Brainscape's Knowledge GenomeTM

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


See full index

MCAT Prep > Molecular Bioclass 3 > Flashcards

Molecular Bioclass 3 Flashcards

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

Antiparallel orientation

A

5’ end of one chain is paired with the 3’ end of the other

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

Annealing (hybridization)

A

The bonding of two complimentary strands of DNA into a double-stranded structure

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

Melting (denaturation)

A

The separation of strands

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

Genome

A

The sum total of the organisms genetic information

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

Chromosomes

A

Eukaryotes genomes are composed of several large pieces of linear dis-DNA called chromosomes. Humans have 46. Half from mom and half from dad. 23 pairs

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

DNA gyrase

A

Uses the energy from ATP to twist the gigantic circular molecule. Breaks the dna and twists the two strands around each other making super coils

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

Histones

A

8 of them in a clump. Globular proteins that are wrapped inside dna. Have a lot of amino acids that are positively charged ( lysine and arginine) packs with the negative charged backbone of dna

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

Nucleosomes

A

Composed of dna wrapped around an octane of histones (a group of eight). The octane is composed of two units of each of the histone proteins H2a, H2b, h3 and H4. The string between the beads is a length of double helical DNA called linker DNA and is bound by a single linker histone

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

Chromatin

A

Fully packed DNA. It is composed of closely stacked nucleosomes

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

Stricture of DNA in the Nucleus

A

Deoxyribose, add base, nucleoside ,add 3 phosphates, nucleotide, polymerize with loss of two phosphates, oligonucleotide, continue polymerization, single- stranded polynucleotide, 2 complete chains H-bond in antiparallel orientation
, ds DNA chain, coiling occurs, ds helix, wrap around histones, nucleosomes, complete packing, chromatin

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

Heterochromatin

A

Chromosome portion that is darker. Rich in repeats

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

Euchomatin

A

Lighter regions of the chromosome are less dense. Unwound, active

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

Centromeres

A

Regions of the chromosome were central’s attach during cell division. The fibers attach via kinetochores. Made of heterochromatin and repetitive dna sequences

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

Kinetochores

A

Multiprotein complexes that act as anchor attachment sites for single fibers

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

Telomeres

A

At the end of the chromosome. Repeated 50 to a several hundred times. Usually 6 to 8 base unit pairs long and rich in guanine (G). Made of both single and double stranded DNA

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

Telomeres function

A

To prevent deterioration and also prevent fusion with neighboring chromosomes. No found in prokaryotes. They act as buffers blocking the ends of the chromosomes

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

RNA is different from DNA

A
  1. Single stranded (except in viruses)
  2. Contains uracil instead of thymine
  3. The pentode ring in RNA is ribose rather than 2’ deoxyribose
How well did you know this?
1
Not at all
2
3
4
5
Perfectly
18
Q

RNA less stable

A

RNA is less stable because 2’ hydroxyl can nucleophilically attack the backbone phosphate group of an RNA chain, causing hydrolysis when the remainder of the chain acts as leaving group

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

DNA is more stable

A

DNA does not have a 2’ hydroxyl

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

Heterogeneous nuclear RNA (hnRNA)

A

In eukaryotes the first RNA transcribed from DNA is an immature of precursor for RNA. Processing events are requires (splicing or adding a cap) for hnRNA to become mature mRNA. Only found in eukaryotes

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

Non-coding RNA (ncRNA)

A

Functional RNA not coded into protein. The human genome codes for thousands of rcRNAs, and there are several types. Two major types are tRNA and rRNA

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

Transfer RNA (tRNA)

A

responsible for translating the genetic code. Carries amino acids from the cytoplasm to the ribosome to be added to a growing protein

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

Ribosomal RNA (rRNA)

A

Major component of the ribosome. Humans have 4 different kind. 18S, 5.8S, 28S, and 5S. Almost all of the RNA made in a given cell is rRNA.

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

Function of rRNA

A

Serves as the catalytic function of the ribosome, which is a little odd. In most other cases enzymes are made of polypeptides.

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

Ribozymes

A

Catalytic RNA, or ribonucleic acid enzymes.Since they are capable of performing specific biochemical reactions

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

Small nuclear RNA (snRNA)

A

Molecules (150 nucleotides) associate with proteins to form snRNP (small nuclear ribonucleic particles) complexes in the spliceosome

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

MicroRNA (miRNA) and Small interfering RNA (siRNA)

A

Function in RNA interference (RNAi), a form of post-transcriptional regulation of gene expression. Both can bind specific mRNA molecules to either increase or decrease translation

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

Long ncRNAs

A

Are longer than 200 nucleotides. They help control the basal transcription level in a cell by regulating initiation complex assembly on promoters. They also contribute to many types of post transcriptional regulation, by controlling splicing and translation, and they function in imprinting and X-chromosome inactivation

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

Embryogenesis

A

Cleavage > blastualtion> implantation> neurulation

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

Derivatives of the mesodermal germ layer

A

Skeletal muscles, kidney, and the gentian organs

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

The middle layer of the eyeball wall contains

A

Blood vessles

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

Purines

A

Bases G and A are derived from a precursor called purine
6 carbon ring w/ 5 member ring attached

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

Pyrimidines

A

C, T, and U and pyrimidines
6 carbon ring
Sharp so they CUT

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

Backbone of DNA

A

Made up of sugar connected to phosphate and then another sugar

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

Phosphodiester binds

A

Links nucleotides covalently between 3’ hydroxy group of one deoxyribose and the 5’ phosphate group of the next deoxyribose. Starting at 5’ and going to 3’

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

Oligonucleotide

A

A polymer of several nucleotides linked together is termed an oligonucleotide, and a polymer of many nucleotides is a polynucleotide

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

Watson and crick model

A

Cellular dna is a right-handed double helix held together by hydrogen bonds between bases.

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

DNA H-bonded pair

A

Always a purine plus a pyrmidine

A-T 2 h-bonds and G-C 3 h-bonds

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

Polymerase chain reaction (lab test)

A

Amplify DNA segments from just a little. Done a lot usually with more than one template.
Primers
Template
dNTPs
Taq polymerase
Buffer solution

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

DNA stabilization

A

Phosphodiester bond in backbone
H-bonds between bases
Pi stacking (London dispersion forces)

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

Pi Stacking

A

Special London dispersion force for highly aromatic structures that allows for stacking and increased stabilization

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

Prokaryotes

A

Double stranded dna in a circle in the cytoplasm. They have methylated DNA. Blocks the active site for restriction enzymes. Virus dna is not methylated

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

Methylation

A

Protect prokaryotic dna from cutting enzymes (restriction enzymes)

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

Endonucleases

A

DNA digesting enzymes. Tend to cut palindromic sequence.

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

Palindromic sequence

A

Read 5’ to 3’ on top strand and 5’ to 3’ on the bottom strand. They are usually cleaved

46
Q

How prokaryotes protect their DNA

A

Supercooling - coils the helix further
DNA methylation

47
Q

Eukaryotes liner

A
48
Q

Start Codon

A

AUG - codes for methyanine amino acid

49
Q

Stop Codons

A

UAA- you are annoying
UGA - you go away
UAG- you are gone

No amino acid

50
Q

Number of nucleotides in the genome

A

3 billion

51
Q

Number of genes that can be transcribed

A

35,000 +

52
Q

Intergenic regions

A

Large segments of dna in between genes. Don’t code for anything. They are what make a person unique. Has single nucleotide polymorphisms often mutated

53
Q

Single nucleotide polymorphisms

A

Often mutated from person to person and is what makes us unique

54
Q

Polymerase Errors

A

Point mutations
Small repeats
Insertions/ deletions (small, frame shift)

55
Q

Point mutation (types)

A

Single base pair change that could occur.
Missense
Nonsense
Silent

56
Q

Missense mutation

A

Codon for a becomes a new codon for as. Change the amino acid. Can be simple or dire. Eg no change or sickles cell animea

57
Q

Nonsense mutation

A

Codon for aa becomes STOP codon. Shortened protein. May still be functional

58
Q

silent mutation

A

codon for aa becomes new codon for aa. no effect molecularly but could make less of the protein due to longer time to make the protein and can cause disease .

59
Q

Frameshift mutations

A

Insertions and deletions changes the reading frame . Produces different amino acids. Unless 3 were added or removed

60
Q

Endogenic Damage

A

Reactive oxygen species. Physical damage. Like oxidized dna. Can nitrogenous bases to become cross linked and form covalent bonds with each other . Can break double and single stranded dna (all of these can lead to polymerase errors.)

61
Q

Intrastrand cross linking

A

Covalent bonds between adjacent bases on the same strand of dna. Endogenous damage

62
Q

Interstrand cross linking

A

Covalent bonds between bases on opposite sides of a dna strand. Endogenous damage

63
Q

Exogenous damage

A

Radiation and chemicals. UV radiations
X rays
Chemicals

64
Q

UV radiation

A

Exogenous. Pyrimidine dimmers formed.

65
Q

X rays

A

Double-stranded breaks and translocations. Exogenous

66
Q

Chemicals

A

Can lead to physical damage or to intercalating and thus polymerase errors

67
Q

Transposons

A

Changes dna on a large scale including insertions/ deletions, inversions and duplications.

68
Q

What makes up a transposon.?

A

Transposase - enzyme
Inverted repeats around the enzyme that act as recognition sites

69
Q

Types of transposons 3x

A

IS element- (inverted sequence)

Complex transposons- has the enzyme the inverted repeats and additional genes in between

Composite Transposon- has two tranposons with gene region in between

70
Q

How tranposons contribute to genetic variation

A

Cut and paste from the transposase. Very accurate because the inverted repeat sites are recognition sites. Pastes it in a completely random place.

71
Q

Effect of a single transposon

A

Intergenic region - no effect

Gene for eg. insulin would be no more insulin

72
Q

Reducing the tranposons jumping ability

A

We methylated these regions

73
Q

Bad bases (mismatch, oxidized, cross linked, diners.)

A

Mismatch repair pathway or the nucleotide excursion pathway

74
Q

Mismatch repair pathway

A

During or shortly after replication. Because the parent strand is methylated you could assume the top strand is older and should be restored. You could also search for gaps or Okazaki fragments. Or an incomplete 3’ end.

75
Q

Base/ nucleotide excursion repair

A

Can happen at any time in the cell cycle (ideally before replication). Remove the bad base and replace it with a good base

76
Q

Broken Chromosomes (physical damage or X ray)

A

Homologous directed repair

Non- homologous end joining

77
Q

Homologous directed repair

A

Double stranded dna strand. Relies on the sister chromatid must be present so must happen after dna replication

78
Q

Non-homologous end-joining

A

Can happen at anytime in the cell cycle. Legate
broken ends together. Paste together whatever is left and can result in translocations. Mutagenic because usually lose base

79
Q

DNA Rearrangements (transponsons)

A

Generally don’t lead to repair mechanisms

80
Q

DNA Replication

A

Semiconservative
5’ to 3’
Requires a template
Requires a primer

81
Q

DNA is Semiconservative

A

The two parent strands can be used to create to daughter stands. So preserves one old strand couple with one new strand

82
Q

Enzymes needed for DNA replication

A

Helicase
Topoisomerase
Single stranded binding proteins
Primase
DNA polymerase
Ligase

83
Q

Helicase

A

Unwinds dna by breaking hydrogen bonds

84
Q

Topoisomerase

A

Acts like a scissors that cuts dna backbone, relaxes coils then. Then relighted the backbone back together

85
Q

Primase

A

Synthesizes the primer. Needs to go in the oppositions direction of the parent strand. Can moon walk backwards to add more primers for the rest of the exposed region

86
Q

DNA polymerase

A

Tacks off of the primer and begins to replicate

87
Q

Leading strand versus lagging strand of DNA

A

Leading can task on and replicate. Lagging has to stop and replicate then stop and replicate to form Okazaki fragments

88
Q

Ligase

A

Links Okazaki fragments to help form a single daughter strand

89
Q

Prokaryotes DNA replication (theta replication)

A

5 polymerases
Mains: 3 and 1

90
Q

DNA polymerase 3

A

High processivity (moves fast)
5’ to 3’ and 3’ to 5’ exonuclease activity (can go back to fix errors)
Adds nucleotides at ~400 Bo downstream of ORI
This is the main replicating enzyme
No known function in dna repair

91
Q

DNA polymerase 1

A

Low processivity
5’ to 3’ and 3’ to 5’ exonuclease
Also a 5’ to 3’ to remove primer
Adds nucleotides at RNA primer
DNA excision repair

92
Q

DNA polymerase 2

A

Back up for polymerase 3.
5’ to 3’ polymerase and 3’to 5’ exonuclease
DNA repair

93
Q

DNA polymerase 4 and 5

A

Error prone 5’ to 3’ polymerase activity
DNA repair

94
Q

Replicating End of chromosomes in eukaryotes

A

Lagging strand adds our primers to the 3’ end of the parent strand. Once primers are removed the Ligase can fuse the remaining parts

95
Q

Hayflick Limit

A

Average number a cell divides before it apoptosis

96
Q

Telomere alongation

A

Telomerase Carrie’s it’s own template
It have revers transcriptase activity

97
Q

RNA versus DNA replication

A

Similarities: “start” site, 5’to3’ direction, DNA template

Differences: “STOP” site, no primer, no editing

98
Q

Primary point of translation regulation

A

Transcription is the main point of translation regulation

99
Q

Prokaryotes

A

Transcription and translation happen at the dna time, in the same place.
No mRNA processing

100
Q

Polycistronic

A

Many different proteins from a single mRNA. Prokaryotes

101
Q

Monocistronic

A

“One mRNA, one protein” eukaryotes

102
Q

Eukaryotes RNA polymerase

A

Pol 1 - rRNA
Pol 2 - mRNA
Pol 3 - tRNA

103
Q

tRNA how many are there to code for codons?

A

At least 20 tRNA and at most 61

104
Q

Aminoacyl tRNA synthetase

A

Binds tRNA to the ribosome using 2 ATP

105
Q

Wobble base pairing

A

When there is something GUI at the 5’ end of the anticodon. There’s more flexibility at the 3 point in the codon. Options include (I, G, U)

106
Q

Prokaryotes Ribosome

A

Large subunit 50s
Small subunit 30S
Total = 70S

107
Q

Eukaryotes Ribosome

A

Large subunit 60S
Small subunit 40S
Total = 80S

108
Q

Prokaryotes Shine Dalgarno

A

Checks out the ribosome to make sure everything is running right before translation

109
Q

Eukaryotes KOZAK Sequence

A

Checks out the ribosome to make sure everything is running right before translation

110
Q

Ribosome EPA sites

A

E site - nothing happens
P site- growing protein held here
A site - new amino acid added here

No amino acid for the start codon or the stop codons. Release factor is added at the stop codon, freeing the protein

111
Q

Calculating the number of ATP to make a specific numbered polypeptide.

A

Number of Amino acids * 4= number of ATP
Divide ATP by 30 to get number of glucose in eukaryotes

MCAT Prep (11 decks)

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