2a. NUCLEIC ACIDS

Question 1

What is a nucleotide?

Answer 1

The basic building block of nucleic acids

Question 2

Describe the three-part structure of a nucleotide

Answer 2

All nucleotides are made up of phosphate, a sugar and a nitrogenous base

Question 3

Describe the structure of ATP

Answer 3

One ribose sugar, adenine, and three phosphtes

Question 4

Describe which part of the nucleotides form the genetic code

Answer 4

The nitrogenous bases form the genetic code

Question 5

Recall the five DNAnitrogenous bases

Answer 5

Adenine, guanine, cytosine, thymine and uracil

Question 6

Recall which bases are purines, and which are pyrimidines

Answer 6

Purines – adenine and guanine. Pyrimidines – cytosine and thymine

Question 7

Recall the structure of purines

Answer 7

Purines – two ringed structure (hexose and pentose)

Question 8

Recall the structure of pyrimidines

Answer 8

Pyrimidines – one ring structure (hexose)

Question 9

Describe the structure of an RNA nucleotide

Answer 9

A phosphate group, a ribose sugar and a nitrogenous base (either Adenine, Guanine, Cytosine or Uracil)

Question 10

What is the function of mRNA?

Answer 10

Transfers genetic information from the DNA to the ribosomes

Question 11

Describe the structure of a DNA nucleotide

Answer 11

A phosphate group, a deoxyribose sugar and a nitrogenous base (either Adenine, Guanine, Cytosine or Thymine)

Question 12

What is the function of DNA?

Answer 12

To hold the genetic information

Question 13

Describe the difference between ribose and deoxyribose sugars

Answer 13

Deoxyribose has one less oxygen (on carbon 2)

Question 14

Describe three similarities between a DNA and RNA nucleotide

Answer 14

DNA and RNA both contain a pentose sugar, have bases A, C and G, and contain a phosphate.

Question 15

Describe two differences between a DNA and RNA nucleotide

Answer 15

DNA uses thymine whereas RNA uses uracil. DNA contains a deoxyribose sugar, whereas RNA contains a ribose sugar

Question 16

What are the similarities between an ATP nucleotide and a DNA nucleotide?

Answer 16

Both contain a sugar, both contain a nitrogenous base, both contain phosphate

Question 17

What are the differences between an ATP nucleotide and a DNA nucleotide?

Answer 17

ATP contains ribose, whereas DNA contains deoxyribose. ATP only contains adenine, whereas DNA can contain A, C, T & G. ATP contains 3 Pi, whereas DNA only contains one

Question 18

What are the similarities between an ATP nucleotide and an RNA nucleotide?

Answer 18

They both contain a ribose sugar, they both contain a nitrogenous base, and they both contain phosphate

Question 19

What are the differences between an ATP nucleotide and an RNA nucleotide?

Answer 19

ATP only contains adenine, whereas RNA can contain A, U, C & G. ATP contains 3 Pi, whereas RNA only contains one

Question 20

Which two types of nucleotides can polymerise?

Answer 20

DNA and RNA

Question 21

Name the reaction that bonds nucleotides together

Answer 21

Condensation (& polymerisation)

Question 22

What is the molecule called when many nucleotides bond together?

Answer 22

Polynucleotide / Nucleic Acid

Question 23

Name the reaction that breaks polynucleotides down

Answer 23

Hydrolysis

Question 24

Recall complementary base pairing rules in DNA

Answer 24

Adenine & Thymine, Cytosine & Guanine

Question 25

Recall the number of bonds each base pair makes. What type of bonds form?

Answer 25

There are 2 hydrogen bonds between adenine and thymine
There are 3 hydrogen bonds between cytosine and guanine

Question 26

If a DNA molecule has 24% of adenine, calculate the percentage of cytosine, guanine and thymine?

Answer 26

If there is 24% of A there is also 24% of T
100% - 24% – 24% = 52% (C and G)
so there is 52/2 = 26% of G and 26% of C

Question 27

Recall complementary base pairing rules in RNA

Answer 27

Adenine & Uracil, Cytosine & Guanine

Question 28

Describe the structure of an RNA molecule

Answer 28

Small and single stranded (therefore no base pairs and no hydrogen bonds)

Question 29

Describe the structure of a DNA molecule.

Answer 29

DNA is two strands of DNA, held together by hydrogen bonds between the bases

Question 30

In which structural part of a polynuleotide do the phosphodiester bonds exist?

Answer 30

The sugar-phosphate backbone

Question 31

Name the shape of a DNA molecule

Answer 31

Double Helix