Topic 1

Question 1

Describe how the structure if a protein depends on the amino acids it contains

Answer 1

-structure us determined by the position of amino acids/ r group

1- primary structure of aa

2-sec firmed by hydorogen bonding between amino acids

Tertiary formed by interactions of R groups
Create active site in enzyme

Quaternary= more than 1 polypeptide chain

Question 2

Describe how amino acids join to form a poly peptide so there is always HN2 at one end and COOH at the other end

Answer 2

One amine group joins to a carboxyl group to form a peptide bond

So in chain there is free amine group at one end and a free carboxyl group at the other

Question 3

Answer 3

Moved to negative because they are positively charged

Moved at diff distances cause they have diff charge/ mass

2 not 3 spots cause 2 had same charge/ mass

Question 4

The 2ndary structure of a polypeptide is produced by bonds between amino acids
How

Answer 4

Hydrogen bonds between amino acids (between NH and c=O

Question 5

Two proteins have the same number and type of amino acids but different tertiary structures
Explain why

Answer 5

Diff sequence/ order of amino acids
Diff primary structure
From diff hydrogen/ionic/disulphide bonds in diff places

Question 6

Describe how a peptide bond is formed between 2 amino acids to form a di peptide

Answer 6

By 1 condensation reaction
Between amine and COOH
To remove 1 water molecule
To form a peptide bond
Catalysed by a named enzyme

Question 7

Describe how the structure of a protein depends on the amino acid it contains (5)

Answer 7

Question 8

Explain how the active site of an enzyme causes a high rate of reaction

Answer 8

Question 9

Answer 9

Question 10

Describe how the he structure of a protein depends on the amino acid it contains (5)

Answer 10

Structure determined by position of amino acids/R group

Primary structure- number and sequence of aa
Secondary- hydrogen bonds formed between aa form a helix or beta pleated sheet
Tertiary- 3d structure depending on the placement of hydrogen/ionic/disulphide bonds between r groups from aa in pp chain

Creates active site in enzyme

Question 11

Use the diagram and your knowledge of enzymes to explain how sulphanilamide prevents bacteria producing folic acid (3)

Answer 11

Competitive inhibitor
Similar shape to PABA
Binds to AS
Less esc formed cause less PABA binds

Question 12

Explain how the active site of an enzyme causes a high rate of reaction

Answer 12

Lowers activation energy
Induced fit causes AS to change shape
Esc stresss bonds in substrate

Question 13

Answer 13

Enzyme hydrolyses protein into aa
Products are soluble/ can be washed away