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bio lab
practical 2
93
Biology
Undergraduate 2
05/04/2010

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Term
what is the function of enzymes in the cell?
Definition
speed up reactions
Term
active sites
Definition
regions that can interact w/ the substrate to form an enzyme-substrate complex
Term
formation of benzoquinone
Definition
catechol+oxygen--->benzoquinone+H2O
Term
denatured
Definition
when the structure of the enzyme changes and it no longer acts as a catalyst
Term
activation energy
Definition
the energy needed to initiate reactions. enzymes functions by lowering activation energy
Term
enzyme specificy
Definition
enzymes are globular in shape and have 1 or more active sites each of which is structured so that it bonds q/ a specific substrate. Ex.:despite the structure of catechol and hyrdroquine being very similar, catechol oxidase created a great deal of benzoquinone produced w/ the addition of catechol, but little to no product w/ the addition of hydroquinone
Term
cofactor
Definition
inorganic molecules, usually metallic ions like copper, required by some enzymes to function
Term
catechol oxidase
Definition
works best at 40 degrees celcius and at 7pH (optimum temp/pH)
Term
enzymes
Definition
they are adapted to the enviornment in which they are active. protein catalysts that regulate the rate of chemical reactions within cells
Term
4 factors that can affect enzyme action
Definition
1. temperature- reactions catalyzed by enzymes have a temperature range in which the reaction will occur at optimum level; within this range the reaction rate increases 10% per every 1 degree celcius increase.
2.pH- enzymes function best at pH near neutral (pH 6-8)3. cofactor
Term
aerobic respiration
Definition
cellular respiration
Term
meiosis
Definition
division of cells to produce 4 daughter cells (gametes) w/ a single set of chromosomes. used for sexual reproduction, genetic variation and chromosome update and repair. 1 diploid cell results in 4 daughter haploid cells
Term
mitosis
Definition
division of a cell to produce 2 identical cells. used for growth, replacement and asexual reproduction.
Term
homologous chromosome
Definition
dipliod eukaryotic chromosomes that have nearly identical sequences of genes. after meiosis each of the 4 daughter cells only gets half of the homologous pair; humans have 23. similar size, gene loci (gene location) and staining patterns. NOT identical because they have they may have the same gene locus for eye color but 1 may have the gene for brown eyes and the other the gene for green eyes
Term
sister chromatids
Definition
2 replicated chromosomes as the result of the S stage of interphase, stilled joined together at the centromere forming an X shape. contain identical copies of the DNA molecule.
Term
dipliod
Definition
having each chromosome w/ a nearly identical pair member. each daughter cell produced in mitosis is diploid; humans are diploid (2n) because we get each of our homologous chromosomes from each parent
Term
haploid
Definition
in the life cycle of an organism that reproduces sexually, a cell containing a signle set of chromosomes. an "n" cell; daughter cells produced by meiosis containing only 1 homolog (half the homologous pair)
Term
chromatin
Definition
consists of DNA and protein. uncoiled, uncondensed chromosomes dispersed randomly throughout the nucleus. diffused, very extended form taken by chromosomes when a cell is not dividing
Term
chromosome
Definition
threadlike, gene-carrying structure found in the nucleus. most visible during mitosis and meiosis
Term
centromere
Definition
the region of a duplicate chromosome where 2 sister chromatids are joined and where spindle microtubles attach during mitosis and meiosis. divides at the onset of anaphase during mitosis and anaphase II during meiosis
Term
kinetochore
Definition
the protein structure on chromosomes where spindle fibers attach during division to pull the chromosome apart
Term
cell plate
Definition
a double membrane across the midline of a dividing plant cell, between which the new cell wall forms during cytokinesis. seperates the cytoplasm of a plant cell
Term
cleavage furrow
Definition
a shallow groove in the cell surface near the old metaphase plate. forms to sperate the cytoplasm of an animal cell (pinches inward). the 1st sign of cytokinesis during cell division in animal cells.
Term
interphase mitosis
Definition
precedes mitosis. cells spend about 90-95% of thier lives in interphase. time the cells needs to perpare for mitosis. 3 phases, G1, S, and G2
Term
G1 phase mitosis
Definition
growth phase, increased metabollic activity and replication of organelles
Term
S phase mitosis
Definition
synthesis, DNA is replicated and chromosomes are reproduced
Term
G2 phase mitosis
Definition
cells make proteins required for the upcoming mitotic phase( nuclear division) and cytokinesis( cytoplasmic division)
Term
cell cycle
Definition
interphase (G1, S, G2)---> mitosis (prophase, metaphase, anaphase, telephase)---> cytokinesis
Term
prophase
Definition
1st stage of mitosis. plant cells do not have aster or centrioles; no arrangement of chromosomes; chromatin is condensing into chromosomes; nuclear envelope disappears; microtubles rapidly grow out from centrosomes and centrosomes moe towards the poles
Term
metaphase
Definition
centromeres of chromosomes line up at the equatorial plate; centers of the chromosomes are at the equator of the cell and loose arms of chromosomes fall to either side of the equator
Term
anaphase
Definition
centromeres of each chromosome come apart, seperating sister chromatids; kinetochores pull the duaghter chromosomes centromere along the microtubles towards opposite poles
Term
telophase
Definition
end of mitosis. daughter nuclei appear at the 2 poles as nuclear envelopes form around the chromosomes; chromosomes uncoil; cell as 2 collections of chromosomes because sister chromatids are being pulled in opposite directions. seperate sister chromatids are then called daughter chromosomes.
Term
cytokinesis mitosis
Definition
not part of mitosis. division of the cytoplasm and its content (except DNA); overlaps the last part of mitosis. complete with the seperation of cells
Term
gametes
Definition
ova and sperm cells resulting from cell division that occurs in the gonads (overies and testes) of animals
Term
gametogenisis
Definition
overal production of gametes. begins while the female is stil a fetus
Term
somatic cell
Definition
diploid. non-sex cell contains 46 individual chromosomes (2n). zygote formed by an egg (n) and sperm (n).uses mitosis to divided 1 diploid producing 2 diploid cells
Term
meiosis interphase
Definition
DNA is replicated; DNA is still in the form of chromatin
Term
prophase I
Definition
condensation of chromosomes. pair of homologous chromosomes in a process called synapsis, where portions of the chromosome arms maybe swapped between homologs (crossing over); 4 sister chromatids form a tetrad.
Term
crossing over
Definition
recombitation of genetic material as a result od synapsis
Term
metaphase I
Definition
spindle fibers move homologous pairs to the equator;the individual centromere of a pair lie on opposite sides of the cell equator and are connected to the poles by spindle fibers
Term
anaphase I
Definition
homologous pairs seperate and each homolog is pulled to the opposite pole; chromtids are still whole. each homolog contains 2 sister chromatids. because of crossing over the sister chromatids are no longer identical
Term
telophase I
Definition
homologs are at the poles and a nuclear envelope form. cytokinesis produces 2 haploid daughter cells each w/ 2 sister chromatids for each chromosome
Term
prophase II
Definition
chromatin condenses and nuclear envelope breaks down; chromatids are still attached via their centromeres
Term
metaphase II
Definition
chromosomes align along the equator; centromere are attached to spindle fibers at their kinetochores.
Term
anaphase II
Definition
centromere split and sister chromatids seperate into daughter chromosomes by moving to opposite poles
Term
telophase II
Definition
chromatid are now full chromosomes and are at opposite poles; nuclear envelope reforms around each set of chromosomes
Term
exclusive to meoisis
Definition
2 divisions, creates 4 haploid gametes, pair homologous chromosomes, cross over during prophase I that results in recombination of genetic material
Term
exclusive to mitosis
Definition
produces 2 diploid somatic cells
Term
both meoisis and mitosis...
Definition
duplicate chromosomes in interphase
Term
DNA
Definition
nucleic acid monomer. built by connecting large numbers of nucleotides linked by phosphodiester bonds. consists of a 5-carbon sugar (deoxyribose), a phosphate group, and 4 nitrogenous bases (adenine, gaunine, cytosine and thymine). 2 strands held together by hydrogen bonding between complentary bases. T pairs w/ A using 2 hydrogens bonds and C pairs w/ G using 3 hydrogen bonds. double helix
Term
rRNA
Definition
ribosomal RNA, a component of ribosomes; paired w/ protein makes up ribosomes
Term
tRNA
Definition
transfer RNA. functions as an interpreter in translation. the carrier of individual amino acids. each as a specific anticodon, picks up a specific amino acid and conveys the amino acid to the appropriate codon on mRNA
Term
mRNA
Definition
messenger RNA. the template for protein synthesis. carrys the genetic code written in A,U,G, and C, which directs the placement of amino acids in the protein chain. encodes genetic info. from DNA and conveys it to ribosomes
Term
tRNA and mRNA
Definition
both must be present for DNA synthesis to occur
Term
electrophoresis
Definition
DNA fragments made by restriction enzymes can be sperated by the process of applying high voltage to a solution of charge molecules. DNA (neg charged) will migrate through the agarose gel toward the pos. electrode. the rate of migration of DNA fragments depends on their size and shaped an the gel pore size; small fragments migrate faster than largers ones, so the larger fragments will stay closer to the point of origin
Term
restriction endonucleases
Definition
restriction enzyme. special bacterial enzymes that cut DNA. proteins that bacteria use to prevent the invasion of foreign DNA such as viruses. these enzymes act as DNA scissors cutting foreign DNA into non-functioning peices; they recognize and cut at specific sites along the DNA molecule
Term
precipitated banana DNA
Definition
looks like a white stringy cottony mass
Term
DNA precipitation/DNA isolation method
Definition
1. break open the cell. 2. removing proteins and cellular debris from nucleic acid. 3. final purification of the DNA its self. additio of alcohol will cause DNA to form as a white precipitated at the interphase of the layers because DNA is insoluble in alcohol.
Term
replication
Definition
a semi-conservative process where DNA is replicated. each strand of the double helix is used a a template for synthesis of a new complementary strand producing 2 new daught strands containing 1 old strand and 1 new strand
Term
transcription
Definition
the process of producing RNA from DNA. occurs in the nuclues. gene is transcribed; mRNA is made (mRNA is single stranded); the mRNA will be transported out of the nucleus to the cytoplasm so that protein synthesis can occur
Term
translation
Definition
mRNA is used by ribosomes to insert the correct amino acids in the correct sequence to form the protein coded for that gene. 3 step process; initiation, elongation, termination
Term
initiation
Definition
the binding of the initial tRNA to mRNA that is bound to the smaller ribosomal subunit.
Term
start codon
Definition
AUG
Term
elongation
Definition
the addition of as many amino acids as needed to build the protein. occurs as a new codon moves onto a reading site on the ribosome and the appropriate tRNA connects to it. continues until stop codon appears
Term
termination
Definition
when a stop codn is encountered, the peptide chain is released and the mRNA and ribosomal subunits dissaciate and protein synthesis is terminated.
Term
RNA
Definition
single stranded nucleic acid. made of a 5-carbon sugar (ribose), a phosphate grouph and 4 nitrogenous bases (adenine, guanine, cytosine and uracil). produced from DNA by the process of transcription in the nucleus. RNA is transported out of the nucleus into the cytoplasm so protein synthesis can occur. 3 major types; rRNA,tRNA and mRNA. A pairs with U and T pairs w/ A both using 2 hydrogen bonds and C pairs w/ G using 3 hydrogen bonds.
Term
prokaryote
Definition
single celled organism lacking a nucleus and membrane enclosed organelles. their DNA is a signle circular chromosome. most abundant and oldest group of organisms. consists of eubacteria (true bacteria) and archaea (archaea bacteria or anciant bacteria)
Term
eukaryotes
Definition
domain eukarya. multicellular w/ internal membrane bound organelles. thier DNA consists of multiple chromosomes. they reproduce sexual via meiosis. some have cells walls made of cellulose or chitin. thier plasma membrane consists of glycerol bonded to strait chained fatty acids
Term
prokaryotes in the archaea domain
Definition
have adpated to extreme enviornemnts such as high heat (thermophiles) and salts (halophiles). some grown in anaerobic conditions and generate methane (methanogens)most have cells walls but are different than bacteria because peptidoglycan is lacking. their plasma memebrane is diff. in structure from bacteria and consists of glycerol bonded to branched fatty acids
Term
hans christian gram
Definition
developed a staining procedure, gram staining, that is used to distinguish the bacterial groups. staining is based on the vary composions of cell walls in diff bacteria species
Term
primary stain
Definition
crystal violet. gram pos and gram neg both initially turn violet
Term
mordant
Definition
gram's iodine; added 2nd. results in a CV-I complex to form within gram neg and gram pos cells
Term
decolorizer
Definition
alcohol; added 3rd when added to gram pos. cell walls are dehydrated, pores shrink, permeability decreases, CV-I complex is retained and cell remain violet. gram neg; lipids are extracted from cell walls, porosity increases, CV-I is removed and cells turn colorless
Term
counter stain
Definition
safranin; added last. gram pos cells are not affected and remain violet. gram neg cells take up the stain and become red
Term
prokaryotes in the domain bacteria
Definition
most have cell walls comprised of peptidoglycan. have plasma membranes made of gylcerol bonded to straight chianed fatty acids
Term
gram pos. bacteria
Definition
have think peptidoglycan cell walls and retain purple color when stained w/ crystal violet
Term
gram neg. bacteria
Definition
have double cell walls; a think peptidoglycan inner wall and a outer wall made of carbohydrates, proteins and lipids. these cells retain the red color when stained w/ safranin
Term
3 basic shaped of bacteria
Definition
bacilli are rod shaped. cocci and spherical shaped. spirilla are spiral shaped.
Term
3 arrangements of bacteria
Definition
chains (strepto), clusters (staphylo) and by twos (diplo)
Term
bacterial colony
Definition
a single bacterium multiples to form a colony; a colony consists of millions of cells that arise from 1 cell. each colony exhibits specific colonial morphology
Term
ways to identify bateria species
Definition
by their bacteriology (growth patterns), morphology (size and shape), their biochemistry ( how they obtain their carbon sources) their DNA sequences, or staining procedures
Term
methanogens
Definition
grown in anaerobic conditions using CO2 to generate methane
Term
halophiles
Definition
grow in salty enviornments containing 10% NaCl
Term
hyperthermophiles
Definition
gorw at temps of 80 degrees celcuis or more.
Term
steps of gram staining (13)
Definition
Term
2 basic needs of prokaryotes
Definition
acquire chemical energy by producing ATP ( some are photosynthetic and some are chemosynthetic) and acquiring carbon in a form that can be used to synthesize other organic molecules used to build cells
Term
fermentation
Definition
C6H12O6---> 2CO2+ 2C2H5OH + energy occurs under conditions of alcohol starvation. produces lactic acid or ethanol and carbon dioxide
Term
alcohol fermentation
Definition
pyrivate molecules are reduced to CO2 and ethanol. the chemical reaction of yeast on sugars
Term
phenol red
Definition
the reagent used to test for CO2 to measure metabolic rate. acidic pH is produced when CO2 enters the fluid. becomes yellow as pH goes down and pink purple is pH is alkaline
Term
forumla for oxygen consumption
Definition
ml O2/mass in grams/time in hours
Term
mitochondria
Definition
Term
photosynthesis
Definition
6CO2 +12H2O + light energy--->C6H12O6 +6O2 +6H20
Term
chloroplast
Definition
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