DNA and RNA

Question 1

What are the 4 bases in DNA

Answer 1

Adenine, Thymine, Guanine and Cytosine

Question 2

What are the 4 bases for RNA

Answer 2

Adenine, Guanine, Uracil and Cytosine

Question 3

Which bases are Purines

Answer 3

Adenine and Guanine

Question 4

Which bases are Pyrimidines

Answer 4

Uracil, Thymine and Cytosine

Question 5

What are Purines

Answer 5

Double Ring nucleotide bases

Question 6

What are pyrimidines

Answer 6

Single ring nucleotide bases

Question 7

What is the difference in chemical structure between DNA and RNA

Answer 7

RNA has a Hydroxyl (OH) group on 2C whereas DNA only has a Hydrogen (H)

Question 7

What is the difference in chemical structure between DNA and RNA

Answer 7

RNA has a Hydroxyl (OH) group on 2C whereas DNA only has a Hydrogen (H)

Question 8

Which carbon do the nucleotides attach

Answer 8

Carbon 1

Question 9

Which carbon do the nucleotides attach

Answer 9

Carbon 1

Question 10

Which Carbon does the phosphate group attach

Answer 10

Carbon 5

Question 11

What is the structure of Deoxyadenosine Triphosphate (dATP)

Answer 11

Adenine
Deoxyribose Sugar
3x Phosphate

Question 12

What is the Structure of Adenosine Triphosphate (ATP)

Answer 12

Adenine
Ribose Sugar
3x Phosphate

Question 13

In DNA, how do the bases bind

Answer 13

AT (2 hydrogen bonds)

CG (3 hydrogen bonds)

Question 14

What is the structure of DNA (4)

Answer 14

Double-Stranded
Anti-parallel
Complementary
Sugar Phosphate backbone

Question 15

How does Cytosine and Guanine form hydrogen bonds

Answer 15

C/G
H-O
N-H
O-H

Question 16

How does Thymine and Adenine form Hydrogen bonds

Answer 16

T/A
O-H
H-N

Question 17

DNA Replication is …

Answer 17

Semi-conservative

Question 18

How is DNA Replication started (4)

Answer 18

DnaA protein binds and begins the separation of strands
DnaB protein (helicase) further opens strands
Single-stranded binding protein (SSB) prevents the strands from re-joining
Replication can now begin

Question 19

During Replication, which direction is DNA synthesised

Answer 19

5’ to 3’

Question 20

How is DNA synthesised on the Leading Strand

Answer 20

RNA Primer added

DNA polymerase works 5’ to 3’ (towards the replication fork)

Question 21

How is DNA Synthesised in the lagging strand

Answer 21

Multiple RNA primers attached

Okazaki fragments created in a discontinuous synthesis

Question 22

How is DNA polymerase proof read

Answer 22

DNA polymerase 3’ to 5’ exonuclease activity cleaves incorrect nucleotide

Question 23

How does Sanger DNA Sequencing work (6)

Answer 23

Primer binds next to the region of interest
Adds Nucleotide analogue ddNTP to prevent the further synthesis
This results in the formation of extension products (EP)
The EP is separated by Capillary Electrophoresis (CE)
A laser exited the dye-labelled DNA fragments as they pass through a tiny window at the end of the capillary
A software then detects and interprets the dye

Question 24

How does Illumina sequencing work (5)

Answer 24

Large DNA molecules are fragmented Ligated to short adaptors and attached to a surface chamber All four dNTPs are added, with specific dye and terminator one cycle = one nucleotide added = one specific colour process repeated, adding one nucleotide at a time and imaging between

Question 25

How does PCR work (5)

Answer 25

``` Amplification of specific regions from a complex background Denaturation of DNA at 75 DegC Annealing of DNA at 55DegC Extension of DNA with DNA polymerase Steps repeated 25-40 times ```

Question 26

What does describing transcription and translation as coupled mean

Answer 26

They occur in the same compartment at the same time

Question 27

What are the steps in Transcription (4)

Answer 27

DNA is copied to form mRNA 'Cap' (7-methyl guanosine) added to the 5' end of the mRNA RNA is spliced (introns removed) to form mature mRNA Poly A tail added to the 3' end

Question 28

What are the steps in Translation (3)

Answer 28

Mature mRNA enters Ribosome Codon on the mRNA complementary to that of conjugate anticodon on tRNA Amino acids on the tRNA bind to form polypeptide chain

Question 29

What is the Wobble Mechanism

Answer 29

The 3rd base on the codon can pair with multiple bases | Can cause unusual base pairings, such as G-U