Brainscape's Knowledge GenomeTM

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


See full index

IMS > Nucleic Acids and DNA Replication > Flashcards

Nucleic Acids and DNA Replication Flashcards

1
Q

What are the 3 Components of DNA & RNA?

A

Nitrogenous Base
Pentose Sugar
Phosphate group

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

What are the Nitrogenous bases in DNA/RNA?

A

Pyrimidine - CTU

Purine - GA

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

What does the Phosphate group do?

A

Act as a bridge between adjacent ribose/deoxyribose groups

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

What does ATP consist of?

A

3 phosphate groups, ribose and adenine

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

How is a DNA helix held together by?

A

Base Pairing
C with G
T with A

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

When does A-U bonding (RNA) occur?

A

Transcription

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

What is the Structural feature of a DNA double helix?

A

Hydrophobic in centre away from water and Hydrophilic on the outer

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

How are Hydrophobic bases in DNA stabilised?

A

H-bonding between bases on complimentary strands

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

How are Hydrophilic bases in DNA stabilised?

A

Sugar-phosphate backbone stabilised by electrostatic and H-bonding with water

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

What kind of Interactions to stacked bases have?

A

Weak transient electrostatic interactions (van der waals)

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

What are RNA structural features?

A

Single-stranded RNA adopt secondary structures through base pairing

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

What is the difference between nucleotides in DNA/RNA polymers?

A

Base on individual units

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

What is the Polymer described by?

A

Sequence and number of bases

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

What are nucleic acids defined by?

A

Size and direction

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

Where are Nucleotides always added in a polynucleotide chain?

A

3’- end

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

How is a 3’-5’ phosphodiester bond formed?

A

a-phosphate of new nucleotide reacts with 3’-OH group of polymer

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

What direction does the chain grow?

A

5’-3’ direction. always

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

What is always at the start of a Nucleic acid chain?

A

5’ Phosphate at the start and terminates with a 3’ OH

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

Where is DNA in a Eukaryotic cell?

A

Nucleus and helps to compact

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

What is Chromatin?

A

Histone-bound DNA

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

What is a Nucleosome?

A

Basic unit of compacted DNA

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

What is the Core particle of a Nucleosome consist of?

A

Octamer with 2 copies of 4 Histone proteins (H2A,H2B,H3,H4)

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

What does core DNA consist of?

A

146 BP which wraps around histone core

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

What does a Chromosome contain during replication?

A

2 chromatids linked by a centromere

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

What does each Chromatid contain?

A

1 single DNA molecule compacted as chromatosomes

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

At what phase during Cell cycle does DNA replication take place?

A

S phase of Interphase

27
Q

What is DNA replication vital for?

A

Cell growth, Repair, Reproduction

28
Q

What is the model used for DNA replication

A

Semiconservative model - parent strand seperated creating 2 single strands, each strands used as template for complimentary strand

29
Q

When given a DNA sequence, how would you work out the complimentary strand?

A

Work out the opposite pairs and then write it backwards for e.g
5’-AGTCT-3’
compliment is 3’-TCAGA-5’
Written as 5’-AGACT-3’

30
Q

What is the 1st step to DNA replication?

A

Replication Fork Formation

31
Q

How is the replication fork formed?

A

Double strand DNA unzip into 2 single strands, the strands form a Y shaped replication fork used as a template

32
Q

How are DNA double strands split into 2 single strands?

A

Base pairs broken by DNA helicase

33
Q

What direction can DNA only replicate from?

A

5’-3’ Direction

34
Q

What direction is the Replication fork?

A

Bi-directional

35
Q

What strand orientation forms the Leading strand?

A

3’ to 5’ direction

36
Q

What strand orientation forms the Lagging strand?

A

5’ to 3’ direction

37
Q

What is Step 2 of DNA replication?

A

RNA primer binding

38
Q

How does RNA bind to this fork?

A

Short piece of primer (RNA) binds to 3’end of strand

39
Q

How is the Primer generated?

A

by DNA primase

40
Q

What is Step 3 of DNA replication?

A

Elongation

41
Q

How does Elongation occur during cell replication?

A

DNA polymerase alpha binds to the strand at the site of the primer and adds new comp base pairs during replication

42
Q

After 20 base pairs of replication, what is Elongation taken over by?

A

DNA pol e (epsilon)

43
Q

What does DNA pol e and gamma do?

A

Proofreading of 3’5’ exonuclease activity

44
Q

Why does DNA pol carry out exonuclease activity?

A

Prevent incorporation of incorrect nucleotides

45
Q

What does Elongation and DNA pol result in?

A

Synthesis of 1 continuous replicated DNA strand in the 5’-3’ direction

46
Q

How does DNA replication in the Lagging strand?

A

Multiple RNA primers needed, DNA pol gamma generate comp DNA okazaki fragments to strand between RNA primers

47
Q

What does Replication in Lagging strand do?

A

Discontinues as new fragments are not joined

48
Q

What is Step 4 of DNA replication in both strands?

A

Termination

49
Q

How does Termination occur in DNA replication?

A

RNA primers degraded and filled by action of RNAse H and DNA POL gamma

50
Q

What component of DNA joins any breaks in both strands?

A

DNA ligase

51
Q

What does DNA ligase do?

A

Joins any breaks to generate continuous double stranded DNA

52
Q

What is a Genome?

A

Total DNA in a cell (replicates in 8 hours)

53
Q

Where can DNA replication occur?

A

At mutiple sites with multiple origins of replication with forks in opposite directions (replication bubbles)

54
Q

What happens with the Inheritance of histones after replication?

A

Histones are removed in front of the replication bubble

55
Q

What happens to Histones 3 &4?

A

H3/4 remain intact adjacent to DNA after synthesis - New H3/4 cores bind followed by H2A&B

56
Q

What is Epigenetics?

A

Heritable changes in phenotype cell behaviour or gene expression causes by changes in DNA base that control activity of genes

57
Q

What are 2 examples of Epigenetics?

A

Histone modifications - acetylation of Lys

DNA modificationa - methylation of cytosine

58
Q

What does Epigenetic modifications alter?

A

Chromatin structure to control accessibility of transcription factors

59
Q

What can Epigenetic marks be altered by?

A

Enviromental stimuli such as smoking and nutrition

60
Q

What did the Dutch Famine 1944 show in Epigenetics?

A

First date to show early life enviromental coniditions can cause epigenetic changes that persis through life

61
Q

What are 3 Applications of DNA replication?

A

PCR , DNA sequencing, Precision medicine

62
Q

What is the Definition of Precision medicine?

A

Influence genetic variation on drug response in patients by correlation gene expression with drug toxicity

63
Q

What does Genomics England aim to do?

A

Sequence 100,00 patients with cancers and rare disorders to produce new capability in genomic medicine for NHS

IMS (53 decks)

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