• Shuffle
    Toggle On
    Toggle Off
  • Alphabetize
    Toggle On
    Toggle Off
  • Front First
    Toggle On
    Toggle Off
  • Both Sides
    Toggle On
    Toggle Off
  • Read
    Toggle On
    Toggle Off
Reading...
Front

Card Range To Study

through

image

Play button

image

Play button

image

Progress

1/57

Click to flip

Use LEFT and RIGHT arrow keys to navigate between flashcards;

Use UP and DOWN arrow keys to flip the card;

H to show hint;

A reads text to speech;

57 Cards in this Set

  • Front
  • Back
What are the stop codons?
UAA, UAG, UGA
what is the start codon?
AUG
There are six different codons for...
Leu, Arg, Ser
There are only one codon for...
Trp, Met
Pairing combinations with the wobble concept:

5' anticodon G can pair with ___ or ___ in the 3' base in CODON

5' anticodon base U can pair with ___ or ___ in the 3' base in codon

in tRNA, 5' base I (ionosine) can base pair with ___, ___, or ___.
U, C

A, G

A, U, C
How many hydrogen bonds are in wobble base pairing?
2
Wobble allows the cell to have ______ tRNAs. It only occurs in the ____ base of the 3' mRNA or the first base in 5' tRNA for the base ___.
fewer, last, ionosine
Why is the base at the 5' end of the anti-codon (tRNA) allowed to wobble base pair?
There is a large flexible bend in the RNA near that position.
Suppresses the effect of an earlier mutation within the same gene

A second missense mutation in the same gene can bring back biological activity if it somehow restores the original configuration around the functional part of the molecule.
intragenic suppressor mutation
supresses the effect of an earlier mutation in another gene


review slide 9
intergenic suppressor mutation
Mitochondrial genetic code:

Only ___ tRNAs are needed instead of the normal 32. This is because ___ can base pair with all 4 nucleotides in the mRNA.
22, U
Stop codons for the mitochondrial genetic code:
UAA, UAG, AGA, AGG

AGA AND AGG are not arginine codons (as the usual) but specify chain termination. In fruit fly mtochondria, these codons encode for serine.
Mitochondria code:

Internal methionine is encoded by both ___ and ___.
AUG AND AUA
how was the genetic code cracked?
Initial studies used the polynucleotide phosphorylase reaction to make homopolymers of poly-A, poly-C, and poly-U

(poly-G folded back on itself and could not be translated)
Preparing oligoribonucleotides from synthesized DNA led to what?
more codon assignments
Activators that stimulate this kind of promoter work by triggering a con- formational change in either RNA polymerase or DNA; that is, they interact with the stable closed complex and induce a conformational change that causes transition to the open complex (Fig. 18-2b). This mechanism is an example of _______________ (2).
allosteric activation
DNA ______________ fascilitates protein interaction from distant site. ~30-200 bases away. ex: activator protein needs to come in contact with RNA polymerase.
bending
Lac genes are expressed at high levels only when ________ is available, and ________—the preferred energy source—is not.
lactose, glucose
In the lac operon, what activates transcription and what binds to the operator?
CAP activates transcription and Lac repressor binds the operator
The lac operator is symmetric with two _________ sites on each end and a __:__ in the middle.
Half site, G:C
CAP and Lac repressor bind DNA using the common structural motif called
helix-turn-helix
The bacteriophage lambda repressor protein is an example of what motif
helix-turn-helix
Activation of the lac promoter by CAP.

When CAP binds to the CAP site on the mRNA, it is recognized by the _____ of the _____ subunits of RNA polymerase.

This helps and guides RNA polymerase to bind to the promoter.
CTD, alpha,
_________ ACTIVATES CAP.

_________ INACTIVATES CAP by decreasing cAMP.
cAMP, Glucose
Whenever glucose and lactose is present, there is a ________ level of transcription.
basal
When there is glucose but no lactose, there is ______ transcription.
no
When there is no glucose but high lactose, there is an ___________ level of transcription and _____ levels of cAMP.
activated, high
What bacteriophage uses different sigma factors for its lytic life cycle when infecting Baccilus subtillus?
SPO1.
EARLY MIDDLE AND LATE GENES are regulated by SPO1 by transcribing a ______________ of ______________ factors.
cascade, sigma
NtrC and MerR are transcription activators that function
by ____________ instead of recruitment.

They bind the promoter
after RNA polymerase and induce the ____conformation.
allostery, open
_______ is an ATPase. What kind of genes does it transcribe?
NtrC, used to transcribe genes involved in nitrogen metabolism.
NtrC recruit the _____ protein that ______ DNA to help with transcription activation.
IHF, bends
What kind of genes do MerR transcribe?
Transcribe genes involved in mercury resistance.
What does MerR do to the DNA?
it twist it to align the -10 and -35 sequences.
The araBAD operon is controlled by two activators, what are they?
AraC and CAP
In the absence of the inducer ______________, AraC binds to ___ and ____ on the mRNA. AraC then dimerize and a ______ is formed with the mRNA. This _______________ transcription.
Arabinose, I1, araO2

loop, inhibits
When arabinose is present, arabinose binds to ______ which binds to two sites on the mRNA: ____ and ____. This _______________ transcripion.
AraC, i1, i2, stimulates
In the control of gene expression in bacteriophage lambda, the lambda repressor when bound to the lambda genome, induces what kind of growth?
lysogenic
Bacteriophage lambda has a _____kb genome with ______ genes.

There are _____ operator sites in the genome that can be bound by ____ and _____ proteins.
50, 50

cI, cro
The ___ protein is a lambda repressor that can activate or repress. ____ protein can only repress.
cI, cro
PRM (promoter for repressor maintenance) transcribes only the __ gene.
cI
PR and PL are _______ promoters; that is, they bind RNA polymerase efficiently and direct transcription without help from an ________.

PRM, in contrast, is a ______ promoter and only directs efficient transcription when an activator is bound just upstream.
strong, activator, weak
Lytic growth proceeds when PL and PR remain switched ____ while PRM is kept ____.

Lysogenic growth, in con- trast, is a consequence of PL and PR being switched ___ and PRM switched ___.
on, off


off, on
cl repressor binds ____ 10 fold better than ____. cro binds ____ best.
OR1, OR2, OR3
Lambda repressor binds DNA ___________ and as a ________.
cooperatively, dimer
The amino (N) domain of the repressor contains two regions, what are they...
DNA binding region, and activating region
the sites on the carboxyl (C) domain of the repressor has two regions...
dimer region and tetramer region
During DNA damage, ______ is activated. In addition to stimulating homologous
Recombination, ______ stimulates proteolytic autocleavage of certain proteins
including _____ involved in DNA repair and also the ___________ repressor.

This removes the
___-terminal domain of repressor, so dimerization and cooperativity are lost.

This prevents binding to OR1 and OR2. This allows activation of ___ and ___, which stimulates lytic growth!
RecA, RecA, LexA, lambda, C, PR, PL
The repressor bound to OR1 AND OR2 turns of transcription from _____ The repressor bound at OR2 contacts the _______________(2) at PRM, which activates the expression of the ___ repressor. This activity stimulates the ______________________ cycle. This is also an example of _____________ regulation as the repressor stimulates stranscription of it own protein
PR, RNA polymerase, cI, lysogeny, positive
OR3 lies within P__. Cro, when bound there, because it has highest affinity for it, repress transcription of ___. It makes more of its Cro gene (positive regulation.
This stimulates the __________cycle.
RM, cI, Lytic
Interaction of repressors at OR and OL allow ________ regulation.
negative
This negative autoregulation works as follows:

PRM being activated by repressor cI (at OR2) to make more repressor. But if the concentration gets too high, repressor will bind to _____ as well and repress____.

cI starts blocking its own promoter when levels get to high
OR3, PRM
Interaction between the repressors on OL1, 2, 3 AND OR1, 2, 3 form an __________.
octamer
cII is on the right of cI and is transcribed from ___; cIII, on the left of cI, is transcribed from ___.
PR, PL
Like the l repressor, the CII protein is a ________________(2). It binds to a site _________ of a promoter called _____ (for repressor establishment) and stimulates transcription of the ____ (repressor) gene from that promoter.


Thus, the repressor gene (cI) can be transcribed from two different promoters (PRE and PRM)
TRANSCRIPTIONAL ACTIVATOR, UPTREAM, PRE, cI.
CII bind PRE and initially stimulates
transcription of the cI (repressor) gene from that promoter, which
favors _______ growth.

But the cro protein that stimulates ___________
growth is transcribed from the PR promoter initially.
lysogenic, lytic
The number of phage particles that enters the bacterium
determines if lytic or lysogenic growth occurs.

If the average
number of phage is _______________ per cell than lytic growth is
favored. It the number is _____________ lysogenic growth is
favored.
one or fewer,
two or more