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biol112 exam 1 lectures
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164
Biology
Undergraduate 1
01/28/2012

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Term
carbohydrates occur as: (2)
Definition
-sugars
-starches
Term
functions of carbohydrates: (3)
Definition
-energy storage (sugars and starches)
-structural
-dietary energy (ATP)
Term
monomers of carbohydrates are called ___________. 2 examples.
Definition
monosaccharides. glucose and fructose
Term
a disaccharide of carbohydrates is the __________ of 2 monomers by ________ linkages. examples are:
Definition
condensation, glycosidic.

examples : sucrose (table), maltose (malt), and lactose (milk)
Term
examples of polysaccharide carbohydrates in plants: (2)
Definition
-cellulose (for the cell wall)
-starch (energy stored)
Term
example of polysaccharide carbohydrate in animals
Definition
glycogen in liver
Term
what is the structure of a fatty acid?
Definition
hydrophilic head (COOH) and hydrophobic tail (long hydrocarbon chain)
Term
what does hydrophilic mean?
Definition
loves water
Term
what does hydrophobic mean?
Definition
hates water
Term
what is the function of fatty acids? (3)
Definition
-long term energy storage (for fats; like hibernating animals)
-hormones (for steroids)
-membranes (the phospholipid bilayer of a cell membrane)
Term
an unsaturated fatty acid has what? What is the difference between a saturated fatty acid and an unsaturated fatty acid?
Definition
unsaturated fatty acid has double bonds (better for you than saturated).

saturated fatty acid has all carbon atoms filled, so it has all the H groups needed.
Term
where are steroids synthesized?
Definition
the liver
Term
what is the monomer of proteins?
Definition
amino acids
Term
what is the general structure of an amino acid? how many amino acids are there?
Definition
-20 amino acids
-each amino acid differs in its "r" group
-each amino acid has an amino group (NH2), a carboxyl group (COOH), a side "R" group, and a central C atom
Term
what is the polymer of proteins?
Definition
a polypeptide (protein)
Term
what is the bond called that forms between amino acids?
Definition
peptide bond
Term
how are polymers of proteins formed?
Definition
by condensation of many amino acids
Term
when two amino acids combine what is the structure called?
Definition
dipeptide
Term
what two groups of 2 different amino acids does a peptide bond form between?
Definition
a C-N bond found between carboxyl C of one amino acid and amino N of another
Term
what are enzymes? what are their functions?
Definition
proteins that cataylze reactions
Term
what are examples of structural functions of proteins? (3)
Definition
-hair
-fingernails
-silk
Term
Functions of proteins (6)
Definition
-enzymes (lysozyme and alcohol dehydrogenase)
-structure (collagen, hair)
-storage
-transport (microtubules, muscle proteins)
-immunity
-storage proteins (seeds, milk, egg white)
Term
what is the primary structure of a protein?
Definition
the unique sequence of amino acids arranged in a long chain
Term
what is the secondary structure of a protein? (2)
Definition
-pattern of hydrogen bonds between amino acids in a long chain
1) alpha helix: hydrogen bonds join the NH group in one peptide bond and the C=O group nearby
2) B pleated sheets: joining of the same NH and C=O bond but amino acids involved are either on different chains or in segments of same chain that bend back and lie close to each other (silk)
Term
what is the tertiary structure of a protein?
Definition
-globular (what most enzymes are)
-held together by a variety of bonds (ionic, hydrogen, disulfide, hydrophobic interactions)
Term
what is the quartenary structure of a protein?
Definition
-made up of several polypeptide chains that must fit together to form a functional protein
-hemoglobin is an example
Term
what is the main protein of connective tissue in animals
Definition
collagen
Term
what is an actin filament? what does it provide for cells?
Definition
-actin molecule = 1 globular protein
-mechanical support in cells
Term
what is an SNP?
Definition
single nucleotide polymorphism

a single amino acid substitution in a protein can cause disease (like sickle cell anemia)
Term
4 steps to how an enzyme works
Definition
1) enzyme available with empty active site
2) substrate binds to enzyme
3) substrate is converted to products
4) products are released
Term
what do catalysts do? (3)
Definition
-increase the rate of reaction
-lower energy of activation
-react with specific substances called substrates
Term
What is lock and key fit (binding) refer to?
Definition
-the exact fit of an enzyme (lock) and the substrate (key) when an enzyme binds to an active site
Term
what are coenzymes?
Definition
-some enzymes will not bind to substrate unless coenzymes (Ca, Fe) are present
Term
what are the four types of inhibition?
Definition
1) competitive inhibition
2) non competitive inhibition
3) reversible
4) irreversible
Term
what is competitve inhibition?
Definition
when there are compounds similar to the substrate that compete with the substrate by binding to the enzyme.
Term
What is non competitive inhibition?
Definition
inactivates crucial groups on enzyme's active site
Term
what is reversible inhibition?
Definition
the enzyme structure is unaltered
Term
what is irreversible inhibition?
Definition
when the enzyme structure is altered
Term
what are allosteric enzymes?
Definition
-exist in two or more states because they have two or more binding sites
-change from one shape to another depending on which site(s) is occupied
-binding of molecules to regulatory site changes shape and therefore its activity
-binding of allosteric inhibitors to regulatory site causes distortion of active site --> poor enzyme activity
Term
what are five factors that affect enzyme activity?
Definition
1. inhibitors
2. allosteric enzymes
3. pH
4. temperature
5. hormone or endocrine disrupters
Term
how can pH affect enzymes?
Definition
-the surrounding pH can change the ionic charges on an enzymes "R" group
Term
at what pH do most enzymes work best?
Definition
pH 7
Term
how does temperature affect enzyme activity?
Definition
-increases the rate of reaction
Term
what happens to an enzyme when the temperature passes 60 degrees C?
Definition
-enzyme denaturation: the destruction of the 3D structure
Term
what are hormone or endocrine disrupters?
Definition
-environmental chemicals that affect the function of the endocrine system i.e. they act as imposters of naturally occurring estrogen and other hormones
-DDT
Term
what are the two nucleic acids?
Definition
-deoxyribonucleic acid (DNA)
-ribonucleic acid (RNA)
Term
what is the function of DNA?
Definition
-genetic information
Term
what is the function of RNA?
Definition
-direct the synthesis of proteins (transcription, translation)
Term
what are the monomers of nucleic acids?
Definition
-nucleotides
Term
what are the three parts that a nucleotide is composed of?
Definition
-a pentose (5 carbon) sugar
-a nitrogenous base
-a phosphate roup
Term
what is the sugar in RNA?
Definition
ribose
Term
what is the sugar in DNA?
Definition
deoxyribose
Term
what is the difference in bases between DNA and RNA?
Definition
-DNA has cytosine, thymine, adenine, and guanine
-RNA has cytosine, uracil, adenine, and guanine
-Therefore, DNA has thymine, but RNA has uracil
Term
which bases are pyrimidines?
Definition
-cytosine
-thymine
-uracil
Term
which bases are purines?
Definition
-adenine
-guanine
Term
what is the backbone of DNA called?
Definition
the sugar phosphate backbone
Term
what is the structure of DNA? who discovered it?
Definition
-double helix
-Watson and Crick
Term
What is the difference between a dehydration synthesis reaction (condensation reaction) and hydrolosis?
Definition
-condensation joins together two molecules with the LOSS of water
-hydrolosis breaks apart a large molecule into two molecules with the ADDITION of water
Term
why is microscopy importation? what does it provide?
Definition
-important in study of cell structure
-provides enlargement and resolution
Term
Resolution increases with __________ wavelength.
Definition
reduced
Term
What is a light microscope?
Definition
-enlargement provided by objective lens and ocular lens
-glass lenses
-illumination provided by light
Term
what is a transmission electron microscope (TEM)?
Definition
-illumination provided by electron beam (shorter wavelength)
-very high resolution
-beam passes through specimen
-observation is made under Vacuum so that electrons are prevented from being absorbed by air or deflected
Term
what is a scanning electron microscope? (SEM)
Definition
-electrons do not pass through the specimen
-lower resolution than TEM
-great advantage = great depth of focus (three dimension)
Term
what are the four unique characteristics of eukaryotes?
Definition
1. membrane-bound organelles (ER, Golgi, lysosomes, mitochondria, cell wall (in plants))
2. nucleolus
3. nucleus
3. cytoskeleton (microtubules, intermediate filaments, microfilaments)
Term
Major differences between prokaryotes and eukaryotes
Definition
-prokaryotes: smaller, simpler, most do not have membrane bound organelles--bacteria and archaea
-eukaryotes: larger, more complex, membrane bound organeles -- protists, plants, fungi, and animals
Term
what do plant cells have that animal cells do not? (2)
Definition
-chloroplasts
-cell wall
Term
What do animal cells have that plant cells do not?
Definition
centrioles
Term
what is the largest organelle?
Definition
the nuceleus
Term
What are the three components of the nucleus?
Definition
1. chromosomes
2. nuclear membrane
3. nucleolus
Term
what is chromatin?
Definition
-contains DNA and histones in nucleosomal configuration; condensed chromosomes
Term
what are nuclear pores and where are they found?
Definition
-found in the nuclear membrane
-allow for the passage of RNA in and out of the nucleus
Term
the nuclear membrane is what kind of membrane?
Definition
phospholipid bilayer with integrated proteins
Term
nucleoli contain hundreds of copies of only one type of genes. what type of genes are these?
Definition
-ribosomal RNA genes
Term
when are the nucleoli most distinctly seen?
Definition
during interphase
Term
each ribosome is composed of how many subunits?
Definition
two. one large and one small.
Term
the components of ribosomes (2)
Definition
-r proteins and rRNA
Term
where are ribosomes first partially assembled?
Definition
the nucleoli. and are called pre-ribosomes.
Term
what is the function of ribosomes
Definition
-translation (protein synthesis)
Term
What are the three aspects of the central dogma?
Definition
1. synthesis of mRNA in the nucleus
2. movement of mRNA into cytoplasm via the nuclear pore
3. syntehsis of protein in the cytoplasm
Term
what is the function of the rough endoplasmic reticulum?
Definition
-protein synthesis
Term
what is the function of the smooth endoplasmic reticulum?
Definition
-lipid and steroid synthesis (regulate calcium concentration and regulate drug metabolism)
Term
what is the difference between the rough ER and the smooth ER? (structural)
Definition
-rough ER has ribosomes attached to the outer (cytoplasmic) surface
-smooth ER has no attached ribosomes
Term
what are the components of the Golgi complex?
Definition
-stack of flattened membranous sacs surrounded by a halo of vesicles
Term
what is the function of the Golgi?
Definition
-sorts, modifies, and repackages molecules
-cis (receiving side) and trans (sending off side)
Term
How does the Golgi change the proteins? (2)
Definition
1. removal of amino acids
2. addition of functional groups
Term
what is a lysozyme?
Definition
-membrane bound sac containing hydrolytic enzymes
Term
what is the function of lysozymes?
Definition
-DIGESTION of viruses, damaged organelles, cellular macromolecules --> into monomers that are reused by the cell
Term
where does cellular respiration take place?
Definition
the mitochondria
Term
what is the structure of mitochondria
Definition
-double membrane (internal membrane thrown into folds called CRISTAE)
-contains unique DNA called mtDNA
Term
By what mechanism does mitochondria reproduce?
Definition
binary fission
Term
what is the function of mitochondria
Definition
-ATP production (by aerobic cellular respiration)
-ATP needed to power all chemical reactions in cells
Term
what is the endosymbiotic theory?
Definition
-the theory that postulates that mitochondria might have once been free-living prokaryotes that became incorprated into eukaryotes establishing a symbiotic relationship.
Term
What features of mitochondria support the endosymbiotic theory?
Definition
-the similarity between mitochondria and prokaryotic protein synthesis machinery
-transcription and translation
-have own DNA
-replicate by binary fission
Term
What is mitochondrial DNA (mtDNA) now used as an indicator of?
Definition
evolutionary divergence in the study of eovlution

better than DNA because rate of mtDNA evolution is faster
Term
what is the structure of peroxisomes?
Definition
-bounded by a single layer membrane
-often have crystalline granulate core (enzyme arrays)
Term
what are the three funtions of peroxisomes?
Definition
-detoxification in the liver
-transfer hydrogen from toxic substances to oxygen producing HYDROGEN PEROXIDE
-some break fatty acids into smaller molecules, which are transported to mitochondria for cellular respiration
Term
what are the three unique plant characteristics?
Definition
plastids, cell wall, and vacuoles
Term
are plastids descendants of free-living bacteria?
Definition
possibly, they are found in photosynthetic eukaryotes (plants and protists)
Term
what is the function of plastids?
Definition
food production and storage
Term
what are the three plastids
Definition
1. chloroplasts
2. chromoplasts
3. amyloplasts
Term
what are chloroplasts?
Definition
-photosynthetic organelles
-CO2 + H2O + light energy = carbohydrate
Term
what is the green pigment contained in chloroplasts?
Definition
clorophyll
Term
what are chromoplasts?
Definition
plastids that synthesize and store yellow and orange pigments
Term
what are amyloplasts?
Definition
plastids that store starch (potatoes and roots)
Term
what is the function of the cell wall
Definition
-protection and support
-water in cell exerting outward pressure on their walls, cementing together of adjacent cells
Term
what are the components of the cell wall?
Definition
-thick, porous cell walls outside the plasma membrane
-mainly cellulose and other fibers
-flexible
Term
what does porous mean in reference to the cell wall?
Definition
-allows passage of water and dissolved substances
Term
what are vacuoles?
Definition
-membrane covered sacs
Term
what are the functions of vacuoles?
Definition
-contian fluid, food, pigments, and toxic substances (variety of functions)
Term
what is a tonoplast?
Definition
-a large central vacuole that is part of the endomembrane system
Term
what are the three types of protein fibers in the cytoskeleton?
Definition
1. microtubules (cilia, flagella, basal body)
2. intermediate filaments
3. microfilaments
Term
what is the function of the cytoskeleton?
Definition
-provides framework for cell shape and ovement
Term
what are microtubules?
Definition
-hollow tubes made of globular proteins
Term
what are the functions of microtubules?
Definition
-cell shape
-cell motility
-provides tracks on which organelles can move
-spindle movement of chromosomes during cell division
Term
what are cilia and flagella?
Definition
-thread like microtubules grown from a basal body
-a circle of 9 pairs of microtubules
-1 pair in middle
Term
what are centrioles?
Definition
-consist of one pair of microtubules at right angles to each other
-these separate to opposite poles providing anchors for mitotic spindle fibers during cell division
Term
what is the function of intermediate filaments?
Definition
-structural support
-maintenace of cell shape
Term
what are the functions of microfilaments?
Definition
-muscle contration
-cytoplasmic sreaming
-endocytosis, exocytosis
-maintenance of or changes in cell shape
Term
what are the three components of the fluid mosaic model?
Definition
-lipids
-proteins
-carbohydrates
Term
what role do lipids play in the fluid mosaic model?
Definition
-phospholipid bilayer
-hydrophilic heads and hydrophobic tails
Term
what role does cholesterol play in the fluid mosaic model?
Definition
cholesterol reduces fluidity but prevents membrane solidifcation at cold temperatures
Term
what kinds of molecules pass easily through a phospholipid membrane?
Definition
small and hydrophobic molecules
Term
what are the two types of proteins found in the fluid mosaic model?
Definition
-intrinsic (integral) proteins
-extrinsic (peripheral) proteins
Term
what are intrinsic (integral) proteins?what is their function?
Definition
-these have hydrophobic regions and penetrate the bilayer, extending from one side to the other (like channel proteins)
-their function is to transport large molecules from the outside to the inside of the cell and vice versa (transport proteins)
Term
what are extrinsic (peripheral) proteins? what are their functions?
Definition
-these are found on one surface only
-they lack hydrophobic regions and are not completely embedded in the bilayer
-varied functions: carrier proteins, cell to cell recognition proteins, glycoproteins, receptor proteins, intercellular junctions, and enzymatic proteins
Term
what are proteins that contain carbohydrate molecules called?
Definition
-glycoproteins (recognition proteins)
Term
what are some examples of signal (cell-cell recognition/glycoprotein) proteins?
Definition
-blood proteins
-human leukocyte antigens
-immunoglobin
Term
What are the six functions of membrane proteins?
Definition
1. Cell recognition and adhesion
2. Transport
3. Membrane proteins
4. Signal transduction
5. Endocytosis and exocytosis
6. Attachment to the cytoskeleton and extracellular matrix
Term
What is homotypic bonding?
Definition
when the same molecule STICKS out of both cells and the exposed surfaces bind to each other (same protein on two cells)

-example = sponge cells
Term
what is heterotypic bonding?
Definition
when different proteins from two types of cells have complementary binding surfaces

-example: different mating type gametes
Term
What are three types of cell recognition and adhesion?
Definition
1. homotypic bonding
2. heterotypic bonding
3. intracellular junctions
Term
What are the four types of intracellular junctions?
Definition
1. tight junctions
2. desmosomes
3. gap junctions
4. plasmodesmata
Term
What are tight junctions? What is their function?
Definition
-seal areas between adjacent epithelial animal cells
-prevent movement of molecules through intracellular membrane spaces
-cannot pass through tight junctions
Term
What are desmosomes? what are their funtion?
Definition
-provide anchoring between cells, permitting material to move around them in the intracellular space
-KERATIN fibers extend through the cytoplasm from one plaque to the other providing great stability
-looks like the clump of half of a button
-found in areas of high stress (cervix cells and elbow cells)
Term
what are gap junctions? what do they allow?
Definition
-protein channels linking adjacent ANIMAL cells
-direct passage of ions and small molecules facilitating communication
-flow of substances from one cell to the next
Term
what are connexons?
Definition
-found in gap junctions
-protein channels linking adjacent cells
Term
what are plasmodesmata? what are their function?
Definition
-strands of cytoplasm connecting some adjacent PLANT cells
-strands pass through gap in cell walls and function as communication bridges
= to gap junctions in animal cells
Term
What are the two types of transport?
Definition
active and passive
Term
what is diffusion?
Definition
-type of passive transport
-random movement of SOLUTES (small) towards equilibrium
-net movement from regions of higher concentration to regions of lower concentration
Term
what types of molecules easily cross membranes by diffusion?
Definition
small uncharged molecules

cross by slipping inbetween the hydrophilic heads of the membrane
Term
What is the rate of diffusion dependent on?
Definition
-concentration: the greater the concentration, the faster the substances diffuse

-oxygen, nitrogen, ethanol = fast
-glycerol (large, uncharged) = slow
Term
What types of molecules do not readily pass through membranes?
Definition
charged and/or polar molecules (amino acids, sugars, ions) because the interior of the membrane is hydrophobic
Term
what is osmosis?
Definition
-type of passive transport because no metabolic energy is required
-the diffusion of WATER across membranes
Term
how does the water diffuse in osmosis (from an area of what concetration to what concentration)
Definition
-water will diffuse from a region of higher concentration (lower concentration of solutes) to a region of lower concentration (higher concentration of solutes)
Term
what does isotonic mean?
Definition
has equal concentration of solutes
Term
what does hypertonic mean?
Definition
has higher total solute concentration than the other solution with which it is being compared
Term
what does hypotonic mean?
Definition
-has lower total solute concentration than the other solution with which it is being compared
Term
what are protein channels? what do they do?
Definition
-integral membrane proteins form channels through the phospholipid bilayer
-channels are lined with POLAR AMINO ACIDS and water on the inside to bind to polar or charged substances and allow them to pass
-when a stimulus binds, the channel protein opens, and the polar substnace diffuses across the membrane
-some channels are gated
Term
what is facilitated diffusion?
Definition
-a carrier protein combines with a specific substance and moves it from one side to the other (DOWN a concentration gradient)
-a carrier molecule transports substances such as glucose
Term
what is active transport? what does it require?
Definition
-permits molecules to move AGAINST a concentration gradient and requires ATP
Term
what type of transport is a sodium potassium pump?
Definition
active transport
Term
what is the function of the sodium potassium pump?
Definition
-maintains LOWER concentration of Na+ and Ca2+ INSIDE the cell
-maintains HIGHER concentration of K+ inside the cell

-Na+ transported OUT
-K+ transported IN
****3 Na+ OUT for every 2K+ IN (for each mole of ATP used)

-the pumping is accomplished by transport proteins with two configurations
Term
what are the two classes of transport proteins?
Definition
1. uniports
2. coupled transport systems
Term
what are uniports?
Definition
-transport proteins that transport ONE type of solute in one diffusion
Term
what are coupled transport systems? what are the two types and what do they do?
Definition
transport proteins that transport TWO OR MORE different solute but neither solute can be moved unless the other is present

1. symport: if the coupled solutes are transported in the SAME direction
2. antiport: if the solutes are transported in OPPOSITE directions (like the sodium potassium pump)
Term
What are the two functions of signal transduction?
Definition
1. information processing
2. energy transformation
Term
how does information processing of signal transduction work?
Definition
-membrane proteins conduct signals (signal molecule) from OUTSIDE the cell that trigger changes inside the cell
-signal binding induces a change in the receptor protein causing some effect INSIDE the cell
-signal molecule outside --> effect inside
Term
how does energy transformation of signal transduction work?
Definition
-membranes of chloroplast and mitochondria are specialized for the transformation of energy
-a membrane protein / pigment absorbs SOLAR energy
-the membrane protein transfers the energy to ADP to form ATP (chemical energy)
Term
What are the three types of endocytosis?
Definition
1. phagocytosis
2. pinocytosis
3. receptor mediated endocytosis
Term
what is the function of endocytosis?
Definition
-transport of LARGE particles
-membrane changes shape, pinching off small sacs and resealing
Term
non-specific types of endocytosis (2)
Definition
phagocytosis and pinocytosis

-the pseudopodia do not choose which LARGER food particles to engulf and digest
Term
what is receptor mediated endocytosis?
Definition
-the food particles first bind to specific protein receptors
-invagination or pits form
-cytoplasmic surface of the pit becomes coated with CLATHRIN
-vesicle is transported to the cytoplasm
Term
What is the 1st law of thermodynamics?
Definition
Energy cannot be created or destroyed, but it can be transformed from one kind to another
Term
What is the second law of thermodynamics?
Definition
one usable form of energy cannot be completely converted to another usable form; that is, in every energy transaction, useful energy decreaes
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