Exam 3 Flashcards
(225 cards)
1
Q
genotype
A
what genetic info u have
2
Q
phenotype
A
what traits you express
3
Q
genetic information flow (central dogma)
A
DNA (nucleic acids) –> RNA (amino acids) –> protein
4
Q
what contains all the info needed to transcribe DNA into mRNA
A
a gene!
5
Q
translation of start vs stop codon
A
- start codon is translated and found within the transcribed region
- stop codon is not translated and is found outside the amino acid sequence (not encoded within the protein)
6
Q
+1 nucleotide
A
(indicated often with an arrow)
- indicates the transcription start site and first nucleotide to be transcribed
*not necessarily before the AUG start codon
7
Q
coding versus template strand
A
coding 5’ to 3’
template 3’ to 5’
see the codons within the coding strand (look for ATG)
8
Q
what direction is RNA synthesized?
A
5’ to 3’ direction of the strand being built
(antiparallel to its complementary strand of DNA)
TEMPLATE = ANTIPARALLEL
CODING = CODONS
9
Q
gene sequences written/read convention
A
gene sequences are written/read from 5’ to 3’ of the coding strand
*for a given gene, only 1 strand serves as a template
10
Q
different genes have different ______
A
directions of transcription
this is bc different strands of dsDNA are used as the template for different genes (might be coding for one gene but template for another)
11
Q
RNAP binds ______ to the promoter
A
upstream and moves downstream toward the rest of the gene
12
Q
cis and trans elements purpose
A
recruit RNA polymerase to a gene
13
Q
cis elements
A
regions of DNA that are required for gene expression/regulation
*part of the same molecule as the gene(s) they regulate!
14
Q
trans elements
A
diffusible molecules (usually proteins) that bind cis elements
*separate molecules from the genes they regulate!
15
Q
sigma subunit
A
key trans-factor that helps RNAP associate with promoters
in prokaryotes
many subunits functions together as 1 enzyme
16
Q
consense sequences
A
a sequence of DNA having similar structure and function in different organisms.
(same sequence in the same location)
-10 and -35 consensus sequences are found in nearly all bacterial promoters
17
Q
-35 consensus sequence
A
TTGACA
18
Q
-10 consensus sequence
A
TATAAT
19
Q
differences in euk. cis/trans factors (3)
A
1) no sigma subunit
2) different consensus sequences (TATA box most common)
3) additional cis-reg. elements besides promotor (enhancer/silencer) common. Enhancer often required!
20
Q
termination sequence in prokaryotes
A
IS transcribed
21
Q
termination mechanism of transcription
A
hairpin/stem loop
- complementary base pairing with itself
- strong C-G bonds hold structure together causing the stalling of RNAP
- When stalling occurs, the weak AU bonds cannot hold mRNA and DNA complex together
22
Q
Rho protein
A
protein that induces the unwinding of RNA/DNA complex
-transcription termination of prokaryote
23
Q
splicesome
A
snRNA and proteins
- functions in recognizing introns and removing them
- recognizes specific sequences in the DNA that will determine the sites of splicing
- via BPing, the RNA component of splicesome recognizes the splice site sequences
- found in nucleus
24
Q
w/o CAP and Tail, RNA…..
A
would be degraded
25
If the protein were sufficient to catalyze the reaction, then what is the purpose of having RNA complexed?
recognition of the sequences that designate an intron
26
alternative splicing may generate...
2 or more types of mRNA from the same transcript
27
3 steps of translation
initiation, elongation, termination
28
translation initiation
complex of the ribosome, first charged tRNA, mRNA
29
translation elongation
peptide bonds formed as charged tRNAs bring appropriate amino acids
30
translation termination
stop codons signal release factors and complex dissociates (@ A site)
31
Shine-Delgarno sequence
- ribosome binding site
- positions ribosomes by start codon
- found only in prokaryotes
32
ribosomal peptidyl transferase
transfers the peptide in the P site to the amino acid in the A site
33
termination of translation occurs...
when a stop codon is reached and a release factor binds
34
dehydration synthesis reaction
- catalyzed by ribosomes in order to form a peptide (covalent) bond between 2 amino acids
- loss of a water molecule
35
polarity of peptide
- having 2 distinct ends
- polarity of monomer is preserved in the polymer
(direction of coding and template in reference to mRNA)
36
translation builds peptides in what direction?
N to C
amino acid to carboxylic acid
37
open reading frames (ORFs)
indicate regions that could potentially encode for a protein
- sequence of codons within the same reading frame starting with 5'-AUG and ending with STOP-3'
38
mRNAs contain both....
translated and untranslated regions
39
- the transcription initiation site (+1 site) is....
NOT the translation initiation site (AUG)
40
ORF rule of thumb
the longer the ORF, the more likely its a true protein-coding ORF
41
identifying ORFs
use coding strands that look like mRNA
42
steps for locating proteins (6)
1) locate potential start codons (ATGs in any direction if coding strand is unknown)
2) identify the ORFs by finding inframe STOP codons
3) Determine polypeptide length
4) Determine directionality
5) Determine mRNA sequence
6) Translate!
43
tRNAs
translate codons into amino acids
- speak both languages bc can bind to codons that are both complementary and antiparallel
-function is to base pair with the codon on a strand of mRNA during translation.
***ensures that the correct amino acid will be added to the growing polypeptide chain.
44
how many codons are there?
64
45
how many codons encode for amino acids?
61
46
writing conventions for codons and anticodons
5'-codon-3'
3'-anticodon-5'
47
aminoacyl-tRNA synthetase
enzyme that carries out the charging of the tRNA with its specific amino acid
- attaches an a.acid to its tRNA
- highly specific for a given amino acid and for a given tRNA
48
aminoacyl- tRNA product
charged tRNA
49
wobble pairing
allows for a single anticodon of a tRNA to interact with more than one mRNA codon
50
G at the 5' end of the anticodon recognizes...
C or U at the end of mRNA codon
51
the flow of genetic info can vary...
from gene to gene
for the same gene in different contexts
52
why doesnt bacterium transcribe all of its genes all the time?
- metabolize organisms
- bacteria only produce the proteins needed for lactose metabolism when lactose is present
- saves energy and resources only to transcribe/translate when a protein is needed
53
add (+) regulation with
activator
54
remove (-) regulation with
repressor
55
inducible
default state = OFF
- transcription turned ON
56
repressible
default state = ON
- transcription can be turned OFF
57
constitutive
always on
- expression even when there is no lactose around and the operon should be turned off
58
2 ways to induce a gene
1) add activator
2) remove repressor
59
prokaryotes tend to regulate gene expression at the level of...
transcription
60
polycistronic RNAs
mRNAs that code for more than one protein under the control of a single promoter. (share a promotor)
(prokaryotic only)
61
operon
group of prok. genes that share a promoter and get regulated and transcribed as one unit
(energy/resource saver)
62
5 components of the lac operon
Regulatory:
1) promoter (P)
2) operator (O)
Ensures Lac Y/Z expression:
3) LacI
Genes encoding metabolism proteins:
4) LacZ
5) LacY
63
promoter (p)
DNA site where RNA polymerase initially binds
64
operator (o)
the site where the repressor binds
65
LacI
gene that encodes the repressor protein
****gene itself is NOT part of the lac operon
- has its own promoter and its regulated seperately
- still relevant bc protein it encodes regulated the lac operon
66
LacZ
gene that encodes B-galactosidase, an enzyme that breaks down lactose into monosaccharides
67
B-galactosidase
enzyme that breaks down lactose into monosaccharides
68
LacY
gene that encodes permease, an enzyme that makes it easy for lactose to enter the cell
69
permease
an enzyme that makes it easy for lactose to enter the cell
70
it is only beneficial to transcribe lac operon components when...
lactose is present
71
repressor protein can bind to...
allolactose and the operator BUT NOT at the same time
72
Without lactose....
repressor protein binds to operator and RNA poly cannot pass
- transcription DOES NOT occur
73
With lactose...
allolactose binds to repressor protein and changes shape so that it cannot bind to the operator
- transcription DOES occur
74
allolactose will always...
be present under the presence of lactose
75
WT Lac operon is only transcribed when...
lactose is present to inactivate the repressor
INDUCIBLE (default off)
- adding lactose turns on transcription
**induces by removing (-) regulation; stops repressor from binding
76
2 different mutations that could prevent the lac repressor from binding to the operator...
Lac I-
Lac Oc
77
Lac I- mutation
changes the shape of the Lac repressor DNA binding domain
- prevents lac repressor from being made
78
Lac Oc mutation
changes DNA sequence (operator) that Lac repressor recognizes
- prevents lac repressor from binding
- constitutive expression
79
Lac Is mutation
prevents binding of allolactose
- prevents transcription (default OFF)
*** uninduciable transcription
super repressor
80
Lac Z- mutation
produces nonfunctional B-gal protein
- cannot metabolize lactose
- does not prevent transcription
81
Lac Y- mutation
produces a nonfunctional permease protein
- stop the metabolism of lactose as it will not be able to enter the cell without permease.
82
Lac I- and I+ relationship
Lac I- is recessive to Lac I+
- heterozygote is inducible, not constitutive
(Lac I+/I- => merozygote)
83
bacteria (haploid) can become....
partial diploids OR merozygotes by aquiring plasmids
84
repressors cis or trans?
trans (diffuse to operator)
85
I-O+Z+Y+/I+O+Z+Y+ phenotype
inducible
- w/o lactose (still has one I+) so still produces repressor protein and BLOCKS trans.
- w/ lactose, repressors cannot bind and trans. occurs
86
I+O+Z+Y+/I+OcZ+Y+ phenotype
constitutive
*mRNA produced only from the operon with Oc mutation in CIS
- w/o lactose, repressors bind to one operator but not the other (some transcription)
- w/ lactose, all repressors cannot bind to operators (NO transcription)
87
regulatory elements
- controls expression of genes
- directly influences whether RNAP transcribes a gene
88
if lactose metabolism genes are transcribed constitutively...what mutations could have caused such?
- LacI- (repressor doesn't work)
- LacOc (operator no longer binds to repressor)
89
Lac Oc causes constiutive expression only when...
alleles are in cis not trans (on same DNA molecule)
DOMINANT (O+ will falil to rescue the constiutive phenotype)
90
effector lactose induces the lac operon by...
removing (-) regulation
91
effector cAMP induces the lac operon by...
adding (+) regulation
92
e. coli prefers to metabolize...
glucose for carbon energy source
- therefore, beneficial to transcribe lac operon only when glucose is absent
93
CRP
trans-regulatory factor that binds the promoter and helps to recruit RNAP
- w/o CRP, RNAP is inefficient for finding and binding to promoter (trans. levels LOW)
94
cAMP
effector that causes allosteric changes to CRP to allow it to bind to the promoter
95
cAMP levels are ____ when glucose levels are _____
HIGH --- LOW
96
bacterial growth in lactose and glucose
1. metabolizes glucose for low level transcription
2. runs out of glucose, changes gene expression, and plateaus
3. metabolizes lactose instead for higher levels of transcription
97
transcription of the lac operon is at its MAX when...
lactose is present and glucose is absent
98
no glucose or lactose
no transcription
99
both lactose and glucose present
medium transcription
100
lactose absent and glucose present
no transcription
101
catabolic pathway operons
inducible (break down)
102
anabolic pathway operons
repressible (build up)
103
why are anabolic and catabolic pathways repressible and inducible respectively?
anabolic = repressible
- waste to make enzymes needed to build something that is already abundant (auto ON)
catabolic = inducible
- waste to make enzymes needed to break something down that is not present (auto OFF)
104
trp operon
controls the expression of tryptophan synthesis of genes (anabolic)
contains:
- trp promoter
- trp operator
- repressor protein binding to operator (trpR)
- structural genes for tryptophan biosynthesis (trpE/B/C/D/A)
105
when tryptophan binds to trp repressor protein bound to operator...
transcription does not occur (operon is turned off)
- repressible (auto ON)
- adds (-) regulation)
- anabolic operon repressed in the presence of their metabolic end products (turned off when end product formed)
106
7 types of gene expression
Regulation of:
1. chromatin remodeling
2. transcription
-------- post-translational
3. splicing and processing
4. transport (out of cell)
5. degradation of mRNA
6. translational
7. protein modification
107
all cells in an organism have....
the same DNA
- same genes and same cis elements
- BUT may express different trans elements
108
what do differences in the expression of trans elements come from?
asymmetries of trans factors are established early in development, sometimes before fertilization
109
the same gene in different cell types will have...
the exact same DNA (promoter and all regulatory elements)
110
2 different genes in the same cell types will...
not be identical (different reg. elements)
111
each cell is a different environment...
has different TFs that may or may not bind to cis reg. elements of different genes
112
a gene will be off unless
cis-elements are accessible to bind to TF (by changes in chromatin structure)
- therefore can turn any gene on
113
TFs cannot interact with....
cis-elements that are packed into inaccessible chromatin
114
euchromatin
loosely packed
open
accessible
transcription ON
115
heterochromatin
condensed
closed
inaccessible
transcription OFF
116
chromatin accessibility can be regulated in 3 ways:
1. histone modifications
2. DNA methylation
3. Nucleosome sliding/reorganization
117
histone modifications
- Acetylation increases accessibility
--- reduces (+) charge of histones by adding (-) charge to make less affinitive to (-)DNA
118
methylation, ubiquitination, phosphorylation have....
variable effects on accessiblity
119
DNA methylation
- usually cytosine in eukaryotes
- can result in more or less transcription unlike histone methylation
*most often associated with heterochromatin formation, decreased transcription, and gene silencing
120
nucleosome
- DNA and histone
Nucleosomes at the promoters of genes regulate the accessibility of the transcription machinery to DNA,
121
interaction of cis and trans factors in a cell determines...
if/how a gene is transcribed
1) basal factors
2) TFs binding to enhancers/silencers
3) Tfs+cofactors
122
basal factors
bind to promoters to recruit RNA poly to the gene
LOW LEVEL TRANSCRIPTION if only factor bound to DNA
123
specific TFs bind to .....
enhancers or silencers
increases rate of transcription in addition to basal factors
124
Physical interaction with the poly and TFs + their co-factors will...
increase or decrease the rate of transcription
125
promoters are always...
directly upstream of the transcribed portion of the gene
126
if u change orientation or location of promoter....
gene is NOT transcribed
127
enhancers are always...
on the same chromosome (in cis) to genes they regulate
- nearby but can be far away (few hundred/thousand bp away on coding gene)
128
if u change orientation or location of enhancer....
cis/trans factors can usually still complex and function normally
129
silencer
type of enhancer that decreases transcription by binding to repressor proteins
130
context-specific cis elements
context-specific if they interact with TFs present/active only in those specific contexts
(cell type, envt.)
131
commonly responsbile for context-specific regulation of euk. genes?
enhancers/silencers
132
can contain consensus sequences which interact with context-specific TFs?
promoters
133
Hox genes
encode TFs that specify the formation of specific parts of the body
134
ex/ front leg hox gene
front leg hox gene produces... front leg hox protein (TF) that binds....to cis regulatory elements on gene
135
if body part in wrong spot....
body part will still be found noramlly in correct location
136
having a head promoter on a leg hox gene (leg hox TF protein coding region)...
results in leg on head
--- gene encodes for wherever the promoter directs expression to (INDUCTION)
137
loss of function experiment clues for where a gene is expressed
- function in development of body part
- when during development/adulthood?
138
flies lacking eyes
eyeless gene
ey-/ey-
139
transgenic construct that shows which cells express the eyeless protein from embryo to adult stage
design: link eyeless cis elements to reporter gene (GFP)
methods: add this hybrid transgene to normal early embryo
results: look for GFP expression as flyes develop
- indicates where eyeless is being expressed and functioning!
140
GFP
green fluorescent protein
- reporter gene we can see in living tissues
141
transgene
a gene that has been transferred naturally, or by any of a number of genetic engineering techniques, from one organism to another.
can change phenotypes !!
142
promoters
signal RNA poly to begin transcription
- gene sequences near the start site attract RNAP
143
initiation of transcription
- RNA poly binds to dsDNA at promoter
- RNAP unwinds dsDNA to expose unpaired bases on template strand
144
elongation of transcription
- sigma subunit is released and RNAP looses its affinity for promoter and gains affiinity to DNA
- mRNA extended 5' to 3' antiparallel to template strand
145
termination of transcription
terminator RNA sequences signal the end of transcription
- forms hairpin loops
- releases both RNA polymerase and mRNA chain from DNA
146
hairpin loops
ssRNA folds back on itself and comp. base pairs with C/G's
147
primary transcript
single strand of RNA resulting from transcription
148
prok. vs euk. primary transcripts
P: primary transcript is the mRNA used for synthesis
E: primary transcript undergoes RNA processing before protein synthesis
149
methylated cap
structure at the 5' end of euk. mRNA formed by capping enzyme and methyl transferase
*efficient translation of mRNA into protein
150
poly A tail
structure at the 3' end of euk. mRNA consisting of 100-200 A residue
- stabilizes the mRNA
- uses ribonuclease and poly-A-polymerase
*efficient translation initiation
151
5' and 3' untranslated regions (UTRs)
sequences located just after the methylated cap and before poly-A-tial
- encoded by exons and don't include codons
152
RNA splicing
deletes introns in euk. pre-mRNA and joins together adjacent exons to form mature mRNA
153
spliceosome
a complex intranuclear machine that performs RNA splicing
contains small nuclear ribonucleoproteins (snRNPS)
154
transfer RNA (tRNA)
small RNA adapter molecule that through complementary base pairing with codons in mRNA and places a specific amino acid at the correct position in a growing polypeptide chain at ribosome
*each tRNA carries 1 amino acid
155
anticodon
3 nucleotides in tRNA molecules that recognize codons on mRNA by comp. BPing and wobble
*runs antiparallel to codon
156
aminoacyl-tRNA synthetases
enzymes that catalyze the attachment of tRNAs to their corresponding amino acids, forming charged tRNAs
157
charged tRNA
tRNA molecule to which the corresponding amino acid has been attached by aminoacyl-tRNA synthetase
- bond between tRNA and AA generates energy for peptide bond formation
158
wobble
1 tRNA == more than one codon
- 5' end of anti-codon "wobbles" and can pair with multiple bases at 3' of codon
159
peptidyl transferase
the enzymatic activity of the ribosome responsible for forming peptide bonds between successive amino acids
160
aminoacyl (A) site
site on a ribosome to which a charged tRNA first binds
161
peptidyl (P) site
site on a ribosome to which the initiating tRNA first binds and the tRNAs carrying the growing polypeptide are located during elongation
162
exit (E) site
occupied by tRNAs during period just after their disconnection from a.acids by action of peptidyl transferase and before release from ribosomes
163
initiation codon
first codon to be translated and AUG at 5' end of polypeptide
164
Initiation
1st phase of translation for addition of amino acids during elongation
165
ribosome binding site
region on prokaryotic mRNAs containing initiation codon and Shine-Delgarno box
--- ribosomes bind with site to begin translation
166
Shine-Delgarno box
sequence of 6 nucleotides (5'-AGGAGG-3') in pro. mRNA that is one of two elements constituting a ribosome binding site
167
promoters
signal RNA poly to begin transcription
168
TSP initiation
- RNA poly binds to the dsDNA at gene start; recognizes and binds to promoters with (subunit)
- RNA poly unwinds part of the double helix to expose unpaired bases on the template strand
169
TSP elongation
- when sigma subunit is released, RNA polymerase loses its enhanced affinity for the promoter and regains its strong generalized affinity for any DNA
- mRNA is extended 5' to 3' and moves antiparallel along the DNA template strand
170
TSP termination
terminator RNA sequences signal the end of transcription
- form hairpin loops
171
hairpin loops
ssRNA folds back on itself bc of comp. base piairng between different regions of the same molecule
- releases both RNA polymerase and RNA chain from DNA
- C and G bond
172
primary transcript
single strand of RNA resulting from transcript
- prokaryotes use primary
- eukaryotes use primary that has underwent RNA processing
173
methylated cap
structure at the 5' end of the euk. mRNA formed by capping enzyme and methyl transferase
- efficient translation of mRNA into protein
174
poly-A-tail
structure at the 3' end of the euk. mRNA consisting of 100-200 A residues
- stabilizes mRNA with ribonuclease and poly-A-polymerase
- efficient translation initation
175
5' and 3' untranslated regions (UTRs)
sequences located just after the methylated cap and just before the poly-A-tail; encoded by exons and doesn't include codons
176
RNA splicing
deletes introns and joins together adjacent exons to form mature mrna in eukaryotes
- splicesome performs RNA splicing and consists of small nuclear ribonucleoproteins (snRNPs)
177
transfer RNA (tRNA)
RNA adapter molecule that places a specific amino acid at the correct position in a growing polypeptide chain at ribosome
*mediates translation of mRNA codons into amino acids
178
anticodon
3 nucleotides in tRNA molecules that recognize codons on mRNA by comp. base pairing and wobble
*** codon and anticodons run antiparallel to one another
179
aminoacyl-tRNA synthetases
enzymes that catalyze the attachment of tRNAs to their corresponding amino acids ---- forming charged tRNAs
*** attach tRNAs to amino acids
180
charged tRNA
tRNA molecule to which the corresponding amino acid has been attached by an amino acyl-tRNA synthetase
- bond between the amino acid and tRNA contains energy that is used to drive peptide bond formation
181
wobble
- allows for one tRNA but more than one codon
- 5' end of anticodon (wobble position) can bind to multiple bases at 3' end of codon
182
peptidyl transferase
the enzymatic activity of the ribosome responsible for forming peptide bonds between successive amino acids
183
aminoacyl (A) site
site on a ribosome to which a charged tRNA first binds
184
peptidyl (P) site
site on a ribosome to which the initiating tRNA first binds and the tRNAs carrying the growing polypeptide are located during elongation
185
exit (E) site
occupied by tRNAs during period just after their disconnection from amino acids by action of peptidyl transferase and before release from ribosomes
186
initiation codon
first codon to be translated (AUG) part of the final protein
187
TLN initiation
1st phase of translation for addition of amino acids during elongation
188
ribosome binding site
region on prokaryotic mRNAs containing initiation codon and SD box
- ribosomes bind with to begin translation
189
Shine-Delgarno box
sequence of 6 nucleotides (5'-AGGAGG-3') in pro.mRNA that is 1 of 2 elements constituting a ribosome binding site
190
initiation factors
proteins that help promote the association of ribosomes, mRNA and initiating tRNA during 1st phase of translation
191
TLN elongation
the ribosome continues to translate each codon in turn. - Each corresponding amino acid is added to the growing chain and linked via a bond called a peptide bond.
192
elongation factors
proteins that aid in elongation of translation
193
polyribosomes
a structure by the simultaneous translation of single mRNA molecule by multiple ribosomes
194
termination
phase of translation that brings polypeptide synthesis to a halt
195
release factors
proteins that recognize stop codons and help end translation
196
polyprotein
polypeptide produced by a translation that can subsequently be cleaved by protease enzymes into 2 or more separate proteins
197
posttranslational modifications
changes that occur to a polypeptide after translation has been completed
198
catabolic pathways
metabolic pathways by which complex molecules are broken down
--- inducible regulation
199
anabolic pathways
metabolic pathways for the synthesis of complex molecules from simplier ones
--- repressible regulation
200
induction
the process by which a signal causes expression of a gene
201
inducer
a small molecule that causes transcription from a gene
--- stimulates the production of protein
202
allolactose
inducer of the genes for lactose utilization
203
repressor
binds to the operon's operator
204
inducer
binds to the repressor and prevents it from binding to the operator when present
205
allosteric proteins
protein that undergoes a reversible change in conformation when bound to another molecule (inducer allolactose)
206
constitutive mutants
strains in which certain gene products are made all the time (irrespective of environmental conditions)
ALL THE TIME
207
operator site
short DNA sequence near a promoter that can be recognized by a repressor protein; binding of repressor to the operator blocks transcription of the gene
208
lacI+ is ______ to LacI-
dominant to lacI- in trans
209
lacIs is _________ to LacI+
dominant to lacI+ in trans
210
RNAP I
transcribe genes that encode major RNA components of ribosomes (rRNAs)
211
RNAP II
transcribes genes that encode proteins
212
RNAP III
transcribes genes that encode tRNAs/other small noncoding RNA molecules
213
enhancer
cis-acting regulatory element that regulates from nearby promoters
--- function by acting as binding sites for TFs and are responsible for spatiotemporal specificity of transcription
214
activator
TF that binds to specific DNA seq. with enhancer elements (CpG islands) and increases the level of transcription of a nearby promoter
215
co-activators
protein that binds to a transcriptional activator and plays a role in increasing transcription levels
216
H. acetyltransferases (HATs)
enzymes that acetylate histone tails lysines resulting in open chromatin
--- favors gene expression by clearing promoters of nucleosomes
217
H. methyltransferase (HMTs)
enzymes that methylate histone tail lysines and arginines and thereby affecting chromatin structure
218
H. deacetylase
enzyme that removes acetyl groups from histone tail lysines
219
H. demethylase
enzymes that removes methyls from histone tail lysines
220
do prokaryotes undergo chromatin remodeling?
NO
lack histones
221
trans vs cis mutations
cis mutations affect the plasmid it is on...not both
- trans elements can work in both plasmids if one is mutated
222
if promoter is mutated...
no other genes will function
223
a super repressor can only repress if
it is bound to operator
224
Oc is ----- to I
epistatic
-- masked the affects of I
225
Can cell grow if lactose is its only carbon source?
no ----- requires beta-galactosidase
