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MCAT > 1B: Transmission of genetic information from the gene to the protein > Flashcards

1B: Transmission of genetic information from the gene to the protein Flashcards

1
Q

Nucleotides

A

Monomers of nucleic acids, consists of sugar, nitrogenous base and phosphate group

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2
Q

Types of Nucleotides

A

Thymine, Adenine, Guanine, Uracil

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3
Q

Structure of Nucleotides

A

Phosphorus is linked at the 5 carbon of the sugar; Nitrogenous Base is linked to the 1 carbon of the sugar

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4
Q

Pyrimidines

A

Single ring; Cytosine, Uracil, Thymine

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5
Q

Purines

A

Two rings; Adenine, Guanine

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6
Q

Nucleoside

A

Sugar + Nitrogenous Base

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7
Q

Types of Nucleosides

A

Cytidine, Uridine, Adenosine

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8
Q

DNA

A

Deoxyribonucleic Acid

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9
Q

Double Helix

A

2 single strands of DNA wound around each other held together by hydrogen bonds

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10
Q

Watson-Crick Model

A

Two linear strands running antiparallel and twisted in a right-handed spiral; bases are located inside of the helix

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11
Q

Base Pairing Specificity

A

Nucleobases are connected via hydrogen bonds:
A2T
C3G
DNA with more G-C are more stable

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12
Q

Function of DNA in transmission of Genetic Information

A

Complementary base pairing property allows for DNA replication and transmission of genetic information

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13
Q

Central Dogma

A

DNA -> RNA -> Protein

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14
Q

Denaturation of DNA

A

dsDNA comes apart due to heating or a change in pH

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15
Q

Annealing of DNA

A

ssDNA joins again due to complementary nucleotide sequences and random molecular motion

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16
Q

Hybridization of DNA

A

Denatures two different DNA sequences then uses ssDNA from each to anneal to dsdna

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17
Q

Process of PCR

A

Denature -> Anneal -> Extend

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18
Q

Mechanism of Replication

A
  1. Separation of Strands

2. Coupling of Free Nucleic Acids

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19
Q

Enzymes of Replication

A
  1. DNA Gyrase
  2. Helicase
    - SSB
  3. Primase
  4. DNA Pol III
  5. DNA Pol I
  6. DNA Ligase
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20
Q

Helicase

A

Unwinds double helix of DNA

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21
Q

DNA Pol III

A

Binds one strand of DNA from an RNA primer, moves 3’ to 5’ producing a leading strand

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22
Q

Primase

A

Produces RNA primers at the 5’ end, allowing for the synthesis of Okazaki fragments

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23
Q

Okazaki Fragments

A

Short discontinued fragments of replication products on the lagging strand

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24
Q

DNA Pol I

A

Removes RNA primers by the 5’ end to 3’ end

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25
Q

DNA Ligase

A

Seals the spaces in the strand between the Okazaki Fragments

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26
Q

Single-Strand Binding Protein

A

Responsible for keeping the DNA unwound after helicase unwinds the helix

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27
Q

DNA Gyrase

A

Uncoils DNA ahead of the replication fork

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28
Q

Semi-conservative nature of replication

A

Each DNA helix contains one parent strand and one new strand; older DNA has more methyl groups added so its always possible to determine which strand is older

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29
Q

Origin of Replication

A

Point at which replication begins; multiple points in eukaryotes and singular in prokaryotes

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30
Q

Telomerase

A

Replicates the end of DNA molecules which consist of telomeres that help keep genetic information and prevent it from being lost during replication

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31
Q

Repair during Replication

A

DNA Pol has proofreading activity (3’->5’ exonuclease) which replaces incorrect nucleotides

DNA Pol I has 5’->3’ exonuclease activity which allows for removal of incorrect nucleotides

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32
Q

Repair of Mutation

A 
Mismatch
Base-Excision
Nucleotide-Excision
Nick Translation
SOS Response
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33
Q

Mismatch Repair

A

Enzymes recognize incorrectly paired bases and cuts out the stretch of DNA containing the mismatch; utilizes methylations to determine old from new strand

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34
Q

Base-Excision Repair

A

A single base is removed and replaced using DNA Pol and Ligase

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35
Q

Nucleotide-Excision Repair

A

Damaged nucleotide gets cut out and replaced (due to thymine dimers)

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36
Q

Nick Translation

A

RNA primers are replaced with DNA through 5’ to 3’ activity

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37
Q

SOS Response

A

When there is too much DNA for normal repair; the DNA Pol replicates over the damaged area as if it were normal

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38
Q

Triplet Code (Codon)

A

Sequence of nucleotides of mRNA that codes for amino acids; 3 nucleotides = single amino acid

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39
Q

Anticodon

A

3 bases at the end of tRNA (transfer anticodon) that correspond to the nucleotide triplet in mrNA during translation

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40
Q

Degenerate Code

A

Multiple 3 codon combinations code for the same amino acid (20 total); more than one codon codes for a given amino acid

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41
Q

Wobble Pairing

A

When two nucleotides in RNA molecules do not follow Watson-Crick base pairing rules

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42
Q

Types of Wobble Base Pairs

A 
G-U
I-U
I-A
I-C
I=hypoxanthine
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43
Q

Missense Mutations

A

A new nucleotide changes the codon to produce a changed amino acid in protein

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44
Q

Nonsense Mutations

A

A new nucleotide changes the codon to a stop codon that prematurely truncates a protein

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45
Q

Initiation Codon

A

AUG (methionine); starts the translation process
Prokaryotes = Shine-Delgarno Sequence
Eukaryotes = Kozak Sequence

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46
Q

Termination Codon

A

End translation of the mRNA strand
UAA
UAG
UGA

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47
Q

mRNA

A

Carries genetic information (in the form of codons) that corresponds to amino acids for protein synthesis
5’ terminal is capped by a 7-methyl guanosine triphosphate cap; 3’ end is added poly-A tail

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48
Q

tRNA

A

In the cytoplasm, directs translation of mRNA into proteins; contain anticodon

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49
Q

rRNA

A

Necessary for ribosome assembly, plays a role in mRNA binding to ribosomes and in translation, contains active site for catalysis (peptide bond formation)

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50
Q

Mechanism of Transcription
[Eukaryotes = Nucleus]
[Prokaryotes = Cytoplasm]

A

Initiation -> Elongation -> Termination

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51
Q

Initiation

A

RNA Pol binds to the promoter region of DNA

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52
Q

Elongation

A

Transcription factors unwind the DNA strand and allow RNA Pol to transcribe a strand of DNA into a strand of mRNA; C3G, A2U

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53
Q

Termination

A

RNA Pol reaches a terminator sequence and then releases the mRNA polymer and detaches from the DNA

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54
Q

Eukaryotic Structure

A

5’ UTR
Coding Sequence
3’ UTR

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55
Q

Coding Sequence

A

Where translation begins and ends; contains amino acid sequences for protein synthesis during translation

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56
Q

3’ UTR

A

Contains crucial information for mRNA stability

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57
Q

Processing in Eukaryotes

A
  1. Cap Addition
  2. Polyadenylation
  3. Splicing
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58
Q

Cap Addition

A

Addition of a 5’ methyl guanosine cap that occurs during transcription; prevent chain degradation

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59
Q

Polyadenylation

A

A poly-A tail is added to the 3’ end; enhances the stability of mRNA and regulates transport to cytoplasmic compartment

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60
Q

Splicing

A

Removes introns

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61
Q

Introns

A

Not expressed in proteins

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62
Q

Exons

A

Encoding sequences and they are reserved

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63
Q

Ribozymes

A

Ribonucleic Acid Enzymes; catalyzes biochemical reactions, join amino acids together and form protein chains; play a role in RNA splicing, viral replication and RNA biosynthesis

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64
Q

Spliceosomes

A

Splicing machines that remove and cut introns from pre-mRNA

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65
Q

snRNA

A

Small nuclear RNA, couples with snRNPs that 5’ and 3’ splice sites of introns

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66
Q

snRNPs

A

Combine of snRNA and protein factors that are essential in intron removal

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67
Q

Eukaryotic Ribosome

A

40S + 60S; 80S

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68
Q

Prokaryotic Ribosome

A

30S + 40S; 70S

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69
Q

General Ribosome Structure

A

mRNA binding site (small subunit); E site, P site and A site (large subunit)

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70
Q

P site

A

Binds to tRNA and extends amino acid chain

71
Q

A site

A

Binds to tRNA holding new amino acid

72
Q

E site

A

When a stop codon is encountered, release factors are bound and the chain falls off

73
Q

Post-Translational Modification

A 
Glycosylation
Acetylation
Methylation
Sulfation
Phosphorylation
74
Q

Post-Translational Modification

A 
Glycosylation
Acetylation
Methylation
Sulfation
Phosphorylation
75
Q

Chromosomal Proteins

A

Histones & Non-Histone

76
Q

Histones

A

Order & Package DNA into Nucleosomes; aids with gene regulation; allows DNA to fit inside the nucleus

77
Q

Non-Histones

A

Regulatory and Enzymatic Function

78
Q

Single copy DNA

A

Holds most of the organisms genetic information; protein synthesis & gene expression; holds most of the protein-coding genes; low rates of mutation

79
Q

Repetitive DNA

A

Concentrated at centromeres, not translated, high rates of mutation

80
Q

Moderate Repetitive DNA

A

Transcribed by RNA Pol I or III; contains protein-coding genes

81
Q

Highly Repetitive DNA

A

Not transcribed; contains no genes

82
Q

Highly Repetitive DNA

A

Not transcribed; contains no genes

83
Q

Supercoiling

A

Compacts DNA so it doesn’t get tangled onto itself

84
Q

Positive Supercoil

A

Left Handed; difficult to unwind

85
Q

Negative Supercoil

A

Right Handed; easier to unwind

86
Q

Topoisomerases

A

Alter DNA topology to carry proper functions

87
Q

Topoisomerase I

A

Remove DNA supercoils; break strands during recombination; condense chromosomes

88
Q

Topoisomerase II

A

Cuts strands to manage DNA tangles and supercoils

89
Q

Chromatin

A

Makes up the nucleus and function in gene expression and repression

90
Q

Heterochromatin

A

Tightly packed; contains more DNA; late replication

91
Q

Heterochromatin

A

Dense; Few or No Genes; Replicates Late; Not Transcribed

Increased Acetylation & Decreased Methylation

92
Q

Euchromatine

A

Loose; Lots of Genes; Replicates Early; Can be transcribed

Increased Methylation & Decreased Acetylation

93
Q

Euchromatin

A

Loose; Lots of Genes; Replicates Early; Can be transcribed

Increased Methylation & Decreased Acetylation

94
Q

Telomere

A

Highly conserved DNA sequence located at the end of linear eukaryotic chromosomes; TTAGGG repeated sequence

95
Q

Centromere

A

DNA sequence

96
Q

Centromere

A

Made of heterochromatic DNA; center of chromosomes; microtubule spindle fibers attached

97
Q

Centromere

A

Made of heterochromatic DNA; center of chromosomes; microtubule spindle fibers attached

98
Q

Operon

A

Determines whether a gene is on or off through use of a repressor, inducer etc; the genes down the operon are either expressed together or not at all

99
Q

Repressor

A

Reduces transcription

100
Q

Inducer

A

Increases transcription

101
Q

Inducer

A

Increases transcription

102
Q

Jacob-Monod Model

A

Binding site for the lac repressor is near the transcription start site; operator prevents the repressor from binding

103
Q

Jacob-Monod Model

A

Binding site for the lac repressor is near the transcription start site; operator prevents the repressor from binding; when lactose binds to repressor; genes for galactosidase are transcribed

[R]==========[o][s]============
R= Regulatory Gene
O= Operator
S= Structural Gene

104
Q

Jacob-Monod Model

A

Binding site for the lac repressor is near the transcription start site; operator prevents the repressor from binding; when lactose binds to repressor; genes for galactosidase are transcribed

[R]==========[O][S]============
R= Regulatory Gene
O= Operator
S= Structural Gene

105
Q

Repressor

A

Reduces transcription by binding to the operator blocking RNA Pol binding to the promtor

106
Q

Jacob-Monod Model [Prokaryotes]

A

Binding site for the lac repressor is near the transcription start site; operator prevents the repressor from binding; when lactose binds to repressor; genes for galactosidase are transcribed

[R]==========[O][S]============
R= Regulatory Gene
O= Operator
S= Structural Gene

107
Q

Gene Repression [Bacteria]

A

Inhibition of gene expression by changing regulatory protein activity

108
Q

Repressor

A

Reduces transcription by binding to the operator and block the activity of RNA Pol

109
Q

Inducer

A

Increases transcription

110
Q

Jacob-Monod Model

A

Binding site for the lac repressor is near the transcription start site; operator prevents the repressor from binding

111
Q

Jacob-Monod Model

A

Binding site for the lac repressor is near the transcription start site; operator prevents the repressor from binding; when lactose binds to repressor; genes for galactosidase are transcribed

[R]==========[o][s]============
R= Regulatory Gene
O= Operator
S= Structural Gene

112
Q

Jacob-Monod Model

A

Binding site for the lac repressor is near the transcription start site; operator prevents the repressor from binding; when lactose binds to repressor; genes for galactosidase are transcribed

[R]==========[O][S]============
R= Regulatory Gene
O= Operator
S= Structural Gene

113
Q

Repressor

A

Reduces transcription by binding to the operator blocking RNA Pol binding to the promtor

114
Q

Gene Repression [Bacteria]

A

Inhibition of gene expression by changing regulatory protein activity; through the use of a repressor

115
Q

Gene Repression [Bacteria]

A

Inhibition of gene expression by changing regulatory protein activity; through the use of a repressor

116
Q

Transcriptional Regulation

A

Involves transcription factors through use of enhancers and silencers

117
Q

Enhancers

A

Increases transcription upon binding

118
Q

Silencers

A

Decreases transcription upon binding

119
Q

DNA Binding Proteins

A

Polymerases, Nucleases, Histones; SSBP

120
Q

DNA Binding Proteins

A

Polymerases, Nucleases, Histones; SSBP

121
Q

Post-Transcriptional Control

A

Modification of normal nucleotides occurs to control the structure of tRNAs and rRNAs:
Splicing, Cap & Tail, Methylation

122
Q

Splicing

A

Introns are removed and exons remain

123
Q

5’ Cap & 3’ Poly-A Tail

A

Protects RNA from degradation

124
Q

Cancer

A

A result of failure of normal cellular controls; divides without regulation; stimulates angiogenesis; they avoid apoptosis

125
Q

Oncogenes

A

Genes that have the potential to cause cancer; speeds up cell division

126
Q

Proto-oncogenes

A

A normal gene that can become an oncogene due to mutations or increased expression

127
Q

Antioncogene (Tumor Suppressor Genes)

A

Protects cells from cancer; they dampen or repress the regulation of the cell cycle or promote apoptosis

128
Q

Antioncogene (Tumor Suppressor Genes)

A

Protects cells from cancer; they dampen or repress the regulation of the cell cycle or promote apoptosis

129
Q

Regulation of Chromatin Structure

A

Modified via methylation, acetylation, phosphorylation

130
Q

Regulation of Chromatin Structure

A

Modified via methylation, acetylation, phosphorylation

131
Q

Nucleosome

A

Repeating subunit that is made of histones

132
Q

Histones

A

H1, H2A-H2B [tetramer], H3 -H4 [tetramer]

133
Q

DNA Methylation

A

Blocks promoter so that no transcription factors can bind for gene expression to occur (works as a repressor); plays a role in cell differentiation and embryonic development

134
Q

Non-Coding RNAs

A

Not translated into a protein; regulate RNA Splicing, DNA replication and Gene regulation

135
Q

Non-Coding RNAs

A

Not translated into a protein; regulate RNA Splicing, DNA replication and Gene regulation

136
Q

Recombinant DNA

A

DNA composed of nucleotides from two different sources

137
Q

DNA Cloning

A

Introduces a fragment of DNA into a vector plasmid

138
Q

Restriction Enzyme (Endonuclease)

A

Cuts a plasmid and DNA fragment to leave them with sticky ends; joining fragment to plasmid it can be introduced into a bacterial cell and permitted to replicate

139
Q

Vector Components

A

OoR, Fragment of Interest, One Gene for Ab Resistance so that the colony could be selected after replication

140
Q

DNA Libraries

A

Large collections of known DNA sequences

141
Q

Genomic Libraries

A

Large fragments of DNA (coding and noncoding regions of the genome)

142
Q

Generation of cDNA

A

mRNA is purified and converted back to DNA by reverse transcriptase

143
Q

cDNA Library

A

Consists of cloned cDNA inserted into particular host cells

144
Q

DNA Hybridization

A

Joining of complementary base pair sequences from two different strands of DNA

145
Q

Polymerase Chain Reaction (PCR)

A

Amplifies the size of DNA from a small piece of DNA; 3 steps: Denature, Anneal, Elongate

146
Q

Polymerase Chain Reaction (PCR)

A

Amplifies the size of DNA from a small piece of DNA; 3 steps: Denature, Anneal, Elongate

147
Q

Agarose Gel Electrophoresis

A

Separates DNA molecules by size

148
Q

Southern Blotting

A

Detects presence and quantity of various DNA strands in a sample

149
Q

Southern Blotting

A

Detects presence and quantity of various DNA strands in a sample

150
Q

DNA Sequencing

A

Using ddNTPs (dideoxyribonucleotides) which terminate the DNA chain because they lack a 3’ Hydroxyl Group

151
Q

DNA Sequencing

A

Using ddNTPs (dideoxyribonucleotides) which terminate the DNA chain because they lack a 3’ Hydroxyl Group; sequence read directly from gel

152
Q

Gene Therapy

A

A method of curing genetic deficiencies by introducing a functional gene with a viral vector

153
Q

Transgenic Mice

A

Mice integrated with a gene of interest into the germ line or embryonic stem cells of a developing mouse; can be mated to select for transgene

154
Q

Knockout Mice

A

Created by deleting a gene of interest

155
Q

Knockout Mice

A

Created by deleting a gene of interest

156
Q

Northern Blotting

A

Determines size and sequence information of mRNA; utilizes radiolabeled RNA

157
Q

RT-qPCR

A

mRNA is reverse transcribed followed by quantitative PCR

158
Q

Western Blotting

A

Quantifies the type and size of a protein

159
Q

Location of the expression

A

Uses fluorescent protein marker

160
Q

Location of the expression

A

Uses fluorescent protein marker

161
Q

Stem Cells

A

Cells that have the ability to differentiate into other specialized cells; divides to produce more stem cells

162
Q

Stem Cells in Humans

A

Found in Bone Marrow, Adipose Tissue and Blood

163
Q

Function of Stem Cells

A

Self-renewal, differentiation into specialized cells

164
Q

Hierarchy of Stem Cells

A

Totipotent -> Pluripotent -> Multipotent -> Oligopotent -> Unipotent

165
Q

Hierarchy of Stem Cells

A

Totipotent -> Pluripotent -> Multipotent -> Oligopotent -> Unipotent

166
Q

Totipotency

A

Ability to divide and produce all of the differentiated cells in an organism
e.g. Zygotes & Spores

167
Q

Pluripotency

A

Ability to differentiate into any of the three germ layers (endoderm, mesoderm, ectoderm)
e.g. Blastocyst

168
Q

Multipotency

A

Describes progenitor cells which have the gene activation potential to differentiate into multiple but limited cell types
e.g. Hematopoietic Stem Cells

169
Q

Oligopotency

A

Describes progenitor cells to differentiate into a few cell types
e.g. Lymphoid/Myeloid Stem Cells

170
Q

Unipotency

A

One stem cell that differentiates into only one cell type

171
Q

Unipotency

A

One stem cell that differentiates into only one cell type

e.g Hepatoblast (become hepatocytes)

172
Q

Unipotency

A

One stem cell that differentiates into only one cell type

e.g Hepatoblast (become hepatocytes)

173
Q

Medical Applications of DNA Technology

A

Diagnose Genetics & Infectious Diseases
Development of Vaccines
Therapeutic Hormones
Human Gene Therapy

MCAT (31 decks)

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