A level DNA

Question 1

Degenerative

Answer 1

There is more than one codon that codes for one amino acid

Question 2

Why is DNA universal

Answer 2

The same base triplet codes code for everything

Question 3

Why is DNA non overlapping

Answer 3

The code is read from a fixed point in groups of three bases. If a base is added or deleted it causes a frame shift and every amino acid after this is changed

Question 4

Helicase

Answer 4

Unzips the DNA strand by breaking the hydrogen bonds between the base pairs. so bases are exposed and can be read and replicated

Question 5

Gyrase

Answer 5

Uncoils the DNA strand

Question 6

DNA polymerase

Answer 6

Catalysed formation of new DNA strand by forming phosphodiester bonds

Question 7

Why is DNA semi conservative

Answer 7

There is 1 old strand and 1 new strand

Question 8

Purines

Answer 8

-Adenine and guanine are the two purines.
-they have 2 rings

Question 9

Pyramidines

Answer 9

-Thymine, cytosine, and uracil are the three pyrimidines.
-pyrimidines contain only 1 ring

Question 10

Adenine monophosphate

Answer 10

Contains only one phosphate group, a sugar and a base

Question 11

Adenine diphosphate

Answer 11

Contains two phosphate groups, a sugar and a base

Question 12

Adenine triphosphate

Answer 12

(ATP) contains three phosphate groups, a sugar and a base

Question 13

Phosphate group

Answer 13

Contains one phosphorus double bonded to one oxygen and single bonded to two oxygens

Question 14

Nucleotide

Answer 14

Phosphate group bonded to a sugar and a base

Question 15

What bonds each nucleotide together

Answer 15

Phosphate bonds

Question 16

Direction that DNA is read in

Answer 16

DNA is template is read in the 3’ to 5’ direction however DNA is synthesised in the 5’ to 3’ direction

Question 17

3(prime)’ and 5(prime)’

Answer 17

3’ end has a hydroxyl group attached to the third carbon on the deoxyribose sugar. The 5’ end has it on the 5th carbon

Question 18

DNA ligase

Answer 18

Joins together sections of polynucleotide strands that are being formed on the lagging strand

Question 19

What are atoms bases made from

Answer 19

Nitrogen, hydrogen, oxygen and carbon

Question 20

measleson stahl

Answer 20

experiment with light and heavy DNA

Question 21

what proteins prevent reanealing of DNA strands during respiration

Answer 21

single stranded binding proteins