2.1.3

Question 1

What’s five elements do you all nucleic acids have?

Answer 1

Carbon
Hydrogen
Oxygen
Nitrogen
Phosphorus

Question 2

What are nucleotides formed of?

Answer 2

• Phosphate
• Pentose sugar
• Nitrogenous base

Question 3

What is the phosphate group?

Answer 3

Acidic inorganic molecule with the formula PO4, and a charge of two minus

Question 4

How are nucleotides linked together?

Answer 4

Through condensation reactions.

Making polynucleotides

Question 5

Where on the pentose sugar is the base and phosphate group joined
?

Answer 5

• Base is attached to the first carbon

- phosphate group is attached to the fifth carbon

Question 6

What is bond is formed between nucleotides?

Answer 6

Phosphodiester bonds

Question 7

Where are the phosphodiester bonds formed when linking the nucleotides together?

Answer 7

The phosphate group at the fifth carbon covalently bonds with the OH group at the third carbon

Question 8

What’s the difference between a deoxyribose sugar and a ribose sugar?

Answer 8

On the second carbon the deoxyribose sugar has one less oxygen than Ribose

Question 9

What are pyrimidines?

Answer 9

-Smaller bases

Single carbon ring structures

Question 10

Give two examples of pyrimidines

Answer 10

Thymine and cytosine

Question 11

What are purines?

Answer 11

-Larger bases

Double carbon ring structures

Question 12

Give two examples of purines.

Answer 12

Adenine and guanine

Question 13

How many hydrogen bonds are formed between complimentary bases?

Answer 13

Thymine and Adenine: two hydrogen bonds

Cytosine and guanine: three hydrogen bonds

Question 14

Why is DNA antiparallel?

Answer 14

Because the two parallel strands run in opposite directions

Question 15

What is complimentary base pairing?

Answer 15

Small pyrimidine always bonds to large purine
A and T
C and G

Question 16

What is ATP?

Answer 16

Adenine triphosphate
Formed of:
-adenine
-ribose
-three phosphate groups

Question 17

How are the phosphate groups in ATP joint?

Answer 17

By two high energy bonds

Question 18

How does ATP become ADP?

Answer 18

It can be hydrolysed to release adenine diphosphate

Question 19

What is the enzyme used to catalyse the hydrolysis of ATP?

Answer 19

ATPase

Question 20

What is produced from the hydrolysis of ATP?

Answer 20

ADP
Pi
30kJ/mol

Question 21

What is semiconservative replication?

Answer 21

Double helix unwinds
Free DNA nucleotides pair up with complimentary bases.
New nucleotides join adjacent nucleotides

Question 22

Why is it called semiconservative?

Answer 22

Because it’s half the same:
One old strand,
One new strand

Question 23

What is DNA helicase used for?

Answer 23

It travels along DNA backbone, catalysing reactions that break hydrogen bonds.
It’s the enzyme that unwind and separates DNA strands

Question 24

What is DNA polymerase used for?

Answer 24

It catalyse the formation of phosphodiester bonds between nucleotides

Question 25

What is mutation?

Answer 25

Incorrect sequence
Not always match exactly
(the DNA)

Question 26

What is the genetic code

Answer 26

DNA that codes for sequence of amino acids