✅2 - Nucleic Acids

Question 1

What are individual nucleotides made up?

Answer 1

• a pentose sugar
• a phosphate group
• a nitrogen containing organic base (C,T,U,A,G)

Question 2

How are the 3 components joined?

Answer 2

As a result of condensation reactions

Question 3

What is a phosphodiester bond?

Answer 3

The bond between the deoxyribose of one mononucleotide and the phosphate group of another

Question 4

A=

Answer 4

Adenine

Question 5

T=

Answer 5

Thymine

Question 6

G=

Answer 6

Guanine

Question 7

C=

Answer 7

Cytosine

Question 8

U=

Answer 8

Uracil

Question 9

What is a dinucleotide?

Answer 9

When two nucleotides are by need together

Question 10

What is a polynucleotide?

Answer 10

The continued linking of mononucleotides forming a long chain

Question 11

What 4 bases does RNA have?

Answer 11

A,C,G,U

Question 12

Describe the structure of RNA:

Answer 12

A single, relatively short polynucleotide chain where the pentose sugar is always ribose.

Question 13

What are the 3 types on RNA involved in?

Answer 13

• transfers genetic information from DNA to the ribosomes
• ribosomes are made up of a type of RNA
• involved in protein synthesis

Question 14

Describe the structure of DNA:

Answer 14

The pentose sugar deoxyribose, making up two strands of polynucleotides, each of which are extremely long and joined by hydrogen bonds

Question 15

What are the complimentary pairs?

Answer 15

A-T

G-C

Question 16

Which are the Purine bases?

Answer 16

Adenine and Guanine

Question 17

Which are the Pyrimidine bases?

Answer 17

Cytosine and Thymine

Question 18

How many bases in mRNA code for an amino acid?

Answer 18

Three, known as a codon

Question 19

What does the order of the codons specify?

Answer 19

The type, number and sequence of the amino acids

Question 20

How is the DNA molecule adapted to carry out its functions?

Answer 20

• it is a very stable structure which rarely mutates
• two separate strands joined only by hydrogen bonds can separate easily during replication
• extremely large molecule which can therefore carry a lot of genetic information
• base pairing leads to the DNA being able to replicate and to transfer information as mRNA

Question 21

Why is DNA a stable molecule?

Answer 21

• the phosphodiester backbone protects the more chemically reactive organic bases inside the double helix
• hydrogen bonds link the organic base pairs forming bridges between phosphodiester backbones. As there are three hydrogen bonds between G and C, the higher the proportion of the bonds, the more stable the DNA