6.4.4: DNA

Question 1

DNA stands for

Answer 1

deoxyribonucleic acid

Question 2

DNA

Answer 2

Contains all the genetic information of an organism

Question 3

DNA is made up of

Answer 3

lots of monomers called nucleotides

Question 4

Nucleotide three components

Answer 4

phosphate group
pentose sugar
base

Question 5

Phosphate group in nucletides

Answer 5

an ion which has a negative charge on one of the oxygen’s

PO2OH2

Question 6

Pentose sugar in DNA

Answer 6

A five carbon sugar which is 2-deoxyribose in DNA

Question 7

Base in DNA

Answer 7

Each nucleotide in DNA contains one of four different bases: adenine, thymine, cytosine and guanine.

Question 8

Basic structure of a nucleotide

Answer 8

a phosphate ion bonded to a pentose sugar bonded to a base

Question 9

Polynucleotide chain

Answer 9

• made up of nucleotides joined together,
• covalent bonds form between the sugar of one nucleotide and the phosphate group of one nucleotide
• sugar-phosphate backbone

Question 10

How is the sugar-phosphate backbone formed

Answer 10

condensation polymerisation

Question 11

DNA structure

Answer 11

Formed from two polynucleotide strands which spiral together to form a double helix structure which is held together by hydrogen bonds

Question 12

Complementary base pairs in DNA

Answer 12

A and T

C and G

Question 13

What is complementary base pairing due to

Answer 13

the arrangement of atoms in the base molecules that are capable of forming hydrogen bonds

Question 14

How many hydrogen bonds between the base pairs

Answer 14

A+T, 2 hydrogen bonds

C+G, 3 hydrogen bonds

Question 15

What does the DNA helix do so complementary base pairs can form?

Answer 15

twist so they are in the right alignment and the right distance apart