Brainscape's Knowledge GenomeTM

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


See full index

IMS- DNA > Structure and Replication > Flashcards

Structure and Replication Flashcards

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

What shape is DNA?

A

Double Helix

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

Guanine is joined to ? by ? Hydrogen Bonds

A

Guanine is joined to Cytosine by 3 Hydrogen Bonds

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

Adenine is joined to ? by ? Hydrogen Bonds

A

Adenine is joined to Thymine by 2 Hydrogen Bonds

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

What are adjacent deoxyribose sugars joined by?

A

Phosphodiester bonds

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

What do Histones do?

A

They DNA to be supercoiled around them and packaged into chromosomes

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

What base is different in RNA?

A

Uracil replaces Thymine

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

Why does RNA form secondary structures?

A

Due to the complementary base pairing between bases on the same single strand

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

How many strands does RNA have?

A

1

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

DNA replication is said to be…

A

Semi-conservative. This is because each new double stranded molecule contains an original strand and a newly synthesised complementary strand.

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

What enzymes are responsible for unwinding DNA?

A

DNA Helicases

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

What stabilise the denature DNA?

A

Single Stranded Binding Proteins

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

What enzyme is responsible for synthesising a short RNA Primer?

A

DNA Primase

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

What enzyme is responsible for carrying out the elongation of the new strand of DNA?

A

DNA Polymerase. This occurs through complementary base pairing to the template strand

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

Which direction is DNA synthesised?

A

5’ to 3’

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

What is needed for the addition of the next nucleotide to initiate replication?

A

A free 3’ OH. This is supplied by the short RNA primer binding.

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

Which DNA Polymerase carries out DNA replication in Eukaryotes?

A

DNA Polymerase III

17
Q

Synthesis requires…

A

A pool of all 3 dNTPs (bases)

18
Q

DNA Polymerase III catalyses…

A

the formation of a new phosphodiester bond.

19
Q

How is the speed of replication increased?

A

The replication fork moves in two directions.

20
Q

What are Okazaki Fragments?

A

Short, newly synthesised DNA fragments that are formed on the lagging template strand during DNA replication. They replace RNA Primers

21
Q

What enzyme replaces RNA Primers with Okazaki Fragments on the Lagging Strand?

A

DNA Polymerase I

22
Q

Which enzyme seals the gap between OKazaki Fragments?

A

DNA Ligase

23
Q

What is the error frequency of nucleotides inserted into the growing DNA strand?

A

1 in 100,000 (10^5)

24
Q

What is the error frequency of the polymerase enzyme’s 3’ to 5’ editing function?

A

1 in 100 (10^2)

25
Q

After a further check for mismatched bases, what is the overall error frequency of DNA replication?

A

1 in 10^9

26
Q

What causes mutation?

A

DNA Damage. This can be due to Radiation or certain chemicals. This are known as mutagens. Most carcinogens are mutagens

27
Q

What types of mutations are there?

A

Base Substitutions. Deletion of bases. Insertion of bases. Rearrangement of bases.

28
Q

Which type of mutations can be described as silent?

A

Substitutions because the triplet code may still code for the same amino acid.

29
Q

A mutation in which type of cell can be inherited?

A

Germ Cell

30
Q

A mutation in which type of cell cannot be inherited but could lead to cancer?

A

Somatic Cell

31
Q

What types of proteins remove damaged bases?

A

Base Excision Repair Proteins. They are specific to specific types of damage

32
Q

What types of proteins remove sections of damaged DNA strands?

A

Nucleotide Excision Repair Proteins. They are less specific and cut out whole sections.

33
Q

After damaged sections removed by either Base or Nucleotide Excision Repair Proteins, how is the DNA repaired.

A

DNA Polymerase I replaces the DNA by copying the intact strand and DNA Ligase seals the gaps.

34
Q

In terms of DNA repair, when might mutations occur?

A

If the repair goes wrong or there is too much damage to repair. This increases the chance of cancer.

35
Q

Which enzyme recognises the irregular presence of Uracil in a DNA strand and removes it?

A

Uracil N-Glycosylase

36
Q

Why may there be Uracil in DNA?

A

Because the deamination of cytosine produces uracil, which base pairs with adenine.

IMS- DNA (1 decks)

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