DNA, RNA & DNA Replication 3.1.5

Question 1

What is DNA? (2)

Answer 1

Deoxyribonucleic acid (1)

Stores genetic infon (1)

Question 2

What is RNA? (2)

Answer 2

Ribonucleic acid (1)

Transfers genetic info from DNA to ribosomes (1)

Question 3

What are nucleotides? (1)

Answer 3

Monomers of DNA and RNA (1)

Question 4

What is a nucelotide made of? (3)

Answer 4

Phosphate group (1)

Nitrogen containing organic base (1)

Pentose sugar (1)

Question 5

The Pentose sugar in a DNA nucleotide is called ___________ (1)

The sugar and the phosphate group stay the same but the ____ can vary? (1)

The 4 possible bases in DNA are _ _ _ _ (1)

Answer 5

deoxyribose (1)

base (1)

A T C G (1)

Question 6

The Pentose sugar in an RNA nucleotide contains a ______ _____ (1)

The sugar and the phosphate group stay the same but the ____ can also vary? (1)

_ replaces _ as a base (1)

Answer 6

ribose sugar (1)

bases (1)

U T (1)

Question 7

What is a polynucleotide? (1)

Answer 7

polymer of nucleotides (1)

Question 8

How are the nucleotides joined? (2)

Answer 8

Condensation reactions (1)

between the phosphate group of one and nucelotide and sugar of another (1)

Question 9

What is the phosphodiester bond made up of? (1)

Answer 9

phosphate group and 2 ester bonds (1)

Question 10

What is the sugar-phosphate backbone? (1)

Answer 10

chain of sugars and phosphates (1)

Question 11

What are 2 polynucleotide strands joined together by? (1)

Answer 11

hydrogen bonding between bases (1)

Question 12

What is complimentary base pairing? (1)

Answer 12

Each base can only join onto 1 specifc base (1)

Question 13

Which bases pair together? (2)

Answer 13

A & T (1)

C & G (1)

Question 14

If A pairs with _ and C pairs with _ there are always _____ amounts of _ and _ in a DNA molecule

Answer 14

T

G

equal

A

C

Question 15

How many hydrogen bonds are there between A and T? (1)

Answer 15

2 (1)

Question 16

How many hydrogen bonds are there between C and G? (1)

Answer 16

3 (1)

Question 17

What is the structure of a DNA double helix? (2)

Answer 17

2 antiparallel polynucleotide strands (1)

twist (1)

Question 18

Who determined the double-helix structure? (1)

Answer 18

Watson and Crick (1)

Question 19

Is RNA longer or shorter than DNA? (1)

Answer 19

shorter (1)

Question 20

What are the 4 main differences between between DNA and RNA? (4)

Answer 20

DNA = double-stranded RNA = Single-stranded (1)

DNA = Deoxyribose sugar RNA = Ribose sugar (1)

DNA = A T C G RNA = A U C G (1)

DNA = Long RNA = Short (1)

Question 21

Before a cell divides, what does DNA do? (1)

Why? (1)

Answer 21

Replicates itself (1)

Each new cell will have full DNA amount (1)

Question 22

What is semi-conservative replication? (1)

Answer 22

Half of strands in each new DNA molecule are from original DNA molecule (1)

Question 23

What does semi-conservative replication allow for? (1)

Answer 23

genetic continuity (between generations of cells) (1)

Question 24

Recall the process of semi-conservative replication? (8)

Answer 24

1. Enzyme DNA helicase breaks H bonds between 2 polynucleotide DNA strands
2. Helix unwinds into 2 single strands
3. Each original strand acts as template for new strand
4. Complimentary base pairing means free-floating DNA nucleotides are attracted to their complimentary exposed bases on each orginal template strand
   - A & T and C & G
5. Condensation reactions join nucleotides of new strand together
6. Enzyme DNA polymerase catalyses the reaction
7. H bonds form between bases on original and new strands
8. Eaxh new DNA molecule contains one strand from original DNA molecule and one new strand

Question 25

What does ‘antiparallel’ mean? (in DNA helix) (1)

Answer 25

strands run in opposite directions (1)

Question 26

Which of 3’ or 5’ end is the active site of DNA polymerase only complimemtary to?

What does this mean?

Answer 26

3’ end

enzyme can only add nucleotides to new strand at 3’ end

Question 27

Which direction is the new strand made in?

Answer 27

5’ to 3’ direction