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Microbiology
Test 2
126
Microbiology
Undergraduate 2
03/06/2011

Additional Microbiology Flashcards

 


 

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Term
nutrient that must be provided
Definition
essential nutrient
Term
nutrient that must be supplied in large amounts
Definition
macronutrient
Term
nutrient that lacks carbon and hydrogen
Definition
inorganic nutrient
Term
nutrient that contains carbon and hydrogen
Definition
organic nutrient
Term
primary energy source is sunlight
Definition
photo- autotroph or heterotroph
Term
primary energy source is a chemical compound
Definition
chemo- autotroph or heterotroph
Term
use inorganic substances for energy
Definition
autotrophs
Term
use organic substances for energy
Definition
heterotrophs
Term
ideal solute state of a cell
Definition
hypotonic
Term
solute concentration is lower on the outside of the cell
Definition
hypotonic
Term
solute concentration is lower on the inside of the cell
Definition
hypertonic
Term
uses oxygen during metabolism and can process toxic oxygen and byproducts
Definition
aerobe
Term
does not require oxygen to grow, but favors it
Definition
facultative anaerobe
Term
cannot grow in normal atmospheric concentrations of O2, but does need small amounts for metabolism
Definition
microaerophile
Term
lacks ability to utilize O2 during metabolism
Definition
anaerobe
Term
does not utilize O2 but can grow in the presence of O2 because it can process toxic O2 byproducts
Definition
aerotolerant anaerobe
Term
relationship is necessary and mutually beneficial
Definition
mutualism
Term
one oragnism benefits while the other is neither benefited nor harmed
Definition
commensalism
Term
both organisms benefit, but it is not necessary for either organism's survival
Definition
synergism
Term
organisms live together in a close relationship
Definition
symbiosis
Term
one organism recieves nutrients from and at the expense of the other
Definition
parasitism
Term
organisms living together compete for nutrients
Definition
antagonism
Term
time it takes to go from a single cell to two daughter cells
Definition
generation/doubling time
Term
processes that result in the synthesis of cell molecules and structures; usually requires energy
Definition
anabolism
Term
processes that result in the break down of the cell molecules and structures; usually releases energy
Definition
catabolism
Term
macromolecules that increase the rate of a chemical reaction without being a product or reactant
Definition
enzyme
Term
the amount of energy necessary for the reaction to occur
Definition
activation energy
Term
enzymes that consist soley of protein
Definition
simple enzyme
Term
site on the enzyme where substrates bind and the reaction occurs
Definition
active site
Term
only certain substrates can bind to an enzyme due to constarints of the active site on physical characteristics such as size, shape, and charge
Definition
lock-and-key model
Term
enzymes that function outside the cell; often involved in breaking down nutrients or wastes
Definition
exoenzymes
Term
enzymes that function inside the cell; most metabolic enzymes
Definition
endoenzymes
Term
enzymes that are not always present
Definition
constitutive enzymes
Term
enzymes which presence can be turned on or turned off
Definition
regulated enzymes
Term
enzymes that form covalent bonds between substrates
Definition
ligases
Term
enzymes that remove electrons from one substrate and add them to another; NAD and FAD often serve as coenzymes
Definition
oxidoreductases
Term
enzymes that catalyze steps of metabolic regulation that "set the pace" for the entire pathway
Definition
pacemakers
Term
chemical reactions that release energy
Definition
exergonic
Term
chemical reactions that require energy
Definition
endergonic reactions
Term
enzymes that breakdown proteins into amino acids
Definition
proteases
Term
removal of amino group from amino acids so that carbon backbone can be shuttled into Krebs cycle
Definition
deamination
Term
sum of the genetic material within a cell or organism
Definition
genome
Term
the basic functional units of the genetic material
Definition
genes
Term
the study of genes
Definition
genetics
Term
all the genes that make up an organism's genetic material
Definition
genotype
Term
all the traits that characterize an organism; can change according to gene expression
Definition
phenotype
Term
region of DNA "upstream" of the begining of the gene
Definition
promoter
Term
set of genes that are regulated simutaneously in prokaryotes
Definition
operon
Term
bind to the promoter region of a gene where they recruit RNA polymerase to promote transcription
Definition
transcription factors
Term
a change in the DNA that results in a change in phenotype
Definition
mutation
Term
an unaltered phenotype
Definition
wild type
Term
an altered phenotype due to mutation
Definition
mutant
Term
a physical or chemical agent that damages DNA
Definition
mutagen
Term
what is being transferred during conjugation; can be either plasmid or chromosomal DNA
Definition
F factor
Term
cells capable of accepting the free DNA
Definition
competent
Term
process similar to transformation in eukaryotes
Definition
transfection
Term
sections of DNA that can jump from one location in the chromosome to another, from chromosome to plasmid, or from plasmid to chromosome
Definition
transposons
Term
destruction of all microbial life
Definition
sterilization
Term
destruction of most microbial life on an inanimate surface
Definition
disinfection
Term
destruction of most microbial life on a living surface
Definition
antisepsis
Term
mechanical removal of most microbes
Definition
decontamination
Term
kill bacterial endospores
Definition
sporicidal
Term
ability of the cell to reproduce and be metabolically active
Definition
cell viability
Term
how do cells digest and absorb nutrients when they have a cell wall?
Definition
through osmosis or diffusion
Term
explain the process of osmosis and diffusion
Definition
movement of water across semipermeable membrane down concentration gradient; diffusion is movement of particles down concentration gradient that results from random motion of particles and their collisions with one another in space
Term
what are the three types of diffusion and how do they differ?
Definition
simple- no barrier; facilitated- with help of carrier protein; active- can move up or down concentration gradient with help of carrier protein and requires energy
Term
what are the three mechanisms of active diffusion?
Definition
carrier-mediated- carrier protein moves with or against concentration; group translocation- coupled with another reaction and molecule is chemically modified; bulk transport- large molecules or quantities
Term
which of the solute states of a cell is ideal for life?
Definition
hypotonic
Term
explain how temperature might affect cell growth?
Definition
different bacteria thrive in different temperatures; minimum, maximum, optimum
Term
besides temp what are three other environmental factors that affect microbial growth?
Definition
gases, pH, osmotic pressure, radiation, hydrostatic pressure, water content
Term
equation of microbial growth
Definition
Nf= (Ni) x 2^n
Term
how does an enzyme speed up a reaction?
Definition
by lowering the threshold (the amount of energy required for a reaction to occur)
Term
describe synthesis/dehydration
Definition
builds macromolecules; requires ATP; produce water; utilize ligase
Term
describe hydrolosis
Definition
breaks down macrmolecules; requires water; releases ATP
Term
describe transfer reactions
Definition
utilize oxidoreductases enzymes that remove electrons from one substrate and add them to another; NAD and FAD often serve as coenzymes
Term
How is metabolism regulated?
Definition
by enzymes
Term
Describe competitive inhibition.
Definition
a molecule resembling the substrate binds to the active site of an enzyme blocking the ability of substrate to bind
Term
describe noncompetitive inhibition
Definition
a molecule binds to a site of the enzyme outside the active site to prevent or enhance activity of the enzyme
Term
what are the three major processes through which ATP is formed
Definition
substrate-level phosphorylation, oxidative phosphorylation, photophosphorylation
Term
what are the major sources of energy in the cell
Definition
carbs, proteins, and lipids
Term
What are the major macromolecular building blocks and what macromolecules do they build?
Definition
monosacharides which build carbs, amino acids which build proteins, fatty acids which build lipids, nitrogen bases which build nucleic acids, and vitamins which build enzymes
Term
what is the purpose of glycolosis?
Definition
to break down glucose
Term
what is the starting material of glycolosis?
Definition
glucose (or another 6 carbon sugar)
Term
what are the products of glycolosis?
Definition
2 pyruvate, 2 ATP (net), 2 NADH, 2 H2O
Term
where does glycolosis take place?
Definition
cytoplasm
Term
what is the pacemaker of glycolosis?
Definition
2nd phosphorylation step before the 6C sugar is split
Term
What is the purpose of the Kreb's cycle?
Definition
harvest energy from pyruvate in the form of NADH and FADH2
Term
what is the starting material of the Kreb's cycle?
Definition
2 pyruvate
Term
what are the products of the Kreb's cycle?
Definition
2 ATP, 2 FADH, 8 NADH, 6 CO2
Term
where does the Kreb's cycle take place?
Definition
Prok- cytoplasm; Euk-mitochondrial matrix
Term
what is the pacemaker in the kreb's cycle?
Definition
pyruvate to acetyl CoA
Term
what is the purpose of the ETC?
Definition
generate energy in the form of ATP from NADH and FADH2 (redox reactions)
Term
what is the starting material in the ETC?
Definition
10 NADH, 2 FADH2, and oxygen or other electron acceptor
Term
what are the products of the ETC?
Definition
3 ATP per NADH (30 total), 2 ATP per FADH2 (4 total), and water
Term
what is the purpose of photosynthesis?
Definition
convert light energy to chemical energy
Term
what is the starting material of photosynthesis?
Definition
CO2 and H2O
Term
what are the products of photosynthesis?
Definition
fructose and O2
Term
where does the ETC take place?
Definition
Euk- mitochondrial membrane; Prok-cell membrane
Term
where does photosynthesis take place?
Definition
chloroplasts; light dependent (grana); light independent (stroma)
Term
how do alcoholic and acidic fermentation differ?
Definition
alcoholic yields ethanol or other alcohol and CO2, acidic yields some acid (lactic, acetic, succinic, or formic) but not CO2
Term
what are the four major types of genes and how do they differ?
Definition
structural - encode proteins that play an important role in cell structure; functional- encode proteins that play an important role in cell function; regulatory -encode proteins or RNAs that play an important role in gene expression; RNA - encode RNA that does not become translated into protein
Term
what makes up a nucleotide?
Definition
phosphate, deoxyribose, and nitrogen base
Term
how are nucleotides attached to each other?
Definition
Phophodiester bonds are the one that connect the nucleotides next to each other on the same strand. Weak hydrogen bonds join the two complementary nucleotides and thus the two strands of the DNA together.
Term
Which enzymes are involved in DNA replication and what are their roles?
Definition
helicase- binds to DNA at the origin of replication where it binds to DNA and seperates the starnds; gyrase-proceeds in front of helicase to remove the super coils from the DNA; primase- synthesizes a RNA primer at the 3 prime ends of the template DNA; DNA polymerase- attaches at the site of the primer, can remove RNA primers and replace with DNA primers, can also proofread for errors; ligase- links Okazaki fragments
Term
In what direction is the template strand read? which direct is it made?
Definition
read 5 to 3, made 3 to 5
Term
How do the terms semiconservative, replication fork, leading strand, lagging strand and Okazaki fragment relate to DNA replication?
Definition
semiconservative- two DNA molecules at end of replication consist of one starnd from old DNA molecule and one starnd of newly sythensized DNA; replication fork- where replication is occuring; leading strand- strand that is replicated continuously; lagging strand (Okazaki fragments)- strand that is synthesized in short fragments
Term
What is the major structural feature of the origin of replication?
Definition
high concetration of adenine and thymine which is easier to break because it only had two H bonds
Term
What are the differences between RNA and DNA?
Definition
DNA is double stranded, has a helix, has thymine, deoxyribose, and is super coiled, while RNA is single stranded, has a helix, has uracil, ribose, can bind to itself to form complex secondary and tertiary structures, and is transcribed from DNA
Term
describe different types of RNA
Definition
mRNA- complementary copy of a gene translated by ribosomes to synthesize proteins; tRNA- recognizes a codon of mRNA and transfers the apporopriate amino acid to the growing peptide chain during translation; rRNA- forms complex 3D structures and provides structure and function to the ribosomal subunits; regulatory RNA- regulate gene expression by interacting with DNA or RNA; primer RNA- created by ligase to help in initiation of DNA replication; ribozymes- RNA enzymes that remove the introns from eukaryotic pre mRNA
Term
Which enzymes are involved in transcription and what are their roles?
Definition
RNA polymerase- adds nucleotides to grwoing mRNA strand; topoisomerase- relieves supercoils ahead of polymerase
Term
In transcription, what direction is the template strand read? which direction is the mRNA strand generated?
Definition
3 to 5; 5 to 3
Term
Explain what redundancy (in the context of translation) means and why it exists.
Definition
a single amino acid can be coded for by multiple codons
Term
What is unique about the first tRNA used in translation
Definition
it enters at the P site, while others enter at the A site
Term
What are the differences between prokaryotic and eukaryotic mRNA?
Definition
In Euk, each mRNA encodes a single protein and the mRNA requires additional processing before translation, whil ein prok, each mRNA may encode for several proteins and does not require additional processing
Term
Describe how an inducible operon functions.
Definition
Term
What are the two major causes of mutation and how do they differ?
Definition
spontaneous- random change due to error in mutation; induced- result from expose to a physical or chemical agent that damages DNA
Term
In what ways can mutagens cause DNA damage?
Definition
insert across both strands of DNA causing distortion in DNA shape; insert durign replication to replace a normal nucleotide from inserting; cause strand breaks; can create bonds between adjacnt pyridimines
Term
what is a point mutation?
Definition
addition, deletion, or substitution of a single base
Term
what is a missense mutation?
Definition
a change in DNA sequence that causes a change in the amino acid coded for during translation
Term
what is a nonsense mutation?
Definition
changes a normal codon to a stop codon causing premature termination of translation
Term
what is a silent muatation?
Definition
a change in base sequence that does not alter the amino acid sequence of the protein
Term
what is a frame shift mutation?
Definition
insertion or deletion of a base which will cause the reading frame of the DNA to change; insertion in multiples of three do not result in a frame shift
Term
What are the three major mechanisms of DNA damage repair? How/when is each used?
Definition
mismatch repair- replaces a single mismatch base during replication; nucleotide excision repair- replaces a fragment of DNA at any point during a cell's lifetime; base excision repair- replaces a single nucleotide base at any time in a cell's lifetime
Term
What test is used to determine whether a compound is mutagenic? If a compound is mutagenic, what will its effect be on growth of cells in this test?
Definition
AMES test; more cells will grow
Term
What two factors are most important for determining the amount of microbial death caused by a microbicidal agent?
Definition
concentration and time
Term
What are the common cellular targets of microbicidal agents?
Definition
cell wall, cell membrane, cellular synthetic process, specific proteins or enzymes
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