA
Definition
PCR
Term
a ___ identifies specific sequences of DNA by nucleic acid hybridization, and a ___ uses the same techniques to identify specific sequences of RNA
Definition
southern blot; northern blot
Term
the 5 step recipe for southern blot is ___
Definition
1. chop up some DNA
2. use an electric field to spread out particles according to size
3. blot it onto a membrane
4. add a radioactive probe made from DNA or RNA
5. visualize with radiographic film
Term
the western blot is the one that detects a ___ with ___
Definition
protein; antibodies
Term
mRNA nucleotides are strung together to form a ___ which translates the DNA nucleotide sequence into an amino acid sequence
Definition
genetic code
Term
the fact that more than one series of three nucleotides may code for any amino acid, the code is ___
Definition
degenerative
Term
any single series of three nucleotides will code for one and only one amino acids, the code is ___
Definition
unambiguous
Term
what is the start codon and the stop codons
Definition
start:AUG
stop: UGA, UAA,UAG
Term
___ is the process of protein synthesis directed by mRNA
Definition
translation
Term
___ makes up the ribosome
___ contains the anti codons
___ is the template which carries the genetic code from the nucleus to the cytosol in the form of codons
Definition
rRNA
tRNA
mRNA
Term
the ribosome is composed of a ___ and a ___
Definition
small subunit and a large subunit
Term
the complex structure of ribosomes requires a special organelle called the ___ in which to manufacture them.
Definition
nucleolus
Term
___ do not possess a ___ but synthesis is similar
Definition
prokaryotes; nucleolus
Term
what are the processes of translation
Definition
1. initiation: start codon reached, small subunit joins large subunit
2. elongation: polypeptide formation begins
3. termination: stop codon reached
Term
in an elongation step called ___, codons are shifted
Definition
translocation
Term
in ___, sugars, lipids, or phosphate groups may be added to amino acids
Definition
post-translational modifications
Term
mutations are ___; mutations in ___ are not passed to offspring; mutations in ___ are.
Definition
rare; somatic cells; germ cells
Term
any alteration in the genome that is not genetic recombination is called a ____
Definition
mutation
Term
a ___ is the alteration in the sequence of DNA nucleotides in a single gene. A ___ occurs when the structure of the chromosome is changes
Definition
gene mutation; chromosomal mutation
Term
in animals, DNA is found only in the ___ and ___
Definition
DNA and mitochondria
Term
the sections of DNA that are not in uses are wrapped tightly around globular proteins called ___, eight histone wrapped in DNA form a ___. The entire DNA/protein complex is called ___
Definition
histone; nucleosome; chromatin
Term
how many chromosomes do humans have? in humans each chromosome possesses a partner that codes for the same trait, two such chromosomes are called ___. Any cell that contains homologous pairs is said to be ___, and any cell that does not contain homologues is ___
Definition
46 chromosomes; homologues; diploid; haploid
Term
what are the stages in the life cycle of a cell?
Definition
1. first growth phase (G1)
2. synthesis (S)
3. second growth phase (G2)
4. mitosis or meiosis (M) and Cytokinesis (C)
Term
___ is nuclear division without genetic change
Definition
mitosis
Term
what are the stages of mitosis
Definition
prophase, metaphase, anaphase, telophase
Term
in prophase ___
Definition
1. condensation of chromatin into chromosomes.
2.centrioles move to opposite ends of cells
3. spindle apparatus begins to form
Term
in metaphase ___
Definition
chromosomes align along the center of the cell
Term
in anaphase ___
Definition
1. sister chromatids split at their attaching centromeres.
2. chromatids move towards opposite ends of cells
3. cytokinesis, the separation of the cytoplasm
Term
in telophase ___
Definition
1. nuclear membrane reforms
2. followed by reformation of the nucleus
3. chromosomes decondens and cytokinesis continues
Term
mitosis results in ____
Definition
genetically identical daughter cells
Term
meiosis is a double nuclear division which produces ____. In humans, only ___ and the ___ undergo meiosis. all other cells are ___ and undergo ___ only
Definition
four haploid gametes (also called germ cells). spermatogonium, oogonium. somatic cells; mitosis
Term
how does meiosis divide
Definition
meiosis is two rounds of division called meiosis I and meiosis II
Term
in prophase I
Definition
homologous chromosomes line up along side each other, matching genes exactly. At this time crossing over may occur
Term
in metaphase I
Definition
the homologues remain attached, and move to the metaphase plate
Term
anaphase I ___
Definition
seperates the homologues from their partners
Term
in telophase I ___
Definition
in humans the nuclear membrane reforms and cytokinesis occurs, the new cells are haploid
Term
meiosis I is ___ division
Definition
reduction
Term
___ are infectious agents, much smaller than bacteria
Definition
viruses
Term
in its most basic form, a virus consists of a ___, called a ___, and one to several hundred genes ____
Definition
protein coat; capsid; in the form of DNA or RNA
Term
no virus contains ____
Definition
both DNA and RNA
Term
most animal viruses, some plant viruses, and very few bacterial viruses surround themselves with a ____
Definition
lipid rich envelope
Term
the envelope typically contains some ___
Definition
virus specific proteins
Term
a mature virus outside the host cell is called a ___. all organisms experience ___
Definition
virion; viral infections
Term
viruses are not ____. why?
Definition
currently classified as living organisms. they require the host cell's machinery to reproduce, viruses do not metabolize organic nutrients, instead they use ATP from the host cell
Term
the receptor on the host that a virus usually attaches to is usually a ____
Definition
specific glycoprotein on the host cell membrane, the virus cannot attack the cell if the specific receptor is not available.a
Term
___ is a virus that infects bacteria
Definition
bacteriophage
Term
most viruses that infect eukaryotes are engulfed by a ____ process
Definition
endocytotic
Term
explain what happens in a lytic infection?
Definition
the virus commandeers the cell's reproductive machinery and begins reproducting new viruses. There is a brief period before the first fully formed virion appears called the eclipse period. The cell may fill with new viruses until it lyses or bursts, or it may release the viruses one at a time.
Term
In a lytic infection, the period from infection to lysis is called the ____
Definition
latent period
Term
A virus following a lytic cycle is called a ____
Definition
virulent virus
Term
what happens in a lysogenic infection?
Definition
The viral DNA is incorporated into the host genome, or if the virus is an RNA virus and possesses the enzyme reverse transcriptase, DNA is actually reverse transcribed from RNA and then incorporated into the host cell genome. When the host cell replicates its DNA, the viral DNA is replicated as well.
Term
A virus in a lysogenic cycle is called a ____
Definition
temperate virus
Term
A host cell infected with a temperate virus may show ___. While the viral DNA remains incorporated into the host DNA, the virus is said to be ____
Definition
no symptoms of infection; dormant or latent, and is called a provirus (prophage in bacterium)
Term
The dormant virus may become active when ___
Definition
the host cell is under some type of stress
Term
a virus with ___ is responsible for the common cold, which means ____
Definition
unenveloped plus-strand RNA; not all animal viruses are enveloped
Term
a ___ can be either an injection of antibodies or an injection of a non-pathogenic virus with the same capsid or envelope
Definition
vaccine
Term
Prokaryotes do not have a ___ or ___
Definition
membrane bound nucleus; complex membrane bound organelles
Term
Prokaryotes are split into what two domains?
Definition
bacteriea and archea
Term
___ have as much in common with eukaryotes as they do with bacteria and are usually found in extreme environments
Definition
archaea
Term
most know prokaryotes are members of the domain ___
Definition
bacteria
Term
unlike bacteria, the cell walls of archea are not made from ___
Definition
peptidoglycan
Term
___ are organisms that are capable of using CO2 as their sole source of carbon
Definition
autotrophs
Term
___ is an organism that cannot synthesize its own food and is dependent on complex organic substances for nutrition
Definition
heterotrophs
Term
all organisms acquire energy from one of what two sources:
Definition
1. light
2. oxidation of organic or inorganic matter
Term
organisms that use light as their energy source are called ____; those that use oxidation of organic or inorganic matter are called ___
Definition
phototrophs; chemotrophs
Term
electrons or hydrogens can be acquired from inorganic matter by ___; or organic matter by ___
Definition
lithotrophs; organotrophs
Term
The structure that replaces the nucleus in prokaryotes is called the ____
Definition
nucleoid/chromatin body
Term
what are the major shapes of bacteria?
Definition
cocci=round
bacilli=rod shaped
spirilla=helically shaped rigid
Term
the cytosol of nearly all prokaryotes is surrounded by a phospholipid bilayer called the ____
Definition
plasma membrane
Term
The phospholipid bilayer is often composed of ____
Definition
a phosphate group, two fatty acid chains, and a glycerol backbone
Term
The phosphate group is ___, while the fatty acid chains are ___, making the molecule ___
Definition
polar; nonpolar; amphipathic
Term
when placed in an aqueous solution, amphipathic molecules ____
Definition
spontaneously aggregate, turning their polar ends toward the solution and their nonpolar ends toward each other.
Term
___ are also embedded within the plasma membrane and act as ___
Definition
proteins; transporters, receptors, attachment sites, and enzymes
Term
amphipathic proteins that transverse the membrane from the inside of the cell to the outside are called ___. ___ are situated entirely on the surface of the membrane
Definition
intrinsic or integral proteins; peripheral or extrinsic proteins
Term
integral or extrinsic proteins may contain carbohydrate chains making them ___
Definition
glycoproteins
Term
the model of the plasma membrane is known as the ____
Definition
fluid mosaic model
Term
all molecules move rapidly in random directions frequently colliding with one another, this random movement is called ___
Definition
brownian motion
Term
What are the two aspects of a compound that affect its semipermeability?
Definition
size and polarity
Term
When proteins assist molecules in moving through the membrane because they are to large or to polar, these proteins are called ___
Definition
transport or carrier proteins
Term
the type of movement that involves transport proteins is called ___
Definition
facilitated diffusion
Term
facilitated diffusion is said to make the plasma membrane ____
Definition
selectively permeable
Term
movement of a substance against its electrochemical gradient requires ____
Definition
active transport
Term
The bacterial plasma membrane and everything inside it is called the ___
Definition
protoplast
Term
a protoplast is not ____
Definition
a complete bacterium
Term
surrounding the protoplast is the ____
Definition
bacterial envelope
Term
the component of the envelope, adjacent to the plasma membrane is the ___
Definition
cell wall
Term
most bacteria are ___ to their environment
Definition
hypertonic
Term
____= more particles in bacteria cytosol than fluid surrounding them
___= cytosol equals amount of particles
___= cytosol contains less particles
Definition
hypertonic, isotonic, hypotonic
Term
the bacterial cell wall is made of ____
Definition
peptidoglycan
Term
a gram positive bacteria ____
Definition
stains purple, thick peptidoglycan cell wall
Term
a gram negative bacteria
Definition
stains pink, have a thin peptidoglycan cell wall
Term
bacterial ___ are long, hollow, rigid, helical cylinders made from a globular protein called ____
Definition
flagella; flagellin
Term
eukaryotic flagella are composed of ___
Definition
microtubules
Term
bacteria do not undergo ___, and cannot ____
Definition
mitosis or meiosis; reproduce sexually
Term
3 alternative forms of bacterial genetic recombination
Definition
conjugation, transformation, transduction
Term
bacteria are also capable of undergoing a type of cell division called ___, which is a type of asexual reproduction
Definition
binary fission
Term
binary fission produces
Definition
two genetically identical daughter cells with one circular chromosome in each daugher cell
Term
conjugation requires
Definition
one of the bacterium have a plasmid with the gene that codes for the sex pilus. The bacteria with the F plasmid (fertility factor) is the F+, and the one without is the F-.
Term
Transformation is the process by which ___
Definition
bacteria may incorporate DNA from their external environment into their genome
Term
transduction is the process by which ___
Definition
DNA is transferred by one bacterium to another by a virus
Term
fungi are ___, and spend most of their time in a ___, and can reproduce ___
Definition
eukaryotic heterotrophs; haploid state; either sexually or asexually
Term
The major feature distinguishing eukaryotic cells from prokaryotic cells is the ___
Definition
nucleus of the eukaryote
Term
only ___ have nuclei. ___ cannot leave the cell, therefore ___ must take place in the nucleus. ___ leaves the nucleus through nuclear pores
Definition
eukaryotes; DNA; transcription; RNA
Term
the aqueous soup inside the nucleous is called the ___. The nucleus is wrapped in a ___
Definition
nucleoplasm; double phospholipid bilayer called the nuclear envelope/membrane
Term
The nuclear envelope is perforated with large holes called ___. Within the nucleus is an area called the ___ where rRNA is transcribed and the subunits of the ribosomes are assembled
Definition
nuclear pores; nucleolus
Term
besides transport across the membrane, cells can aquire substances from the extracellular environment through ___
Definition
endocytosis
Term
two types of endocytosis
Definition
phagocytosis and pinocytosis
Term
in phagocytosis the cell ___, while in pinocytosis the cell ___
Definition
takes up solid substances; take up liquid
Term
___ is simply a reverse of endocytosis
Definition
exocytosis
Term
the eukaryotic cell contains a thick maze of membranous walls called the ___ separating the ___ from the ___
Definition
ER; cytosol from the ER lumen/cisternal space
Term
ER near the nucleus that has many ribosomes attached to it is the ____
Definition
granular or rough ER
Term
proteins synthesized on the rough ER are pushed into the ___ and sent to the ___
Definition
ER lumen; golgi
Term
the cell can be divided into the ____ and ___
Definition
cytosol and ER lumen
Term
in order to reach the cytosol, a substance must cross the membrane by ___, but it can reach the ER lumen via ___ without ever transporting across the membrane
Definition
passive or facilitated diffusion or active transport; endocytosis
Term
The golgi ____
Definition
modifies and packages proteins for use in other part of the cell and outside the cell
Term
lysosome contain ____. lysosomes come from the ___
Definition
hydrolytic enzymes that digest substances taken in by endocytosis. come from the golgi
Term
endoplasmic reticulum which lacks ribosomes is called the ____
Definition
agranular or smooth ER
Term
The smooth ER is the site of ____
Definition
lipid synthesis including steroids. The smooth ER also helps to detoxify some things.
Term
The structure and motility of a cell is determined by a network of filaments known as the ____
Definition
cytoskeleton
Term
two major types of filaments in the cytoskeleton are ___ and ___
Definition
microfilaments and microtrubules
Term
microtubules are ___ than microfilaments. They are ____ made from a protein called ___
Definition
larger; rigid hollow tubes; tubulin
Term
The ___ is made from microtubules
Definition
mitotic spindle
Term
___ and ___ are specialized structures also made from microtubules.
Definition
flagella; cilia
Term
The major portion of each flagellum and cilium is called the ___, and contains nine pair of microtubules forming a circle around two lone microtubules in an arrangement known as ___
Definition
axoneme; 9+2
Term
The major microtubule organizing center in animal cells is the ____
Definition
centrosome
Term
eukaryotic flagella are made from a ___ microtubule configuration. a prokaryotic flagellum is a ___. Eukaryotic flagella undergo a ___ action, while prokaryotic flagella ___
Definition
9+2; thin strand of a single protein called a flagellin; whip like action; rotate
Term
microfilaments are ___ than microtubules. The protein ___ forms a major component of microfilaments.
Definition
smaller; actin
Term
___ form a watertight seal from cell to cell that can block water, ions, and other molecules from moving around and past cells
Definition
tight junctions
Term
___ join two cells at a single point
Definition
desmosomes
Term
___ are small tunnels connecting cells, that allow small molecules and ions to move between cells
Definition
gap junctions
Term
remember the three types of cellular junctions. ___ act as a fluid barrier around cells. ___ are like spot welds holding cells together. ___ are tunnels between cells allowing for the exchange of small molecules
Definition
tight junctions; desmosomes; gap junctions
Term
___ are the powerhouses of the eukaryotic cell
Definition
mitochondria
Term
According to the ___, mitochondria may have evolved from a symbiotic relationship between ancient prokaryotes and eukaryotes
Definition
endosymbiont theory
Term
mitochondria are surrounded by ___
Definition
two phospholipid bilayers
Term
The ___ of the mitochondria invaginates to form ___. it also holds the ___
Definition
inner membrane; cristae; electron transport chain
Term
between the inner and outer membrane of the mitochondria, there is the ___
Definition
intermembrane space
Term
what are the four basic tissue types in animals
Definition
nervous, muscle, epithelial, connective
Term
Three classes of molecules that make up animal cell matrices
Definition
1. glycosaminoglycans and proteoglycans
2. structural proteins
3. adhesive proteins
Term
intercellular communication is accomplished chemically via what three types of molecules
Definition
1. neurotransmitters
2. local mediators
3. hormones
Term
___ travel over very short intercellular gaps; ___ function in the immediate area around the cell from which they were released; ___ travel throughout the organism via the blood stream.
Definition
neurotransmitters; local mediators; hormones
Term
neurotransmitters are released by ___. neuronal communication tends to be __,___, and ___
Definition
neurons; rapid, direct, specific
Term
hormonal communication tends to be ___, ___, ___
Definition
slower, spread throughout the body, and affect many cells and tissues in many different ways.
Term
local mediators are released by a variety of cells into the ___
Definition
interstitial fluid
Term
The functional unit of the nervous system is the ____
Definition
neuron
Term
The ___ of the neuron receive a signal to be transmitted
Definition
dendrites
Term
typically the ___ of the cell body is highly conductive and any electrical stimulus creates a disturbance in the electric field that is transferred immediately to the ___
Definition
cystol; axon hillock
Term
The ___ generates an action potential in all directions, including down the ___
Definition
axon hillock; axon
Term
in a neuron the signal travels from the ___ to the ___, where an ap is generated, and moves down the ___ to the ___
Definition
dendrites; axon hillock; axon; synapse
Term
neurons do not depend on ___ to obtain glucose
Definition
insulin
Term
The ___ is a disturbance in the electric field across the membrane of a neuron
Definition
action potential
Term
the resting potential is established by equilibrium between ___ and ___
Definition
passive diffusion of ions across the membrane and the Na/K pump
Term
the Na+/K+ pump, pumps ____
Definition
3 Na out for every 2 K in
Term
what happens during depolarization
Definition
stimulus depolarizes the membrane by acting on chemically gated sodium channels, resulting in Na moving into the cell making the cell more +
Term
what happens during repolarization?
Definition
voltage gated sodium channels close; voltage gated potassium channels open and leads to repolarization
Term
what happens during hyperpolarization?
Definition
potassium channels are slow to close, so for a brief time the inside membrane is even more negative than resting potential
Term
___ returns the membrane to its resting potential
Definition
passive diffusion
Term
at rest the inside of the cell is ___ than the outside
Definition
more negative
Term
an action potential is ____
Definition
all or nothing
Term
the stimulus to the membrane must be greater than the ____
Definition
threshold stimulus
Term
once an action potential has begun, there is a short period of time called the ___ in which no stimulus will create another action potential. The ___ gives the time during which only an abnormally large stimulus will create an action potential
Definition
absolute refractory period; relative refractory period
Term
neural impulses are transmitted from one cell to another chemically or electronically via a ____
Definition
synapse
Term
___ are uncommon, they are composed of ____
Definition
electrical synapses; gap junctions betweeen cells
Term
___,___, ____ contain electrical synapses
Definition
cardiac muscle, visceral smooth muscle, and a very few neurons in the central nervous system
Term
since they don't involve diffusion of chemicals, electrical synapses are ___ than chemical synapses
Definition
much faster
Term
3 possible neuronal structures
Definition
unipolar, bipolar, multi polar
Term
unipolar:
bipolar:
multipolar:
Definition
unipolar: sensory only
bipolar: retina, inner ear, olfactory area of the brain
multipolar: most neurons of the brain
Term
chemical synapses are ____
Definition
unidirectional
Term
the sudden influx of calcium ions causes some of the neurotransmitter vesicles to be released through an exocytotic process into the ____
Definition
synaptic cleft
Term
receptors may be ion channels themselves, which are opened when their respective neurotransmitter attaches, or they may act via a ____
Definition
second messenger system
Term
besides neurons, nervous tissue contains may support cells called ____
Definition
glial cells or neuroglia
Term
only vertebrates have ____
Definition
myelinated axons
Term
in the peripheral nervous system, myelin is produced by ____
Definition
schwann cells
Term
myelin increases the rate at which ____
Definition
an axon can transmit signals
Term
to the naked eye, myelinated cells appear ___, while neuronal cells appear ____
Definition
white; gray
Term
the gaps between myelin are called ___.
Definition
nodes of ranvier
Term
the movement of the ap from one node of ranvier to the next is called ___
Definition
saltatory conduction
Term
___ receives signals from a receptor cell, and transmits this info to the brain
Definition
sensory (afferent neurons)
Term
___ transfers signals from neuron to neuron
Definition
interneurons
Term
____ carries signals to muscles or glands
Definition
motor (efferent) neurons
Term
neuron processes are typically bundled together to form ____
Definition
nerves (called tracts in the CNS)
Term
The central nervous system consists of ___
Definition
the brain and spinal cord, lots of interneurons
Term
The Peripheral nervous system heads the ___ and ___ functions of the nervous system. can be divided into the ___ or ___.
Definition
sensory and motor functions; somatic and autonomic
Term
the somatic system can be divided into:
The autonomic can be divided into:
Definition
sensory and motor; sympathetic and parasympathetic
Term
acetylcholine is used by:
Definition
all preganglionic neurons in the ANS and postganglionic neurons in the parasympathetic.
Term
epi and norepi are used by:
Definition
the postganglionic neurons of the sympathetic nervous system
Term
the receptors for epi and norepi are called ____. the receptors for ach are called ___
Definition
adrenergic; cholinergic
Term
the lower brain consists of the:
Definition
medulla, pons, mesencephalon, hypothalamus, thalamus, cerebellum, and basal ganglia
Term
the higher brain consists of the:
Definition
cerebrum or cerebral cortex
Term
5 types of sensory receptors
Definition
mechanoreceptors for touch
thermoreceptors for temp change
nociceptors for pain
electromagnetic receptors for light
chemoreceptors for taste, smell, and blood chemistry
Term
The lens of the eye is a ___
Definition
converging lens.
Term
what three small bones are in the middle ear
Definition
malleus, incus, stapes
Term
in the ear, the ___ detects sound, while the ___ detects orientation and movement of the head
Definition
cochlea; semicircular canals
Term
what are the four primary taste sensations
Definition
bitter, sour, salty, sweet
Term
The difference between endocrine and exocrine glands is that ____
Definition
endocrine glands release hormones directly into body fluids. Exocrine glands release enzymes to the external environment through ducts
Term
exocrine glands include ____
Definition
sweat, sebaceous, mucous, and digestive
Term
The ___ acts as both an endocrine and exocrine gland
Definition
pancreas
Term
The effects of the endocrine system tend to be ____
Definition
slower, less direct, and longer lasting
Term
all hormones act by ___
Definition
binding to proteins called receptors
Term
hormones exist in three basic types
Definition
peptide hormones, steroid hormones, and tyrosine derivatives
Term
since peptides are proteins, ____
Definition
they can't diffuse through the membrane, so they bind to receptors on the membrane and act through a second messenger
Term
The peptide hormones you must know for the MCAT are:
Definition
The anterior pituitary hormones: FH, LH, ACTH, hGH, TSH, and prolactin
The posterior pituitary hormones: ADH and oxytocin
The parathyroid hormone: PTH
The pancreatic hormones: glucagon and insulin
Term
since steroid hormones are lipids, they ___
Definition
diffuse through the membrane and act in the nucleus
Term
the important steroid hormones for the MCAT are:
Definition
adrenal cortex: cortisol and aldosterone
gonadal hormones: estrogen, progesterone, testosterone
Term
tyrosines act by ____
Definition
thyroid hormones diffuse into nucleus, and catecholamines act on receptors on the membrane
Term
The important tyrosine derivatives are:
Definition
thyroid hormones: T3, T4,
catecholamines formed in adrenal cortex: epi and norepi
Term
a high ADH increases ___ and decreases ___
Definition
water reabsorption and blood pressure; water excretion
Term
The anterior pituitary is located in the ___
Definition
hypothalamus
Term
The anterior pituitary secretes what 6 peptide hormones:
Definition
1.hGH
2. adrenocorticotropin
3. thyroid stimulating hormone
4. follicle stimulating hormone
5. leutinizing hormone
6. prolactin
Term
___ stimulates growth in almost all cells of the body
Definition
human growth hormone
Term
___ stimulates the adrenal cortex to release glucocorticoids via the second messenger system using cAMP. stress can cause release
Definition
adrenocorticotropic hormone
Term
___ stimulates the thyroid to release T3 and T4 via camp
Definition
thyroid stimulating hormone
Term
___ promotes lactation by the breasts
Definition
prolactin
Term
The ___, aka ___, extends from the hypothalamus
Definition
posterior pituitary; neurohypophysis
Term
the posterior pituitary secretes what two hormones
Definition
oxytocin and ADH
Term
___ increases uterine contractions during pregnancy and causes milk to be ejected from the breasts
Definition
oxytocin
Term
___ increases water reabsorption and decreases water excretion
Definition
ADH
Term
The adrenal cortex secretes what two hormones:
Definition
aldosterone and cortisol
Term
The adrenal medulla secretes what two:
Definition
epi and norepi
Term
___ increases Na+ reabsorption and H and K secretion
Definition
aldosterone
Term
___ increases blood glucose levels by stimulating glucogenesis in the liver
Definition
cortisol
Term
glucogenesis ___
Definition
is the creation of glucose and glycogen, mainly in the liver
Term
The general effect of T3 (triiodothyronine) and T4 (throxine) is to ___
Definition
increase the basal metabolic rate
Term
___ is releases by the thyroid gland and decreases blood calcium by decreasing osteoclast activity
Definition
calcitonin
Term
the thyroid secretes ___
The parathyroid secretes ___
The pancreas secretes ___
Definition
T3, T4, calcitonin
PTH
insulin and glucagon
Term
insulin is ____
Definition
secreted by beta cells, associated with high energy abundance, lowers blood glucose levels
Term
glucagon is ___
Definition
peptide, release by alpha cells, stimulates glycogenolysis, and gluconeogenesis in liver, net effect is to raise blood glucose levels
Term
glycogenolysis ___
Definition
the breakdown of glycogen
Term
___ is a peptide that increases blood calcium
Definition
parathyroid hormone
Term
production of sperm occurs in the ___
Definition
seminiferous tubules
Term
sertoli cells, stimulated by ___, surround and nurture the sermatocyte and spermatids
Definition
FSH
Term
leydig cells release ___ when stimulated by ___
Definition
testosterone; LH
Term
testosterone is the primary ____
Definition
androgen (male sex hormone)
Term
spermatozoon mature in the ___
Definition
epididymus
Term
oogenesis begins in the _____
Definition
ovaries of the fetus
Term
3 phases of the menstrual cycle
Definition
1. the follicular phase
2. the luteal phase
3. flow
Term
the ___ begins with the development of the follicle and ends at ovulation
Definition
follicular phase
Term
the ___ begins with ovulation and ends with the degeneration of the ___ into the ___
Definition
luteal phase; corpus luteum; corpus albicans
Term
___ is the shedding of the uterine lining lasting approximately 5 days
Definition
flow
Term
once in the fallopian tube, the egg is swept toward the uterus by ____
Definition
cilia
Term
the oocyte goes through the second meiotic division to become an ___ and releases a second polar body
Definition
ovum
Term
___ begins while the zygote is still in the fallopian tube.
Definition
cleavage
Term
The zygote goes through many cycles of mitosis; when the zygote is comprised of eight or more cells, it is called a ___
Definition
morula
Term
The cells of the morula continue to divide for four days forming a hollow ball filled with fluid called a ___
Definition
blastocyst
Term
The blastocyst lodges in the uterus in a process called ____
Definition
implantation
Term
The blastocyst is made up of ____
Definition
embyonic stem cells
Term
upon implantation, the egg begins secreting a peptide hormone called ___ that prevents degeneration of the corpus luteum, and maintains its secretion of estrogen and progesterone
Definition
human chorionic gonadotropin (HCG)
Term
___ in the blood and urine of the mother is the first sign of pregnancy
Definition
Human chorionic gonadotropin
Term
a ___ is formed from the tissue of the egg and the mother, and takes over the job of hormone secretion
Definition
placenta
Term
as the embryo develops past the eight cell stage, the cells become different from each other due to cell to cell interactions. The process where a cell becomes committed to a specialized developmental path is called ____
Definition
determination
Term
The specialization that occurs at the end of development forming a specialized tissue cell is called ___
Definition
differentiation
Term
The formation of the gastrula occurs in the second week after fertilization in a process called ____
Definition
gastrulation
Term
during gastrulation, the three primary germ layers are formed:
Definition
1. ectoderm
2. mesoderm
3. endoderm
Term
the ___ develop into the outer coverings of the body, such as skin, nails, and tooth enamel
Definition
ectodermal cells
Term
the ___ develop develop into the lining of the digestive tract, and into much of the liver and pancreas
Definition
endodermal cells
Term
The ___ is the stuff that lies between the inner and outer coverings of the body; such as muscle, bone, etc
Definition
mesoderm
Term
in the third week, the gastrula develops into a ___
Definition
neurula
Term
in neurulation, the ___ induces the overlaying ectoderm to thicken and form the neural plate
Definition
notochord (made from mesoderm)
Term
the notochord eventually degenerates, while a ___ forms from the neural plate to become the spinal cord, brain, and most of the nervous system.
Definition
neural tube
Term
___ occurs when one cell type affects the direction of differentiation of another cell type
Definition
induction
Term
part of normal cell development is programmed cell death or ____
Definition
apoptosis
Term
apoptosis is essential for development of the ___ and many other things
Definition
nervous system
Term
___ is the break down of ingested foods before they are absorbed into the body
Definition
digestion
Term
The major reaction involved in the digestion of all macromolecules is ___
Definition
hydrolysis
Term
give the seven structures in the basic anatomy of the digestive tract.
Definition
1. mouth
2. esophagus
3. stomach
4. small intestine (duodenum, ileum, jejunum)
5. large intestine (ascending colon, transverse colon, descending colon, sigmoid colon)
6. rectum
7. anus
Term
digestion begins in the ___ with ___
Definition
mouth; alpha amylase contained in the saliva
Term
alpha amylase begins by breaking down ___, with the aid of ___
Definition
the long straight chains of starch into polysaccharides; chewing (increases the surface area of food, which enables more enzymes to act on the food at any one time)
Term
chewed food forms a clump in the mouth called the ____
Definition
bolus
Term
The bolus is pushed into the ___ by swallowing
Definition
esophagus
Term
The bolus is moved through the esophagus by ___
Definition
peristaltic action
Term
___ acts to lubricate the food, helping it to move down the esophagus
Definition
saliva
Term
no digestion occurs in the ____
Definition
esophagus
Term
___ is the wave like motion of smooth muscle that moves food through the digestive tract
Definition
peristalsis
Term
The bolus moves into the stomach through the ____
Definition
lower esophageal sphincter (or cardiac sphincter)
Term
The stomach mixes and stores food, reducing it to a semifluid mass called ___
Definition
chyme
Term
The stomach contains ___ that have ___
Definition
exocrine glands; gastric pits
Term
another important function of the stomach is to begin ____ with the enzyme ____
Definition
protein digestion; pepsin
Term
The low pH of the stomach helps digest proteins by ____
Definition
denaturing them
Term
A full stomach has a pH of ___. This helps to kill ____
Definition
2; ingested bacteria
Term
what are the four major cell types in the stomach
Definition
1. mucous cells
2. chief (peptic) cells
3. parietal (oxyntic) cells
4. G cells
Term
mucous cells secrete ___; line the ___ and ___.
Definition
mucous; stomach wall and the necks of the exocrine glands
Term
mucous is composed of ____ and ___; it ___ the stomach wall and protects the ____. some mucous cells also secrete a small amount of ___
Definition
glycoproteins and electrolytes; lubricates; epithelial lining; pepsinogen
Term
chief cells are found ____; they secrete ___
Definition
deep in exocrine glands; pepsinogen (the zymogen precursor to pepsin)
Term
pepsinogen is activated to pepsin by ___. Once activated, ____
Definition
the low pH in the stomach; pepsin begins protein digestion
Term
parietal cells are found in the ____; they secrete ___
Definition
exocrine glands of the stomach; HCl
Term
parietal cells also secrete ___, which helps the ileum absorb B 12
Definition
intrinsic factors
Term
G cells secrete ___ into the interstitium
Definition
gastrin
Term
the gastrin, a large peptide hormone, is absorbed into the blood and stimulates ___
Definition
parietal cells to secrete HCL
Term
The major hormones that affect the secretion of stomach juices are ___, ___, and ___
Definition
ach, gastrin, and histamin
Term
___ increases the secretion of all cell types; while ___ and ___ mainly inhibit HCl secretion
Definition
ACH; gastrin and histamine
Term
___ digestion begins in the stomach; and no ___ occurs in the stomach
Definition
protein; absorption
Term
about 90% of digestion and absorption occurs in the ____
Definition
small intestine
Term
the small intestine is divided into three parts; from smallest to largest they are:
Definition
duodenum, jejunum, ileum
Term
most of the digestion occurs in the ___, and most of the absorption occurs in the ___
Definition
duodenum; jejunum and ileum
Term
The wall of the small intestine is similar to the wall of the stomach except that the outermost layer contains finger-like projections called ____
Definition
villi
Term
within each villus are a capillary network and a lymph vessel, called a ____
Definition
lacteal
Term
nutrients absorbed through the wall of the small intestine pass into the ____
Definition
capillary network and the lacteal
Term
on the apical surface of the cells of each villus are much smaller finger-like projections called ___ that ____
Definition
microvilli; increase the surface area of the intestinal wall
Term
some of the epithelial cells of the small intestine are ___
Definition
goblet cells
Term
The semi-fluid chyme is squeezed out of the stomach through the ___ and into the ___
Definition
pyloric sphincter; duodenum
Term
the fluid inside the duodenum has a pH of ___ due mainly to ___ secreted by the ___
Definition
6; bicarbonate ion; pancreas
Term
The small intestine is where the action is in ___ and ___
Definition
digestion; absorption
Term
The major enzymes released by the pancreas are:
Definition
trypsin, chymotrypsin; pancreatic amylase; lipase; ribonuclease; and deoxyribonuclease
Term
___ is activated by the enzyme enterokinase. activated ___ then activates the other enzymes
Definition
trypsin; trypsin
Term
___ and ___ degrade proteins into small polypeptides
Definition
trypsin and chymotrypsin
Term
___ hydrolyzes polysaccharrides to dissaccharides and trisaccharides
Definition
pancreatic amylase
Term
___ degrades fat, specifically triglycerides
Definition
lipase
Term
___ is produced in the liver and stored by the gall bladder. It ____
Definition
bile; emulsifies fats
Term
how is bile released
Definition
gall bladder released bile through the cystic duct, which empties into the common bile duct shared with the liver; this empties into the pancreatic duct before connecting to the duodenum
Term
bile emulsifies fats, which means ___
Definition
it breaks it up into small particles without changing it chemically. This increases the surface area of the fat, allowing lipase to degrade it
Term
bile is necessary to ____, but it does not ___
Definition
increase the surface area of the fats; digest the fat
Term
chyme is moved through the intestines by ___. a second type of intestinal motion, ___, mixes the chyme with the digestive juices
Definition
peristalsis; segmentation
Term
the large intestine, or colon, has four parts:
Definition
ascending, transverse, descending, and sigmoid colon
Term
The major functions of the large intestine are ___ and ___
Definition
water absorption and electrolyte absorption
Term
whenever you see large intestine on the MCAT, you should think ____
Definition
water reabsorption
Term
be aware that there is a mutualistic symbiosis between ___ and ___ in the large intestine
Definition
humans and bacteria
Term
___ cannot be digested by humans and is considered roughage
Definition
cellulose
Term
all carbohydrates are absorbed into the bloodstream and carried by the ___ to the liver
Definition
portal vein
Term
The formation of glycogen is called ____. When the blood glucose level decreases, ___ takes place in the liver, and glucose is returned to normal
Definition
glycogenesis; glycogenolysis
Term
carbs are turned into ___ and then into ___ for energy storage
Definition
glucose; glycogen
Term
when the glycogen stores are full, ____
Definition
glucose is converted to fate
Term
all dietary protein is ___ before being absorbed into the blood
Definition
completely broken down to its amino acids
Term
nearly all ammonia is coverted to ___ by the liver, and then excreted in the urine by the kidney
Definition
urea
Term
most of dietary fat consists of ___
Definition
triglycerides
Term
fat becomes globules called ___
Definition
chylomicrons
Term
the chylomicron concentration peaks ___
Definition
1-2 hours after a meal
Term
the major absorption of fat occurs in the ___ and ___
Definition
liver; adipose tissue
Term
____ hydrolyzes the triglycerides in chylomicrons
Definition
lipoprotein lipase
Term
inside the fat and liver cells, triglycerides are reconstituted at the ____
Definition
smooth endoplasmic reticulum
Term
the first stop for most of the digested fat is the ____
Definition
liver
Term
most fatty acids are tranported in the form of free fatty acid, which combines immediately in the blood with ____
Definition
albumin
Term
between meals, 95% of lipids in the plasma are in the form of ___
Definition
lipoproteins
Term
four types of lipoproteins
Definition
very low density LP
intermediate density LP
low density LP
high density lipoprotein
Term
the liver is positioned to recieve blood from the capillary beds of the intestines, stomach, spleen, and pancreas via the ____
Definition
hepatic portal vein
Term
a second blood supply, used to oxygenate the liver is received through the ____
Definition
hepatic artery
Term
all blood received by the liver moves through large flattened spaces called the ___ and collects in the ___, which leads to the ___
Definition
hepatic sinusoids; hepatic vein; vena cava
Term
___ and ___ are two important clotting factors
Definition
prothrombin and fibrinogen
Term
___ is the major osmoregulatory protein in the blood
Definition
albumin
Term
___ are a group of proteins that include antibodies
Definition
globulins
Term
antibodies are made by ___
Definition
plasma cells
Term
the function of the kidney is to excrete ___, maintain ___, and help control ___
Definition
waste products; homeostasis of the body fluid volume and solute composition, plasma pH
Term
kidneys are made up of a ___ and ___
Definition
outer cortex; inner medulla
Term
urine is created by the kidney and emptied into the ____
Definition
renal pelvis
Term
The renal pelvis is emptied by the ___, which carries urine to the ___, which is drained by the ____
Definition
ureter; bladder; urethra
Term
The functional unit of the kidney is the ____
Definition
nephron
Term
blood flows into the first capillary bed of the nephron called the ___
Definition
glomerulus
Term
together, Bowman's capsule and the glomerulus make up the ___
Definition
renal corpuscle
Term
____ forces some plasma through fenestrations of the glomerular endothelium and into ____
Definition
hydrostatic pressure; Bowman's capsule
Term
the fenestrations screen out blood cells and large proteins from entering ____
Definition
Bowman's capsule
Term
The fluid that find its way into Bowman's capsule is called ____
Definition
filtrate/ultrafiltrate/primary urine
Term
filtrate moves from Bowman's capsule to the ___, where most ___ takes place
Definition
proximal tubule; reabsorption
Term
drugs, toxins, and other solutes are ___ into the filtrate by the cells of the proximal tubule.
Definition
secreted
Term
____ are secreted through an antiport system with ____, which is driven by the ____
Definition
hydrogen ions; sodium; sodium concentration gradient
Term
from the proximal tubule, the filtrate flows into the ___
Definition
loop of henle
Term
the loop of henle dips into the ___, and its function is to increase the ____
Definition
medulla; solute concentration, and thus osmotic pressure, of the medulla
Term
The descending loop of henle is _____, therefore ___
Definition
permeable to water and impermeable to NaCl, osmolarity goes up
Term
the ascending loop of henle ____
Definition
is impermeable to water, passively and actively permeable to NaCl
Term
a second capillary bed, called the ___, surrounds the loop of henle and helps to maintain the concentration of the medulla
Definition
vasa recta
Term
The distal tubule reabsorbs ___ and ___, while secreting ___, ___, and ___
Definition
Na+;Ca2+;K+;H+; HCO3-
Term
___ acts on the distal tubule to increase sodium and potassium membrane transport proteins. The net effect is to lower ___
Definition
aldosterone; lower filtrate osmolarity
Term
___ increases the permeability of the cells to water, concentrating the filtrate
Definition
ADH
Term
the distal tubule empties into the ____, which carries ____
Definition
collecting duct; filtrate into the highly osmotic medulla
Term
The collecting duct is impermeable to ___ but sensitive to ___, in its presence ___
Definition
water; ADH; the collecting duct becomes permeable to water
Term
The ___ monitors filtrate pressure in the distal tubule
Definition
juxtaglomerular apparatus
Term
specialized cells in the ja, called ___, secrete ____ which ultimately ____
Definition
granular cells; renin; stimulates the adrenal cortex to secrete aldosterone
Term
trace the pathway of blood through the heart beginning with the left ventricle
Definition
left ventricle > aorta > arteries > arterioles > capillaries > venules > veins > superior and inferior vena cava > right atrium
Term
The previous circulation is called ___
Definition
systemic circulation
Term
what is pulmonary circulation
Definition
right atrium > right ventricle > pulmonary artery > lungs > pulmonary veins > left atrium
Term
the heart contracts automatically, paced by a group of specialized cardiac muscle cells called the ___ located in the ___
Definition
sinoatrial node; right atrium
Term
the SA node is autorhythmic, spreading its contractions to the surrounding cardiac muscles via ___ made from ___
Definition
electrical synapses; gap junctions
Term
The pace of the SA node is ___ than normal heartbeats, but the ____ innervates the SA node, slowing the contractions.
Definition
faster; parasympathetic vagus nerve
Term
The ap then spreads to the ____
Definition
atrioventricular node which is slower to contract, causing a delay which allows the atria to finish their contractions
Term
The ap in the heart travels as follows
Definition
sa node > AV node > bundle of his > purkinje fibers
Term
the purkinje fibers ____
Definition
allow for a more unified, stronger, contraction
Term
the vagus nerve is ___; innervating the ___ and ___; it ___ and ___
Definition
parasympathetic; heart and digestive system; slows the rate of heart contractions and increases digestive activity
Term
___ are elastic, and stretch as they fill with blood
Definition
arteries
Term
___ are microscopic blood vessel and nutrient and gas exchange take place across their walls
Definition
capillary walls
Term
four methods for materials to cross the capillary walls
Definition
1. pinocytosis
2. diffusion through cell membrane
3. movement through pores/fenestrations
4. movement thorough the space between cells
Term
venules and veins are similar in structure to ____
Definition
arterioles and arteries
Term
___ carries blood away from the heart; ___ carries blood toward the heart
Definition
artery; veins
Term
___ contain the most deoxygenated blood
Definition
pulmonary artery
Term
blood pressure increases near the ____ and decreases to its lowest in the ___
Definition
heart; capillaries
Term
inspiration occurs when the ___ of the midbrain signals the ___ to contract
Definition
medulla oblongata; diaphragm
Term
the nasal cavity ____ incoming air
Definition
filters, moistens, and warms
Term
the ___ functions as a passageway for food and air
Definition
pharynx (throat)
Term
The ___ is the voice box and sits behind the ___, which prevents food from entering the trachea during swallowing
Definition
larynx; epiglottis
Term
the ___ lies in front of the esophagus
Definition
trachea
Term
before entering the lungs, the trachea split into the ____
Definition
left and right bronchi
Term
each bronchus branches many more times to become tiny ___, which terminate in grape like clusters called ____ composed of alveoli
Definition
bronchioles; alveolar sacs
Term
oxygen is pick up by ___, which also release carbon dioxide
Definition
red blood cells
Term
98% of the oxygen in the blood binds rapidly and reversible with the protein ___
Definition
hemoglobin
Term
explain the oxygen dissociation curve
Definition
right shift: increase in CO2 pressure, [H+], or temp, decrease in hemoglobin affinity for oxygen
Term
the blood is ___ tissue
Definition
connective
Term
blood in a centrifuge divides into what 3 parts
Definition
plamsa; wbc; rbc
Term
important proteins contained in the plasma are ___, ___, and ___
Definition
albumin, immunoglobulins, and clotting factors
Term
___ transport fatty acids and steroids, as well as acting to regulate the osmotic pressure of the blood
Definition
albumin
Term
plasma in which the clotting protein fibrinogen has been removed is called ___
Definition
serum
Term
____ are like bags of hemoglobin and have no organelles, not even a nucleus, which means they do not reproduce
Definition
erythrocytes
Term
___ do not contain organelles or hemoglobin, they function to protect the body from foreign invaders
Definition
leukocytes
Term
agranular leukocytes include
Definition
monocytes, lymphocytes and megakaryocytes
Term
granular leukocytes include
Definition
neutrophils, eosinophils, and basophils
Term
all blood cells differentiate from the same type of precursor, a ___
Definition
stem cell
Term
___ are small portions of membrane bound cytoplasm torn form megakaryocytes
Definition
platelets
Term
explain the humoral immune response
Definition
-antibodies dissolved in extracellular fluid
-B lymphocytes (B cells)
-lymphoid follicles - appendix, tonsils, and spleen
Term
___ are stimulated by the presence of an antigen
Definition
B cells
Term
B cells, as a result of being stimulated by an antigen, differentiate into ___ and ___
Definition
plasma cells; memory cells
Term
___ cells then produce antibodies that are specific to the antigen that triggered the whole process
Definition
plasma cells
Term
___ cells are cells that retain the memory of the antigen and the type of antibody that needed to be produced
Definition
memory cells
Term
explain the cell mediated response
Definition
- T cells
- no antibodies secreted
- antigen receptors on cells
- destroys bacteria and viruses within host cells
- cytokines
Term
T cells differentiate into ___ and ____ cells
Definition
T helper cells; T cytotoxic cells
Term
cells involved in triggering the immune destruction of tagged cells; they are necessary for B cell activation
Definition
T helper cells
Term
Tc cells _____
Definition
kill infected cells
Term
NK cells are ____
Definition
natural killer cells; they kill cells infected by virus/cause apoprosis
Term
what are the three types of muscle tissue
Definition
skeletal, cardiac, smooth
Term
___ is voluntary muscle
Definition
skeletal
Term
a ___ connects muscle to bone; a ___ connects bone to bone
Definition
tendon; ligament
Term
The muscle ___ is on the larger bone and its ___ is on the smaller bone
Definition
origin; insertion
Term
___ is living tissue
Definition
bone
Term
___ differentiate into osteoblasts
Definition
osteogenic cells
Term
___ exchange nutrients and waste materials with the blood
Definition
osteocytes
Term
___ secrete collagen and organic compounds upon which bone is built, and differentiate into osteocytes
Definition
osteoblasts
Term
___ resorb bone matix
Definition
osteoclasts
Term
bone also stores ___ and ___ and is the site of ___
Definition
calcium; phosphate; blood cell formation
Term
___ is flexible, resilient connective tissue
Definition
cartilage
Term
___ cartilage is the most common and reduces friction and absorbs shock in joints
Definition
hyaline
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