Exam 2 Review Flashcards
What are formed on the lagging strand during DNA synthesis?
Okazaki fragments
An example of correct nucleotide pairing is..
A and T, C and G. Thymine is replaced by Uracil in RNA
The two strands of the DNA double helix are held together by
hydrogen bonds between nucleotide bases.
DNA replication is started with a(n) __________, which, in most cases, in vivo is a short stretch of ___________.
primer
RNA
tRNA is released from the ribosome at the ________ site.
E
The codon on the _______ matches with the anticodon on the ________ to direct the addition of the correct amino acid to the growing polypeptide chain.
mRNA
tRNA
The structure and function of a protein are determined by its _________ sequence.
amino acid
GTP provides energy for
translation
DNA-binding proteins interact predominantly within which portion of a double-stranded DNA helix?
major groove
In the process of transcription, promoters are specific sequences of _______ that are recognized by _________
DNA
sigma factors
Transfer RNA (tRNA) molecules
function to transfer the correct amino acids to the ribosome during translation
Each adenine-thymine base pair has _________ hydrogen bonds, while each guanine-cysteine base pair has ______ hydrogen bond(s).
two
three
An operon is a useful genetic element, because it
allows coordinated expression of multiple related genes in prokaryotes
The flow of biological information begins with
DNA replication
In Bacteria, a chromosome can be distinguished from a plasmid, because a chromosome is a genetic element that
encodes for essential functional genes
When arginine is added to a culture already growing exponentially in a medium without arginine, what occurs?
Growth continues, but the production of enzymes required for the synthesis of arginine ceases.
Which type of regulator(s) specifically binds to operator regions of DNA?
Repressors
The lac operon is an example of __________ control in which the presence of an _________ is required for transcription to occur.
negative
inducer
Enzyme induction occurs
when the substrate is present
In negative control of transcription by the lac operon, how does the presence of an inducer affect transcription?
The inducer prevents the repressor from binding to the operator
The function of a kinase is
phosphorylation
The promoters of positively controlled operons require activator proteins because
the promoters bind RNA polymerase weakly and utilize activator proteins to help RNA polymerase recognize the promoter
_______ pathways typically rely on _______ proteins to inhibit mRNA synthesis.
anabolic
repressor
When more than one operon is under the control of a single regulatory protein, the operons are collectively called a(n)
regulon
In catabolic repression, cells always use the least abundant carbon source first. T/F?
False
A mutant that has a nutritional requirement for growth is an example of a(n)
auxotroph
Consider a mutation in which the change is from UAC to UAU. Both codons specify the amino acid tyrosine. Which type of point mutation is this?
silent mutation
Which process
allows genetic material to be transferred from a virus-like particle that lacks genes for its own replication?
Gene transfer through a gene transfer agent
The mutagens 2-aminopurine and 5-bromouracil are examples of
nucleotide base analogs
What method(s) may introduce foreign DNA into a recipient?
Transformation, transduction, and conjugation
The uptake of free DNA from the environment is referred to as _________, while the transfer of DNA with cell-to-cell contact is known as _________
transformation
conjugation
Lysogeny probably carries a strong selective advantage for the host cell because it _____
confers resistance to infection by viruses of the same type
Hfr strains of E. coli
have an integrated F factor
A deleterious mutation in recA results in
a decrease in homologous recombination
What is most similar to lysogeny?
Hfr state
The SOS regulatory system is activated by
DNA damage
True about competence
It is required for transformation
it cannot occur naturally in bacteria
it requires special proteins such as a cell wall autolysin
