Brainscape's Knowledge GenomeTM

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


See full index

Biol 207 > Lecture 3 > Flashcards

Lecture 3 Flashcards

1
Q

What are DNA polymerases?

A

Enzymes that catalyze synthesis of DNA polynucleotide chains

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

What are the general properties of DNA nucleotides?

A
  • Depend on single stranded template DNA

* Can add free nucleotides only to 3’ OH end of an existing polynucleotide

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

What direction can DNA polymerases work?

A

In the 3’ to 5’ direction of the leading (already there) strand continuously. In the 3’ to 5’ strand of lagging strand to produce fragments

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

What is needed before DNA polymerase can work?

A

An RNA primer called primase

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

In what direction is the daughter strand made?

A

In the 5’ to 3’ direction

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

What are the 3 DNA polymerases of E.coli?

A

DNA Polymerase I, II, III

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

What does DNA polymerase III do?

A

Synthesizes most of the DNA during DNA replication

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

What does DNA polymerase I do?

A

Synthesizes some of the DNA during DNA replication. Removes and replaces primers during DNA replication

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

What does DNA Polymerase II do?

A

Not required for replication or growth, functions in DNA repair

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

How are Nucleotides added on to DNA?

A

Through hydrolysis

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

What is bound to the nucleotide before it joins the DNA?

A

3 Phosphates

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

How are the 3 phosphates used in DNA replication?

A

Through hydrolysis they are cleaved off phosphates to use the energy to drive the replication machine to keep replicating

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

What is Primase?

A

Primase is an RNA polymerase that creates short sequences of RNA called primers

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

What do primers provide?

A

A 3’ -OH end for DNA polymerase during replication

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

What removes RNA primers?

A

DNA polymerase

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

What happens to the RNA primer?

A

It is cleaved by endonuclease

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

What proofreads for the DNA polymerase?

A

Polymerase III

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

What is proofreading known as?

A

3’ to 5’ exonuclease activity

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

What does Helicase do?

A

Unwinds DNA, bind one strand and use ATP

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

What direction does Helicase work in?

A

the 5’ to 3’ direction of the strand it is bound to

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

What do SSB’s do?

A

Coat the individual strands of DNA and prevent them from re binding to each other

22
Q

What encodes primase in E.coli?

A

dnaG. It aslo encodes RNA polymerase

23
Q

What are the 3 major modes of DNA rplicastion?

A

Theta Replication
Rolling Circle
Replication of linear DNA in eukaryotes

24
Q

Where does Theta replication occur?

A

Bacteria

25
Q

Where does Rolling Circle replication occur?

A

Viruses, phages, plasmids, and episomes

26
Q

What organism does Replication of Linear DNA. occur?

A

Eukaryotes e.g. humans

27
Q

What is the structure of replication RNA viruses?

A

Many are double or single stranded RNA

28
Q

What causes high mutation rate in viruses?

A

The fact that they encode their own replication factors that lack proofreading

29
Q

What is the process of Theta replication?

A

Because DNA is double stranded and circular DNA unwinds at the replication origin, producing templates for the synthesis of new DNA. A replication bubble forms and this proceeds around the circle. Eventually two new molecules are produced

30
Q

How does Rolling Circle replication work?

A

It is initiated by a break in one of the circular strands. And then the inner strand is used as a template from the 3’ end. Cleavage releases the single stranded linear DNA. The linear DNA serves as a template for a complementary strand

31
Q

What slows down replication in humans?

A

Nucleosomes and other chromosome proteins

32
Q

Why do eukaryotes have multiple origins of replication?

A

To speed up replication of DNA

33
Q

What is RNA Primer removed by on the lagging strand?

A

Exonuclease activity of DNA polymerase I and is replaced by the same enzyme

34
Q

What seals the discontinuous fragments into a single strand?

A

DNA ligase

35
Q

What carries out the replication on the leading strand?

A

DNA polymerase III

36
Q

What carries out the replication on the lagging strand?

A

DNA polymerase I

37
Q

How many origins of replication in Bacteria?

A

One

38
Q

How many replication origins do prokaryotes have?

A

Many, that are long and not well defined

39
Q

What ends replication for circular DNA?

A

Specific proteins building to replication termini called ter

40
Q

What is DNAa?

A

The protein that activates the initiation of DNA replication in bacteria by being the region that pulls DNA to unwind it

41
Q

What does Gyrase do?

A

In DNA replication it removes torsional stress (supercoiling) by creating double strand breaks

42
Q

In what direction does Helicase work in?

A

The 5’ to 3’ direction

43
Q

What does β-clamp do in DNA replication?

A

Keeps DNA Polymerase III attached to DNA

44
Q

What type of overhangs do eukaryotic chromosomes have?

A

3’ overhangs on either end

45
Q

What do Telomeres do?

A

Stabilize the ends of a chromosome

46
Q

How do Telomeres work?

A

They seal the chromosome end with a protein complex, protecting it’s single stranded end

47
Q

What is the WRN protein?

A

A protein that is critical for telomere maintenance and when impaired, causes Werner Syndrome

48
Q

What do Telomeres contain?

A

Long simple repeat sequences

49
Q

What synthesizes Telomeres?

A

Telomerase

50
Q

How does Telomerase work?

A

It uses RNA to extend the 3’ overhang of DNA which gives room for primase to come in and insert RNA which then allows polymerase to fill in the rest of the DNA

51
Q

Where is Telomerase active?

A

In germ cells

52
Q

What does Telomerase need to work?

A

A 3’ -OH end to synthesize DNA. This is provided by the 3’ overhang

Biol 207 (14 decks)

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