Brainscape's Knowledge GenomeTM

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


See full index

Dr. Kolomyjec Genetics > Genetics Test 3 > Flashcards

Genetics Test 3 Flashcards

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

DNA A

A

Unwinding the helix, initiator protein, binds to ORI causing confirmation change, causes helix to destabilize and open up, exposes ssDNA

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

DNA helicase

A

Made of DNA B polypeptides, hexamer of subunits, subsequently recruits holoenzyme to bind replication fork and initiate replication, require energy supplies by hydrolysis of ATP-denatures hydrogen binds and stabilizes double helix

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

Single stranded binding proteins (SSBP)

A

Stabilize the open confirmation of helix, bind specifically to single strands of DNA,

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

DNA gyrase

A

Relieves coiled tension from unwinding of helix (member of the DNA topoisomerases) slide along ahead of helicase to relieve tension

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

Primase: RNA polymerase

A

Synthesizes RNA primer, provides 3’-OH required by DNA polymerase III for elongation, (aka build little short segments of RNA, capable of starting with nothing)

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

DNA polymerase I

A

Removes primer

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

RNA priming

A

Universal phenomena found in everything with DNA

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

Continuous DNA synthesis

A

Leading strand

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

Discontinuous DNA synthesis

A

Lagging strand

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

Okazaki fragments

A

The chunks of DNA that form from the lagging strand

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

DNA ligase

A

Catalyzes formation of phosphodiester bonds and seals nicks and joins Okazaki fragments

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

DNA clamp

A

Prevents core enzyme dissociation from template

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

Proofreading

A

DNA polymerase exonuclease can go back and correct mistakes (3’-5’)

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

Enzymes and proteins that are essential to DNA synthesis

A

DNA polymerase III, SSBPs, DNA gyrase, DNA helicase, RNA primers

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

Shared features of eukaryotic and Bacterial DNA replication

A

Double strand unwound at ORI, replication forks, bidirectional synthesis, requires four triphosphates, primer

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

Why is eukaryotic DNA replication more complicated

A

More DNA, linear chromosomes, DNA complexes with nucleotides

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

Do eukaryotic organisms have one ORI or many?

A

Many, speeds up the process

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

Autonomously replicating sequences (ARSs)

A

120 base pairs of consensus sequence (same sequence in all those places) in yeast

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

Prereplication complex (pre-RC)

A

Assembles at replication ORIs, early GI phase of cell cycle, for controlled timing of DNA replication

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

Does eukaryotic DNA replication have one polymerase or many?

A

Many

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

Polymerase switching

A

Occurs once the primer is in place

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

Telomeres

A

Inert chromosomal ends that protect intact eukaryotic chromosomes from improper fusion or degradation, long stretches of short repeating sequences preserve the integrity/stability of chromosomes

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

Telomerase

A

Eukaryotic enzyme, adds repeats of six nucleotide sequence to 3’ end to fill gaps

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

Ribonucleoprotein

A

RNA serves as template for synthesis of DNA complement (reverse transcriptase)

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
25
Q

Telomerase activity and telomere length linked to….

A

Aging, cancer, other diseases

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

In most eukaryotic somatic cells telomerase is active or not active?

A

Not active

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

What cells maintain telomerase activity - immortalized

A

Stem cells and malignant cells

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

Homologous recombination

A

Genetic exchange at equivalent positions along two chromosomes with substantial sequence homology

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

Genetic recombination involves:

A

Endonuclease nicking, strand displacement and pairing with complement, ligation, branch migration, duplex separation

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

Gene conversion

A

Consequence of homologous recombination, characterized by nonreciprocal genetic exchange between two DNA molecules

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

Bacterial and viral chromosome components

A

Single nucleic acid
Largely devoid of associated proteins
Much smaller than eukaryotic

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

Bacterial chromosomes

A

Circular double stranded DNA compacted into nucleoid

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

Supercoiling

A

Closed circular molecules, more compact and sediment more rapidly

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

Topoisomerase

A

Enzymes that cut one or both DNA strands, wind or unwind helix before resealing ends

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

Polytene chromosomes

A

Represent paired homologs, NOT NORMAL, seen in interphase cells, found in tissues such as salivary, rectal, midgut, fruit flies

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

Polytene chromosomes definition

A

DNA of paired holologs undergoes many rounds of replication without strand separation or cytoplasmic division

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

Puff regions

A

Bulges where DNA has uncoiled that are visible manifestations of high level gene activity (transcription that produces RNA)

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

Lampbrush chromosomes

A

Large with extensive DNA looping, easily isolated from oocytes in diplotene stage or prophase I of meiosis (it’s like a giant puff)

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
39
Q

Chromatin

A

At interphase, eukaryotic chromosomes uncoil and decondense into a form called chromatin which is dispersed throughout the nucleus during interphase

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
40
Q

Histones

A

Positively charged proteins associated with chromosomal DNA in eukaryotes, five main types

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
41
Q

Nucleosome

A

A length of DNA coiled around a core of histones (resembles beads on a string) are condensed several times to form intact chromatids

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

Superhelix

A

The structure the DNA forms when it makes a nucleosome

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

Histone tails

A

Not packed into the folded histone domains, allows for remodeling since we can stick things/remove things from the tails

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

Acetylation

A

Changes the charge if the histone, to make them spread out

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

Methylation

A

Makes the histones stick together

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

Phosphorylation

A

Adds phosphate groups

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

Euchromatin

A

Uncoiled and active, appears unsustained during telophase

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

Heterochromatin

A

Condensed areas are mostly inactive, appears stained during interphase

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

Chromosome banding techniques

A

Differential staining along longitudinal axis of mitotic chromosome (resemble polytene chromosome bands)

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

C-Banding

A

Only centromeres take up stain

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

G-banding

A

Differential staining along length of each chromosome

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
52
Q

Nomenclature for human chromosome banding

A

Based on g banding, nomenclature applied to X chromosome

53
Q

Repetitive DNA sequences

A

Are repeated many times within eukaryotic chromosomes

54
Q

Satellite DNA

A

Highly repetitive and consists of short repeated sequences, found in heterochromatic centromeric regions of chromosomes

55
Q

Moderately repetitive DNA

A

Variable number tandem repeats (VNTRs), minisatelites

56
Q

Variable number tandem repeats (VNTRs)

A

Repeating DNA sequences 15-100 bp long, found within and between genes

57
Q

Micro satellites or STRs (short tandem repeats)

A

Tandemly repeated sequence, dispersed throughout genome

58
Q

Short interspersed elements (SINES) and long interspersed elements (LINES)

A

Transposable sequences that are mobile and can relocate within genome, dispersed not tandemly repeated

59
Q

Retrotransposons

A

Transposable elements generated via RNA intermediate (LINES)

60
Q

Pseudogenes

A

Large number of single-copy noncoding regions

61
Q

Unambiguous

A

Each triplet specifies only one amino acid

62
Q

Degenerate

A

A given amino acid can be specifies by more than one triplet code

63
Q

Start and stop signals

A

Triplets that initiate and terminate translation

64
Q

Commaless

A

Once translation begins the codons move in sets of three, no commas

65
Q

Nonoverlapping

A

Any single ribonucleotide within mRNA is part of one triplet

66
Q

Colinear

A

Sequence of codons in a GENE is colinear (genes sequence in DNA matches RNA matches the rest of the strands)

67
Q

Nearly universal

A

A single coding dictionary is used by viruses, prokaryotes, archaea, and eukaryotes

68
Q

mRNA (messenger)

A

Serves as intermediate in transferring genetic information from DNA to proteins (carries from DNA to ribosome)

69
Q

Triplet code

A

Provides 64 codons to specify 20 amino acids

70
Q

Reading frame

A

Contiguous sequence of nucleotides

71
Q

Frameshift mutation

A

Insertions or deletions shift reading frame and change codons downstream

72
Q

Nonoverlapping

A

Genetic code reads three nucleotides at a time in continuous linear manner (during translation genetic code is nonoverlapping)

73
Q

What is meant when it is said that the genetic code is degenerate?

A

Many amino acids specified by more than one codon (only tryptophan and methionine are encoded by a single codon)

74
Q

The wobble hypothesis

A

The initial two ribonucleotides of triplet codes are often more critical than the third

75
Q

Methionine (AUG) - initiator codon

A

Initial amine acid incorporated into all proteins

76
Q

Termination codons

A

UAG, UAA, UGA, do not code for any amino acid, translation terminates when these codons are encountered

77
Q

Nonsense mutations

A

Mutations that produce a stop codon internally in gene, translation is terminated and a partial polypeptide is produced

78
Q

Phage MS2

A

Bacteriophage that infects E. coli

79
Q

Mitochondrial DNA exemptions to universal genetic code:

A

Codon UGA encodes tryptophan in yeast and humans instead of termination, AUA encodes internal insertion of methionine instead of isoleucine

80
Q

Overlapping genes

A

Single mRNA has multiple initiation points and creates different reading frames

81
Q

ORF open reading frame (overlapping genes)

A

DNA sequence produces RNA with start and stop, series of triplet codons specify amino acids to make polypeptide

82
Q

Transcription

A

RNA synthesized on DNA template

83
Q

Promoters

A

Specific DNA sequences in 5’ region upstream of initial transcription point

84
Q

Consensus sequences

A

DNA sequences homologous in different genes of same organism

85
Q

Chain elongation

A

Ribosomes are added to RNA chain, elongation proceeds under direction of core enzyme

86
Q

Termination

A

Enzyme transverse entire gene until a termination nucleotide sequence is encountered

87
Q

Transcription in eukaryotes

A

Occurs within nucleus, mRNA must leave nucleus for translation

88
Q

Transcription factors

A

Scan/bind DNA, enhancers and silencers

89
Q

RNA polymerase 1 makes…

A

rRNA in the nucleolus

90
Q

RNA polymerase II makes

A

mRNA and snRNA in the nucleoplasm

91
Q

TATA box

A

Core promoter element, determines transcription start site

92
Q

Posttranscriptional modifications

A

Addition of 5’ cap, addition of 3’ tail, excision of introns

93
Q

Introns

A

Regions of initial RNA transcript not expresses in amino acid sequence of protein

94
Q

Exons

A

Sequence retained and expressed

95
Q

Splicing

A

Introns are removed, exons are joined together in mature mRNA, mature mRNA is smaller than initial RNA

96
Q

Self splicing RNAs

A

Self excision group I introns occurs in bacteria, lower eukaryotes, and higher in plants

97
Q

Spliceosome

A

Pre-mRNA introns spliced out by spliceosome, reaction involves formation of lariat structure

98
Q

Substitution editing

A

Identities of individual nucleotide bases are altered; prevalent in mitochondria and chloroplasts RNA derived in plants

99
Q

Insertion/deletion editing

A

Nucleotides are added/deleted from total number of bases, prevalent in mitochondrial and chloroplasts RNAs

100
Q

tRNAs transfer RNA

A

Adapt genetic information present as specific triplet codons in mRNA to corresponding amino acid

101
Q

Ribosomes

A

Have an essential role in expression of genetic information

102
Q

rDNA

A

rRNA genes, moderately repetitive DNA fraction present in clusters at various chromosomal sites

103
Q

Structure of tRNA

A

Cloverleaf

104
Q

Anticodon

A

tRNA has anticodon that complementarily base pairs with codon in mRNA

105
Q

Aminoacylation: tRNA charging

A

Before translation can proceed, tRNA molecules must be chemically linked to respective amino acids

106
Q

Three steps of translation of mRNA

A

Initiation, elongation, termination

107
Q

Initiation

A

Initiation complex = small robosomal subunit + initiation factors + mRNA at codon AUG

108
Q

Initiation factors

A

Small and large ribosomal subunits, mRNA molecule, GTP, charged initiator tRNA, Mg2+, imitation factors

109
Q

Elongation

A

Both ribosomal subunits assembled with mRNA, forms P and A site

110
Q

Termination

A

Signaled by stop codons in A site

111
Q

GTP dependent release factors

A

Stimulates hydrolysis of polypeptide from peptidyl tRNA - released from translation complex

112
Q

Polysomes or polyribosomes

A

mRNAs with several ribosomes translating at once, as mRNA passes through ribosome, it’s free to associate with another small subunit

113
Q

Where does transcription occur in eukaryotes?

A

Nucleus

114
Q

Where does translation occur in eukaryotes?

A

Cytoplasm

115
Q

Kozak sequence

A

Eukaryotic mRNAs contain luring (A or G) three bases upstream from AUG initiator codon, followed by a G
(A/NNAUGG

116
Q

Translation in eukaryotes requires…

A

More factors of initiation, elongation, and termination

117
Q

Are ribosomes in eukaryotes free floating?

A

Not all of them, usually associated with endoplasmic reticulum

118
Q

Alkaptonuria and phenylketonuria

A

Result from mutations that lead to metabolic blocks

119
Q

Phenylketonuria (PKU)

A

Phenylalanine hydroxylase is inactive in affected individuals, phenylalanine is not converted into tyrosine and enters cerebrospinal fluid, causing mental retardation

120
Q

One gene:one enzyme hypothesis

A

George Beadle showed genes are directly responsible for synthesis of enzymes (purposely exposed neurospora to bad things trying to force mutations, partner was Tatum)

121
Q

One gene: one polypeptide chain hypothesis

A

Nearly all enzymes are proteins - not all proteins are enzymes, proteins have subunit structure with two or more polypeptide chains

122
Q

Sickle cell anemia

A

Recessive genetic disease, affected individuals are homozygous for the gene, makes the blood cells pointy and easier to clog passages, heterozygotes are carried but largely unaffected

123
Q

Chemical differences between normal and sickle cell hemoglobin

A

HbS and HbA hemoglobin differ by single peptide fragment

124
Q

Colinearity

A

Order of nucleotides in gene correlates directly with order of amino acids in corresponding polypeptide

125
Q

Polypeptides

A

Precursors to proteins, amino acids assembled on and released from ribosomes as polypeptides

126
Q

Proteins

A

Polypeptides folded up into a functional three dimensional conformation

127
Q

Amino acids

A

Add to the diversity of proteins, carboxyl group on one side and amino acid on the other making it positive and negatively charged, and a r group which determines the overall reactivity of the amino acid and type of amino acid

128
Q

Peptide bond

A

Dehydration reaction facilitates bond between carboxyl group of one amino acid and amino acid group of another

Dr. Kolomyjec Genetics (7 decks)

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