Brainscape's Knowledge GenomeTM


Top Flashcards (Certified)
All Flashcards

General Biology 1 > Chapter 14 > Flashcards

Chapter 14 Flashcards

(57 cards)

Start Studying
1
Q

Why did biologists in the early 1900’s think that proteins were the source of genetic information?

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

What is meant by polarity in reference to DNA?

A

Refers to directional orientation of DNA strands. DNA is read in the 5-3 direction and 3-5 direction

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

What are Chargaff’s rules?

A
  1. Amount of adenine always equals amount of thymine (A = T); amount of guanine always equals cytosine (G = C)

2.

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

What was Rosalind Franklins contribution to understanding the structure of DNA?

A

Used X-ray crystallography to study 3D structure of DNA

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

Describe the antiparallel configuration of the double helix.

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

Why is it important that DNA polymerases also have nuclease activity?

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

T or F. Both DNA and RNA polymerases require primers

A

False. Only DNA polymerase requires primers

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

In what way is DNA replication semidiscontinuous?

A

Replication in leading strand is always continuous; Lagging strand has to be replicated in small chunks - requires many primers

This together makes DNA replication semicontinuous

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

Why is the lagging strand replicated differently than the leading strand?

A
  • More complicated because its discontinuous
  • Primase is needed to make primers for each Okazaki fragment
  • Okazaki fragments must be stitched together
How well did you know this?
1
Not at all
2
3
4
5
Perfectly
10
Q

What is an Okazaki fragment?

A

DNA fragment synthesized on lagging strands

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

How does the sliding clamp and clamp loader work - what is their function?

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

Why is replication of eukaryotic chromosomes more complicated than prokaryotic? And how do eukaryotic cells overcome these challenges?

A

Eukaryotes:
- multiple replication origins on each chromosome
- multiple, linear chromosomes

Prokaryotes:
- one origin of replication
- singular, circular chromosome

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

What DNA polymerases are involved in eukaryotic replication? How are they different than those in prokaryotes?

A

DNA pol epsilon - synthesizes leading strand

DNA pol delta - synthesizes the lagging strand

  • Greater division of labor in eukaryotes
How well did you know this?
1
Not at all
2
3
4
5
Perfectly
14
Q

Compare specific and non-specific repair mechanisms.

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

What is a thymine dimer, and how are they repaired?

A

Thymine dimer - adjacent thymines become covalently linked

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

How does excision repair work?

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

A-T base pair

A

Adenine (A) can form two hydrogen bonds with thymine (T)

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

G-C base pair

A

Guanine (G) can form three hydrogen bonds with cytosine (C)

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

T or F: Strands are indentical

A

F: Strands are NOT identical; they are COMPLEMENTARY

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

What are the components of DNA replication?

A

Template – the parent DNA strand

Polymerase enzyme - does the actual ‘copying’

Nucleotides – the building blocks to make the new strand

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

What are the three stages of DNA replication?

A

Initiation – start of replication

Elongation – where the building blocks are added

Termination – replication ends

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

DNA polymerase

A

class of enzymes that all synthesize DNA

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

What are the common features that DNA polymerases share?

Study These Flashcards
A
  • add new bases to 3’ end of existing strands
  • synthesize in 5’-to-3’ direction
  • require a primer of RNA
24
Q

RNA polymerase

Study These Flashcards
A

enzyme that synthesizes primers

25
the origin of replication (oriC)
spot on chromosome where replication begins
26
Initiation of DNA replication in prokaryotes begins when:
1. DnaA (protein) binds to oriC 2. Causes the two strands at this region to separate 3. Allows the enzymatic machinery for replication to attach to a strand, begin replication 4. After initiation, replication proceeds bidirectionally --> elongation
27
Nuclease
enzyme that breaks down nucleotides
28
Endonuclease
enzymes capable of cleaving phosphodiester bonds between nucleotides internally in a DNA strand
29
Exonuclease
enzymes capable of cleaving phosphodiester bonds between nucleotides located at the ned of a DNA strand
30
DNA Pol I, II, and II have ________ activity
exonuclease
31
DNA polymerase I
acts on lagging strand to remover primers and replace them with DNA
32
DNA polymerase II
Involved in DNA repair
33
DNA polymerase III
Main replication enzyme
34
Helicase
enzyme that unwinds DNA (breaks hydrogen binds that hold nucleotides together)
35
T or F: Helicase breaks phosphodiester bonds when unwinding DNA
F: Helicase breaks HYDROGEN BONDS
36
Topoisomerase
enzyme that relieves torsional strain caused by unwinding
37
DNA gyrase
topoisomerase involved in DNA replication
38
Leading strand
Continuous strand
39
Lagging strand
discontinuous strand uses multiple primers
40
Replication fork
Where DNA synthesis is occurring
41
DNA primase
RNA polymerase that makes the necessary primers
42
Primers
Short stretched of RNA (10-20 bp)
43
Leading strand synthesis
44
Lagging strand synthesis
Primase needed to make primers for each Okazaki fragment DNA Pol I: removes primers and replaces them with DNA DNA Pol III: synthesizes lagging strand DNA ligase: Joins Okazaki fragments
45
Replicons
areas where replication is occurring on eukaryotic chromosomes
46
DNA pol a (and primase)
Involved in priming
47
DNA pol e (epsilon)
synthesize leading strand
48
DNA pol d (delta)
synthesizes lagging strand
49
Mutagen
Agent that induces changes in DNA (mutations)
50
Specific repair
51
Nonspecific repair
52
Mismatch repair (MMR)
removes incorrect bases and replaces them with correct base by copying template strand
53
Thymine dimer
Adjacent thymines become covalently linked together
54
What occurs during photorepair
UV light causes damage to DNA Causes thymine dimers
55
Photolyase
enzyme that binds to thymine dimers
56
Excision repair
Damaged region is removed (excised) then replaced by DNA synthesis
57
What are the three steps in excision repair?
1. Recognition of damage 2. Removal of damaged region 3. Synthesis using undamaged strand as template

General Biology 1 (13 decks)

Brainscape helps you reach your goals faster, through stronger study habits.
© 2025 Bold Learning Solutions. Terms and Conditions