Brainscape's Knowledge GenomeTM

Browse over 1 million classes created by top students, professors, publishers, and experts.


See full index

Genetics and Molecular Biology > Exam 1 > Flashcards

Exam 1 Flashcards

You may prefer our related Brainscape-certified flashcards:
AP® Biology flashcards Biology 101 flashcards
1
Q

What is the dependent variable?

A

What you are measuring/what you care about/the outcome/the effect

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
2
Q

What is the independent variable?

A

What you are manipulating (in hopes of affecting the dependent variable)/ the potential cause

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
3
Q

What is the negative control?

A

The independent variable will not affect the dependent variable, tells us baseline information about the dependent variable

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
4
Q

What is the positive control?

A

The independent variable will affect the dependent variable in a measurable way

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
5
Q

What is the experimental/treatment control?

A

Unknown outcome, what you are testing

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
6
Q

What are standardized variables?

A

Things that are kept the same for treatment and control groups to isolate cause and effect

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
7
Q

What is the central dogma of biology?

A

DNA makes RNA through transcription, RNA makes and amino acid chain through translation, and an amino acid chain makes a protein through folding

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
8
Q

What are proteins?

A

Linear chains of amino acids which fold to make complex shapes capable of doing a specific task in the cell

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
9
Q

What determines the shape and abilities of a protein?

A

The order of specific amino acids in a protein

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
10
Q

Describe the structure of DNA

A

DNA is make of 2 strands of nucleotides, with the nucleotides within a singular strand linked together by covalent bonds, and with the stands being help together by hydrogen bonds between base pairs

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
11
Q

What are the 4 different nucleotides with 4 different nitrogen bases?

A

Thymine, cytosine, adenine, and guanine

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
12
Q

What is a nucleotide composed of?

A

A sugar, a phosphate group, and a nitrogen base

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
13
Q

What differentiates nucleotides?

A

Their nitrogen base

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
14
Q

What nitrogen bases are pyrimidines?

A

Thymine and cytosine

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
15
Q

What nitrogen bases are purines?

A

Adenine and guanine

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
16
Q

What is the difference between pyrimidines and purines?

A

Pyrimidines have one carbon ring and purines have two

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
17
Q

Where on the nucleotide is the phosphate group attached?

A

The 5’ carbon

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
18
Q

Where on the nucleotide is the hydroxyl group attached?

A

The 3’ carbon

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
19
Q

What is a phosphodiester bond?

A

The bond between the 5’ phosphate group and the 3’ hydroxyl group

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
20
Q

How are DNA strands made?

A

By attaching the 5’ phosphate to the 3’ hydroxyl, which creates and strand with a 5’-P end and a 3’-OH end

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
21
Q

What did Edwin Chargaff discover?

A

He discovered that, for any organism’s DNA, the amount of adenine=the amount of thymine and the amount of guanine=the amount of cystosine

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
22
Q

What did Rosalind Franklin contribute to the discovery of the structure of DNA?

A

She took a picture of DNA via x-ray crystallography

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
23
Q

Which bases pair together?

A

Purines pair with pyrimidines (adenine with thymine and guanine with cystosine)

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
24
Q

What are the key features of the DNA double helix?

A
  • Anti parallel strands (one stand goes in the 5’ to 3’ direction and the other goes in the 3’ to 5’ direction)
  • Sugar phosphate “backbones”
  • Bases “glue” stands together with H-bonds
How well did you know this?
1
Not at all
2
3
4
5
Perfectly
25
Q

How many hydrogen bonds does the adenine thymine bond have?

A

2

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
26
Q

How many hydrogen bonds does the guanine cytosine bond have?

A

3

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
27
Q

Which base pairing has a stronger bond?

A

Guanine and cystosine

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
28
Q

What is the common form of a DNA helix? What other forms are there?

A

The common form is B-DNA, but there is also A-DNA and Z-DNA

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
29
Q

Which DNA helices are right handed?

A

A and B

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
30
Q

Which DNA helices are left handed?

A

Z

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
31
Q

What do base pairing angles create?

A

Major and minor groove

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
32
Q

What does underwinding of DNA create?

A

Negative supercoils

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
33
Q

What does over winding of DNA create

A

Positive supercoils

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
34
Q

Which type of supercoil can assist in separating DNA strands?

A

Negative supercoils

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
35
Q

What is a genome?

A

The full hereditary information for an organism (complete set of DNA)

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
36
Q

What is a chromosome?

A

A large, continuous DNA molecule

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
37
Q

What are the 2 classes of cells?

A

Eukaryotic cells and prokaryotic cells

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
38
Q

What are the characteristics of prokaryotic cells?

A
  • Domains: archaea and eubacteria
  • Smaller (1-5 µM) than eukaryotic cells
  • DNA stored in cytoplasm (no nucleus)
  • Only single celled organisms
How well did you know this?
1
Not at all
2
3
4
5
Perfectly
39
Q

What are the characteristics of eukaryotic cells?

A
  • Domain: eukarya
  • DNA stored in nucleus (surrounded by membrane)
  • Organelles (“little organs”) surrounded by membranes with specialized jobs
  • Larger (10-100 µM) thank prokaryotic cells
  • Single and multi-celled organisms
How well did you know this?
1
Not at all
2
3
4
5
Perfectly
40
Q

What are the characteristics of prokaryotic genomes?

A
  • Diverse
  • One or more chromosomes
  • Chromosomes can be linear or circular
  • Can have small, circular plasmids
How well did you know this?
1
Not at all
2
3
4
5
Perfectly
41
Q

What are the characteristics of eukaryotic genomes?

A

Multiple linear chromosomes

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
42
Q

What are eukaryotic chromosomes made out of?

A

Chromatin

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
43
Q

What is a nucleosome?

A

DNA molecules wrapped around histone proteins

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
44
Q

What is the order of packing patterns from DNA to mitotic chromosme?

A

DNA to nucleosome to 30 nm filament to extended form of chromosome to condensed section of chromosome to mitotic chromosome

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
45
Q

What proteins help pack DNA?

A

Cohesion proteins

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
46
Q

What happens when chromosomes are condensed?

A

When DNA is more tightly packed, the genes are less likely to be read to make proteins

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
47
Q

What is euchromatin?

A

Loosely packed DNA actively being read to produce proteins

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
48
Q

What is heterochromatin?

A

Tightly packed DNA not being read

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
49
Q

What loosens DNA packing?

A

Acetylation of histone proteins

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
50
Q

What tightens DNA packing?

A

Methylation of histone proteins

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
51
Q

Describe the structure of RNA compared to DNA

A
  • RNA is single stranded rather than double stranded
  • RNA has uracil instead of thymine
  • RNA has a different sugar than DNA (ribose instead of deoxyribose)
How well did you know this?
1
Not at all
2
3
4
5
Perfectly
52
Q

What can RNA base pair with?

A
  • Nitrogen bases on the same RNA molecule
  • Nitrogen bases on different RNA molecules
  • Nitrogen bases on DNA molecules
How well did you know this?
1
Not at all
2
3
4
5
Perfectly
53
Q

What is the folding of RNA into 3D structures based on?

A

Base pairing

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
54
Q

What is the origin of replication?

A

Specific sites (sequences) where DNA replication starts

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
55
Q

How many origins of replication does E. coli have?

A

1

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
56
Q

How many origins of replication do eukaryotes have?

A

Many (faster for larger genomes)

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
57
Q

What is the replication bubble?

A

Expanded area of replicated DNA

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
58
Q

What is the replication fork?

A

Site of active replication

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
59
Q

How many replication forks are there per replication bubble?

A

2

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
60
Q

What is the function of DNA polymerase?

A

Adding new nucleotide to the 3’ end of a DNA strand

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
61
Q

Where does the energy to add a new nucleotide to a strand of DNA come from?

A

New nucleotides come in as nucleotide triphosphates (like ATP), the loss of two phosphate groups releases energy to power the connection of the nucleotide to the strand

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
62
Q

What is the function of DNA helicase?

A

Unwinds double-stranded DNA, but overwinds the DNA in front of it, which requires topoisomerase to reduce strain

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
63
Q

What is the function of primase?

A

Builds short RNA strands called primers that DNA polymerase can work from to build a DNA strand

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
64
Q

How does primase work?

A
  1. Primase binds to the template strand and synthesizes an RNA primer
  2. When primer is complete, primase is released and DNA polymerase binds and synthesizes new DNA
How well did you know this?
1
Not at all
2
3
4
5
Perfectly
65
Q

In which strand does replication occur continuously?

A

Leading strand

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
66
Q

In which strand does replication occur discontinuously?

A

Lagging strand

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
67
Q

In which strand is DNA synthesized towards the replication fork?

A

Leading strand

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
68
Q

In which strand is DNA synthesized away from the replication fork?

A

Laggin strand

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
69
Q

What are Oakazaki fragments?

A

A series of segments of DNA that are synthesized on the lagging strand

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
70
Q

What happens to the RNA primers on the lagging strand?

A

They are replaced with DNA by DNA polymerase

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
71
Q

What is the function of single stranded binding proteins (SSPBs)

A

They prevent lagging strand from folding on itself and blocking replication

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
72
Q

What are the specific functions of DNA polymerase III (main DNA polymerase)?

A
  • 5’ to 3’ polymerase
  • 3’ to 5’ exonuclease (for proofreading)
How well did you know this?
1
Not at all
2
3
4
5
Perfectly
73
Q

What are the specific functions of DNA polymerase I (specialized DNA polymerase)?

A
  • 5’ to 3’ polymerase
  • 3’ to 5’ exonuclease (for proofreading)
  • 5’ to 3’ exonuclease (for replacing RNA primers)
How well did you know this?
1
Not at all
2
3
4
5
Perfectly
74
Q

What is the function of an exonuclease?

A

Cuts nucleotides off end of nucleic acid strand

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
75
Q

What is the function of DNA ligase?

A

Connects adjacent strands of DNA together to combine Okazaki fragments to form one continuous new strand

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
76
Q

Why does only adding nucleotides to the 3’ end of a strand allow for proofreading and removal of incorrect nucleotides?

A

Adding nucleotides to the 5’ end if one nucleotide is removed by proofreading does not require the triphosphate bond to be cleaved, providing no energy for the bond, while adding nucleotides to the 3’ end if one nucleotide is removed by proofreading requires the triphosphate bond to be cleaved, providing energy for polymerization (bond made)

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
77
Q

What is the end replication problem?

A

Eukaryote’s linear chromosomes can never be fully replicated due to lagging strand dynamics, chromosomes shorten during each replicative cycle

78
Q

What is a telomere?

A

Non-protein coding repetitive sequence found at the ends of chromosomes

79
Q

What is the function of telomeres?

A

They act as a buffer to protect protein coding genes, as they shorten with every replication cycle (part of DNA that shortens instead of protein coding DNA)

80
Q

What is limited by telomeres?

A

Replicative potential of cells (this prevents cancer, but may contribute to aging)

81
Q

What is telomerase?

A

Protein-RNA complex (RNA- directed, DNA synthesis)

82
Q

What is the function of telomerase?

A

It maintains telomere length in gamete producing cells

83
Q

How does telomerase work?

A
  1. Telomerase extends the 3’ end of a DNA strand
  2. The other strand is extended the usual way by primase, DNA polymerase, and ligase
84
Q

What is polymerase chain reaction (PCR)?

A

In vitro method for making copies of DNA sequences

85
Q

What are the uses of PCR?

A

Molecular cloning, diagnostics, forensics, DNA sequencing, gene expression analysis, etc

86
Q

Who invented PCR? What was his goal and solution

A

Kary Mullis
Goal: make more of the DNA he was studying
Solution: use biochemistry of DNA replication, but use heat to break DNA h-bonds and employ short DNA “primers” to define the amplification region

87
Q

What initiates replication in PCR?

A

PCR primers

88
Q

What are PCR primers?

A

Short DNA sequence (oligonucleotides, usually 15-20 nucleotides) produced synthetically and added to PCR reaction

89
Q

What are the components of PCR?

A

Template (source) DNA, oligonucleotide primers, DNA polymerase, DNA nucleotides (dNTPs), buffers/salts

90
Q

What is the process of PCR?

A
  1. Denature (95ºC): split DNA strands (break H-bonds with heat
  2. Anneal/prime (50-60ºC): reduce temp, sequence- specific primers bind (anneal) to target DNA (primers define amplification region (amplicon))
  3. Extend (72ºC): DNA polymerase extends from primer using target as a template
    STEPS ARE REPEATED
91
Q

What organism’s polymerase is used for PCR and why?

A

The DNA polymerase from Thermus aquaticus (Taq), a bacteria found in the hot springs in Yellowstone, is used because its DNA polymerase will not denature during the heating of DNA to separate strands

92
Q

Why does the primer sequence influence annealing temperature?

A

GC base pairs are stronger than AT base pairs, so they can anneal at higher temperatures, also longer sequences can anneal at higher temperatures

93
Q

How is Sanger sequencing different from PCR?

A
  • Only one primer is used
  • No chain reaction
  • Dideoxynucleotides (ddNTPs) are included to prematurely terminate strand synthesis
94
Q

What is the function of dideoxynucleotides (ddNTPs)?

A

They stop strand synthesis

95
Q

What is gel electrophoresis?

A

Uses electricity to separate DNA molcules by size(number of nucleotides)

96
Q

What is the process of Sanger sequencing?

A
  1. PCR with fluorscent, chain-terminating ddNTPs
  2. Size separation by capillary gel electrophoresis
  3. Laser excitation & detection by sequencing machine
97
Q

How many nucleotides can Sanger sequencing sequence?

A

100s-1000s of nucleotides in one read

98
Q

What is a contig?

A

A continuous segment of sequence created through overlapping “reads” (sequences)

99
Q

What is coverage?

A

Number of copies of genome sequenced, more coverage is needed for new genome assembly

100
Q

What do reference genomes allow for?

A

New individual genome sequences with less coverage

101
Q

What is the function of RNA polymerase?

A

Separates the strands of a DNA molecule to build a new RNA molecule 5’ to 3’ that is complementary to one of the DNA strands

102
Q

What do promoter DNA sequences mark?

A

The beginning of genes

103
Q

What is the function of eukaryotic general transcription factors?

A

They bind promoters and recruit RNA polymerase

104
Q

What is TBP?

A

TATA box binding protein

105
Q

What is Rho-indpendent (intrinsic) termination of transcription?

A

Termination cause by hairpin in RNA transcript

106
Q

What is Rho-dependent termination of transcription?

A

Uses Rho translocase to remove RNA polymerase and DNA from the transcript

107
Q

How is RNA modified after transcription?

A

A 5’ methyl-G cap and a 3’ poly-A tail are added

108
Q

What is the purpose of the 5’ methyl-G cap and 3’ poly-A tail?

A

Facilitate export from the nucleus, protect from degradation, facilitate translation (ribosome recruitment)

109
Q

What are exons?

A

Protein coding mRNA

110
Q

What are introns?

A

Non-protein coding mRNA

111
Q

What are removed from mRNA before exit from nucleus?

A

Introns

112
Q

What is RNA splicing?

A

The process of removing introns and connecting exons before the mRNA exits the nucleus

113
Q

What is a spliceosome?

A

Protein-RNA complex that carries out RNA splicing, contains snRNPs

114
Q

What are snRNPs (“snurps”)

A

Small nuclear ribonucleoproteins, contains snRNA (small nuclear RNA) that targets complex based on intron sequences

115
Q

How is mRNA read during translation?

A

5’ to 3’ direction to build new proteins in the N-terminus to C-terminus direction

116
Q

What is a codon?

A

A set of 3 RNA nucelotides

117
Q

What do codons correspond to?

A

One amino acid

118
Q

How is the genetic code redundant?

A

multiple codons per amino acid

119
Q

How is the genetic code unambiguous?

A

only one amino acid per codon

120
Q

What is covalently bonded to tRNA?

A

An amino acid

121
Q

What is an anti codon?

A

Attached to tRNA to base pair with the mRNA codon

122
Q

What is the function of amino-acyl tRNA synthetase?

A

Attaches appropriate amino acid to tRNA

123
Q

What are the components of the ribosome?

A

-rRNA protein complex
-2 subunits come together to initiate translation
-3 tRNA binding sites

124
Q

What is the site of translation?

A

Ribosomes

125
Q

What amino acid do all polypeptides begin with?

A

Methionine (start codon AUG)

126
Q

Describe ribosome recognition and binding of the 5’ end of mRNA in bacteria

A

mRNA ribosome binding site (Shine-Delgarno Sequence) base pairs with rRNA from small subunit, lining up correct AUG start

127
Q

Describe ribosome recognition and binding of the 5’ end of mRNA in eukaryotes

A

-Small ribosomal subunit binds 5’ cap of mRNA
- Kozak sequence helps ribosome find AUG

128
Q

What defined the reading frame of translation?

A

Initiation of translation/position of start codon

129
Q

What are the steps of translation?

A
  1. New tRNA with correct anti codon binds to next mRNA codon in A site
  2. Growing amino acid chain is connected to amino acid from new tRNA
  3. Old tRNA leaves and message slides over to put tRNA holding peptide in P site and to make for for next tRNA in A site
130
Q

What is the function of stop codons?

A

To recruit protein factos that terminate translation

131
Q

What is termination (of translation)?

A

Stop codon recruits release factor (protein, not tRNA), translation complex is disassembled

132
Q

What are polyribosomes (polysomes)?

A

Multiple ribosomes simultaneously translate the same mRNA

133
Q

In what type of cell can transcription and translation occur at the same time and why?

A

Prokaryotic cells because the genes don’t have introns and the cells don’t have a nucleus, so transcription and translation can happen at the same time

134
Q

What do open reading frames (ORFs) contain?

A

A start codon and no premature stop codons

135
Q

What do ORFs help to predict?

A

Gene locations, especially in prokaryotes

136
Q

Why are ORFs less useful for gene predictions in eukaryotic genomes?

A

Removal of introns can remove stops or change reading frame

137
Q

What is a substitution mutation?

A

One nucleotide is replaced by another

138
Q

What is a deletion mutation?

A

One or more nucleotides are removed from the gene

139
Q

What is an insertion mutation?

A

One or more nucleotides are added to a gene

140
Q

Are mutations bad?

A

Sometime, mutations can be good, bad, or neutral

141
Q

What are the types of substitution mutations?

A

Missense, silent, and nonsense

142
Q

What is a missense mutation?

A

Mutation that causes the wrong amino acid

143
Q

What is a example of something caused by a missense mutation?

A

Sickle cell disease

144
Q

What is a silent mutation?

A

Mutation that causes the same amino acid

145
Q

What is a nonsense mutation?

A

Mutation that creates a stop codon

146
Q

What are single nucleotide polymorphisms (SNPs) a result of?

A

Substitutions

147
Q

What is a polymorphism?

A

Variation in DNA sequence

148
Q

What is an SNP

A

Individual nucleotide difference tween different people

149
Q

What types of mutations are frameshift mutations?

A

Deletions and insertions

150
Q

What is a frameshift mutation?

A

Mutations that cause a different set of codons to be read after the mutation (a different reading frame)

151
Q

What types of mutations cause more drastic protein changes?

A

Deletions and insertions

152
Q

What determines cell type and what a cell can do?

A

The active proteins present in a cell

153
Q

What is gene expression?

A

The transcription and translation of a gene to make an active protein

154
Q

Do all cell types have the same DNA?

A

Yes

155
Q

What is the most common way to control a protein’s presence?

A

Regulation of when a gene is transcribed

156
Q

What is constitutive expression?

A

When the gene the is expressed at all times

157
Q

What is an inducible expression?

A

When gene expression is off until actively turned on

158
Q

What is repressible expressions

A

When gene expression is on until actively turned off`

159
Q

How can activator transcription factors increase gene expression?

A

They can bind enhancer DNA, which increases gene expression by bringing general transcription factors

160
Q

What are trans DNA sequences?

A

Anywhere genes for transcription factor proteins
- Activators= increase transcription
- Repressors= decrease transcription

161
Q

What are cis DNA sequences?

A

Near gene binding sites for transcription factors
- Enhancer= attracts activator
- Silencer= attracts repressor

162
Q

What is an operon?

A

Multiple genes with one promoter?

163
Q

Do operons exist in prokaryotes or eukaryotes?

A

Prokaryotes

164
Q

What are the enzymes required to import and break down lactose?

A

β-Galactosidase and galactoside permease

165
Q

When E. coli is growing in a medium with glucose and lactose, what does it eat first?

A

The E. coli eats glucose first, then lactose

166
Q

What must be present for the lac operon to be on?

A

Lactose

167
Q

What must be absent for the lac operon to be on?

A

Glucose

168
Q

What is the positive control of the lac operon?

A

Catabolite activating protein (CAP) transcription factor

169
Q

What is the negative control of the lac operon?

A

Lac repressor transcription factor

170
Q

What happens when there is no lactose present?

A

The repressor, which senses lactose, blocks the promoter when it is binded to the operator of the genes for lactose enzymes, so RNA polymerase cannot attach to the promoter and transcription and gene expression is blocked

171
Q

What happens then lactose is present?

A

The repressor senses the lactose and releases from the operator, which allows RNA polymerase to bind to the promoter and transcription and expression of the genes for the lactose enzymes

172
Q

When is cAMP present?

A

When glucose is low

173
Q

What occurs when cAMP is absent?

A

CAP does not bind to the promoter, so transcription occurs at a low rate

174
Q

What occurs when cAMP is present?

A

CAP binds to the promoter and increases RNA polymerase activity

175
Q

What causes CAP to bind to the promoter?

A

Low or absent glucose, which causes cAMP to be produced, which allows CAP to bind to the promoter and transcription and RNA polymerase activity to occur

176
Q

What does strong expression of the lac operon require?

A

Release of repression and transcriptional activity (high lactose and low glucose)

177
Q

What is the cis regulatory sequence for the lac operon?

A

Binding site for transcription factor

178
Q

What is the rans regulatory sequence for the lac operon?

A

Gene for transcription factor

179
Q

What can be caused by mutations to regulatory DNA sequences?

A

Genetic diseases and cancer by changing the availability of certain proteins in cells

180
Q

What does alternative splicing do?

A

Creates different protein variants in different cells or at different times

181
Q

How does alternative splicing aid in neural connections?

A

Provides a signature for each neuron, allowing neurons to correctly “wire up”

182
Q

What does Dscam regulation?

A

Neuron adhesion

183
Q

How many alternatively spliced forms does Dscam have?

A

19,008

184
Q

What helps to start translation?

A

Eukaryotic initiation factors (eIFs)

185
Q

What happens when eIF2 is phosphorylated?

A

Translation is blocked

186
Q

What happens when eIF2 is not phosphorylated?

A

Translation occurs

187
Q

Why do some viral mRNAs use internal ribosome entry site (IRES)?

A

To circumvent initiation factors

188
Q

What are the untranslated regions?

A

The mRNA before the start codon and after the stop codon?

189
Q

What is the function of untranslated regions?

A

They regulate mRNAs

190
Q

How does RNAi regulate mRNA?

A

Highly specific to one mRNA

191
Q

How does miRNAs regulate mRNA?

A

Regulates multiple mRNAs

192
Q

What is the function of topoisomerase?

A

To reduce strain of overwinding

Genetics and Molecular Biology (2 decks)

Brainscape helps you reach your goals faster, through stronger study habits.
© 2024 Bold Learning Solutions. Terms and Conditions