Shared Flashcard Set

Details

Test 2
Study Guide for UIW Foglesong Microbiology
134
Microbiology
Undergraduate 2
03/06/2012

Additional Microbiology Flashcards

 


 

Cards

Term
Chemotrophs
Definition
use chemical substances as source of energy
Term
phototrophs
Definition
use light as a source of energy
Term
autotrophs
Definition
use CO2 as sole source of carbon
Term
heterotrophs
Definition
use organic compounds as source of carbon
Term
organotrophs
Definition
use organic compounds as source of carbons
Term
lithotrophs
Definition
use inorganic compounds as source of electrons
Term
bacteria
Definition
play critical roles in the nitrogen cycle
Term
nitrogen fixation
Definition
conversion of N2 from the air into NH3
Term
ATP
Definition
storage molecule for chemical energy in all cells
Term
catabolism
Definition
biodegradation
Term
anabolism
Definition
biosynthesis
Term
The energy produced in ________ provides the energy needed for ________.
Definition
catabolism, anabolism
Term
ATP is hydrolyzed to
Definition
ADP + Pi + energy in a reversible reaction
Term
Endergonic reactions
Definition
would not occur in living cells, but can be effectively promoted by coupling them to ATP hydrolysis
Term
oxidation
Definition
the loss of electrions
Term
reduction
Definition
gain of electrons
Term
redox reactions
Definition
oxidation-reduction reactions in which electrons are transferred from one substance (that becomes oxidized) to another substance that be comes reduced
Term
biological redox reactions
Definition
two electrons and two hydrogen ions are transferred simultaneously
Term
Electron transport chains
Definition
proteins that are imbedded in membranes that transfer electrons and hydrogen ions in such a way that a pH gradient is generated across the membrane.
Term
chemiosmosis
Definition
This force drives the synthesis of ATP catalyzed by the enzyme ATP synthase when hydrogen ions pass through the the enzyme
Term
enzymes
Definition
biological catalysts; most are proteins
Term
catalytic RNAs
Definition
robozymes
Term
active site of the enzyme
Definition
the place on it where the substrate binds
Term
active site of the enzyme
Definition
the place on it where the substrate binds
Term
competitive inhibitors
Definition
compounds that compete for the binding of substrate to the enzyme
Term
allosteric site on an enzyme
Definition
another site to which a noncompetitive inhibitor or activator can bind thereby affecting the activity of the enzyme
Term
feedback inhibition
Definition
in some anabolic (biosynthetic) pathways the final product of the pathway acts as a noncompetitive inhibitor of the first enzyme in the pathway
Term
enzymes
Definition
lower the activation energy needed for catalysis
Term
the activity of an enzyme is influenced by
Definition
influenced by pH, temperature and the concentration of substrate
Term
glycolysis
Definition
the cleavage of glucose into two three-carbon compounds
Term
the Kreb's (TCA) cycle
Definition
converts acetyl-CoA into 2 CO2
Term
substrate level phoshorylation
Definition
results in 2ATP/glucose in glycolysis and 2GTP=2ATP in the Kreb's cycle
Term
oxidative phosphorylation
Definition
converts NADH and FADH2 into ATP by chemiosmosis
Term
the maximum possible energy yield
Definition
for one molecule of glucose in aerobic respiration is 38ATP/glucose, but the actual yield is usually 30-32 ATP/glucose
Term
respiration
Definition
a series of redox reactions in which an inorganic substance is the final electron acceptor. In aerobic respiration that substance is O2
Term
fermentation
Definition
a series of redox reactions in which an organic substance is the the final electron acceptor, usually a small organic acid or alcohol. A number of fermentative microbes are commerically important such as bakers' and brewers; yeast (S. cerevisiae) the yield of ATP from fermentation is 2ATP/glucose
Term
lipids and proteins
Definition
can be catabolized to yield energy
Term
metabolism
Definition
extensively integrated so that the same or similar pathways can be used for production of energy or production of carbon chains for biosynthesis
Term
photosynthesis
Definition
results in carbon fixation powered by ATP produced from the absorption of light by chlorophylls organized into photosystems. These processes occur in chloroplasts in eukaryotes and in the plasma membranes of prokaryotes
Term
Photosystem I
Definition
has cyclic electron flow and doesn't produce oxygen
Term
Photosystem II
Definition
has noncyclic electron flow and does produce oxygen.
Term
carbon fixation
Definition
CO2 added to carbohydrate
Term
_________ are __________ into polymers in anabolism of macromolecules
Definition
monomers are polymerized. these requireenergy. most of the ATP used by cells is used in the synthesis of proteins
Term
amino acids form
Definition
proteins
Term
nucleotides form
Definition
nucleic acids
Term
monosaccharides form
Definition
polysaccharides
Term
DNA
Definition
the genetic material in all cells and many viruses
Term
Griffith's transformation
Definition
this experiment was very strong evidence that DNA is the genetic material
Term
vertical
Definition
transmission of DNA that occurs in cell division
Term
horizontal
Definition
transmission of DNA occurs within a generation
Term
duplex molecule
Definition
consistin of two strands (polymers of nucleotides attached by phosphodiester bonds. Has a 5'-->3' polarity and is antiparallel with respect to the polarity of the two strands
Term
the four bases in DNA
Definition
ACGT and form base pairs AT and GC
Term
where sequence-specific DNA binding proteins bind
Definition
the major groove of the double helix of duplex DNA
Term
DNA replication
Definition
involves separation of the two strands of parental DNA and their copying as templates resulting in the synthesis of two new strands of daughter DNA
Term
polymerase
Definition
the main enzyme in DNA replication
Term
primase and ligase
Definition
important enzymes in DNA replication
Term
discontinuous, continuous
Definition
DNA synthesis is ____ on the lagging strand and _____ on the leading strand
Term
one, many
Definition
there is ____ origin on circular DNAS and there are ____ on large linear chromosomal DNAs
Term
Nucleic acid synthesis
Definition
proceeds in the 5'-->3' direction
Term
telomeres
Definition
repeated DNAs on both ends of eukaryotic chromosomes. They are generated by the action of telomerase, an enzyme that copies RNA in making DNA
Term
transcription
Definition
the synthesis of RNA complementary to the template strand of DNA in the gene
Term
RNA polymerase
Definition
the enzyme that catalyzes the polymerization of ribonucleotides into RNA. it binds to a sequence of DNA called the promoter. There is one RNA polymerase in E. coli that synthesizes mRNA, rRNA and tRNA. In eukaryotes there is a separate RNA polymerase for each of these
Term
polycistronic mRNAs
Definition
In bacteria, related genes are clustered together and transcribed into _________ that are then translated into several proteins
Term
monocistronic RNAs
Definition
In eukaryotes genes are transcribed individually into ______ that are translated into one protein
Term
exons
Definition
Eukaryotic genes have coding sequences
Term
introns
Definition
non coding sequences in eukaryotic genes
Term
heterogeneous nuclear RNA (hnRNA)
Definition
the first product of transcription in eukaryotes that must be spliced to remove introns
Term
sliceosomes
Definition
complexes of small nuclear RNAs and proteins that perform the splicing
Term
genetic code
Definition
a triplet code that is nearly universal in biology. three nucleotides in mRNA encode one amino acid in the protein product of the gene. There are 20 common amino acids in proteins and 61 codons
Term
degenerate
Definition
the genetic code is said to be _______, more than one codon per amino acid
Term
AUG
Definition
the start codon
Term
UAA UAG and UGA
Definition
stop codons
Term
transfer RNAS
Definition
have an anticodon that matches the sequence in the codon
Term
aminoacyl-tRNA sythetases
Definition
amino acids are attached to tRNAS by this (requires ATP)
Term
peptidyl transferase
Definition
activity in protein synthesis is 23S rRNA in bacteria 28S rRNA in eukaryotes.
Term
catalytic RNAs
Definition
catalyze the formation of peptide bonds between amino acids
Term
protein snthesis
Definition
occurs on the ribosome 70S in bacteria 80S in eukaryotes
Term
protein initiation factors, elongation factors as well as GTP
Definition
required for protein synthesis
Term
protein release factors
Definition
bind to stop codons and mediate termination pfprotein synthesis
Term
protein folding
Definition
may occur spontaneously or require specific proteins (chaperones)
Term
gene expression
Definition
regulated at the level of transcription by proteins binding to specific sequences of DNA
Term
regulation
Definition
occurs at the level of translation as well, epsecially in eukaryotes. Also, mRNA splicing can be regulated
Term
constitutive genes
Definition
always expressed
Term
inducible genes
Definition
function in catabolism are usually not expressed, but they can be turned on
Term
repressible genes
Definition
function in anabolism are usualy expressed but they can be turned of
Term
the lac operon
Definition
regulated by a repressor that binds to an operated. When the repressor is bound transcription is blocked
Term
lactose
Definition
inducer, when it is present, it binds to the repressor and causes it to change shape so that it can't bind to DNA; transcritpion then occurs
Term
trp operon
Definition
regulated by a repressor that binds to an operator
Term
tryptophan
Definition
corepressor, when it is present, it binds to the repressor and activates it so that it binds to the operateor sequence of DNA
Term
negative regulation
Definition
inhibition of transcription
Term
positive regulation
Definition
stimulation of transcription
Term
lac operon
Definition
exhibits both negative and positive regulation; negative by the repressor and positive by the CAP-cAMP
Term
adenlyl cyclase
Definition
when glucose levels are low _______ converts ATP in to cyclic AMP (cAMP) + PPI. cAMP binds to the catabolite activator protein (CAP) to form a functional complex that binds to DNA and stimulates the binding of RNA polymerase to its promoter
Term
siRNAs (small nuclear RNAs)
Definition
bind to mRNAs and cause them to be degraded by a nuclease (dicer) this eliminates the mRNAs from being translated into proteins
Term
novel sequences
Definition
DNA sequences can recombine to yield these
Term
mutation
Definition
achange int he sequence of nucleotides in DNA
Term
mutagens
Definition
chemicals that cause mutations
Term
UV or x-rays
Definition
electromagnetic radiation
Term
point mutations
Definition
changes in on base pair in the DNA
Term
missense mutations
Definition
change a codon into a codon for another amino acid
Term
nonsense mutations
Definition
change a codon for an amino acid into a stop codon
Term
silent mutations
Definition
change a codon for an amino acid into another codon for teh same amino acid
Term
thymine-thymine dimers
Definition
occur when DNA obseorbs UV light
Term
repair enzymes
Definition
correct damage to DNA
Term
excision repair
Definition
for any DNA squence
Term
mismatch repair
Definition
for newly replicated DNA only
Term
excision repair and mismatch repair
Definition
involve removal of damaged DNA segment, polymerization of nucleotides to fill in the gap and DNA ligation
Term
carcinogens
Definition
chemicals that cause cancer. They can be assayed as mutagens in the AMes test that measures the frequency of reversion of a his- mutation to the wild type his+
Term
auxotroph
Definition
nutritional mutant
Term
homologous recombination
Definition
occurs between relatied DNA sequences
Term
site-specific recombination
Definition
occurs at specific sites
Term
plasmids
Definition
small circular DNAs with their own origin of DNA replication. They replicate independently of the bacterial chromosomal DNA. The F factor is a plasmid that is required for conjugation. Donor E. coli are F+ and recipients are F-
Term
F Factor
Definition
this itself is transfered. it can integrate into the bacterial chromosomal resulting in a high frequency of recombination cell. the high frequency recombination cell can cross with an F- cell; chromosomal genes are transferred
Term
transposon
Definition
a mobile sequence of DNA some transposons harbor genes for drug resistance
Term
transformation
Definition
the uptake and integration of DNA this occurs at high frequencies in bacteria
Term
transduction
Definition
the uptake and incorporation of DNA mediated by a virus
Term
generalized transduction
Definition
the encapsidation of a piece of bacterial DNA into a virus particle
Term
recombinant DNA
Definition
DNA from two sources that is spliced together
Term
restriction enzymes
Definition
cut DNA at specific sequences (palindromes) many different restriction enzymes have been isolated from different microbes
Term
vector
Definition
a sequence of DNA that can be used for the formation of recombinant DNA.
Term
cloning vectors
Definition
for production of DNA inserts
Term
expression vectors
Definition
production of the protein product of the gene
Term
complementary DNA (cDNA)
Definition
is produced from mRNA by reverse transcriptase
Term
selectable marker
Definition
a gene for resistance to an antibiotic; such a gene can be used to ensure that transformed bacteria contain recombinant DNA desire
Term
libraries
Definition
series of cloned DNAs
Term
DNA fragments
Definition
can be separated by size by agarose gel electrophoresis
Term
Southern blot
Definition
combines the separation of DNa by size with the detection of specific DNA sequences by hybridization
Term
hybridization
Definition
allowing mixed duplexes to form between a test DNA or probe and the DNA being studied
Term
polymerase chain reaction
Definition
a way to amplify DNA. it uses oligonucleotide primers and Taq DNA polymerase (thermostable) in a thermocycler to produce many copies of DNA in a test tube
Term
Sanger method
Definition
DNA sequence method uses dideoxynucleotides as chain terminators. The results are analyzed by polyacrylamide gell electrophoresis. This process has ben automated. Newer sequenciing thenologies are much more powerful. Tens of billions of nucleotides of DNA sequences are availableon public data bases
Term
genome
Definition
consists of all genes in an organism
Term
microarrays
Definition
the expression of many genes can be analyzed simultaneously by using this
Term
proteome
Definition
represents all proteins in an organism. They can be anaylzed using two-dimensional gell electrophoresis
Supporting users have an ad free experience!