Enzymes/proteins

Question 1

What make up proteins?

Answer 1

Amino acids

Question 2

What is the structure of an amino acid?

Answer 2

Central carbon, amino group, carboxyl group, hydrogen atom and r group

Question 3

What’s the chemical symbol for an amino group?

Answer 3

NH2

Question 4

What’s the chemical symbol for a carboxyl group?

Answer 4

COOH

Question 5

What do amino acids join to make?

Answer 5

Do peptide or polypeptide

Question 6

By what reaction do amino acids join to form a dipeptide?

Answer 6

Condensation reaction

Question 7

What’s the bond between amino acids?

Answer 7

Peptide bond between amino and carboxyl group

Question 8

How can peptide bonds be broken?

Answer 8

By hydrolysis reaction

Question 9

What’s the primary structure of a protein?

Answer 9

Sequence of amino acids in a polypeptide chain

Question 10

What’s the secondary structure of a protein?

Answer 10

The way the chain of amino acids of the polypeptide chain is folded and held by hydrogen bonds between NH group and CO group

Question 11

What’s the tertiary structure of a protein?

Answer 11

Way the whole molecule is folded and held by ionic and disulphides bonds

Question 12

What’s the quaternary structure of a protein?

Answer 12

Number of polypeptide chains linked together

Question 13

What’s the test for a protein?

Answer 13

• add biuret

- turns purple

Question 14

What are enzymes?

Answer 14

Globular proteins, biological catalysts

Question 15

What do enzymes do?

Answer 15

Speed up reactions and lower the activation energy needed to start reactions by weakening bonds when enzyme substrate complex is formed

Question 16

What is an active site?

Answer 16

Place where substrate binds to

Question 17

What does it mean that active sites are specific shapes?

Answer 17

Only substrates that are the right shape will fit into the active site and form enzyme substrate complexes

Question 18

What is the lock and key model?

Answer 18

Active Site does not change shape it’s fixed and is complementary to the substrate

Question 19

What is the induced fit model?

Answer 19

Active site is not complementary; active site changes shape slightly when substrate binds to it

Question 20

What happens if the temp is too high for the enzyme?

Answer 20

Enzyme becomes denatured and the hydrogen bonds are broken meaning the shape of the active site changes

Question 21

What is the effect of the active site changing shape?

Answer 21

Fewer enzyme substrate complexes formed

Question 22

What is competitive inhibition?

Answer 22

Inhibitor is a similar shape to the substrate meaning it binds to the active site but prevents substrate binding so fewer enzyme substrate complexes formed

Question 23

What is non-competitive inhibition?

Answer 23

Inhibitor attaches to the enzyme so the shape of the active site changes so the substrate is no longer complementary so fewer enzyme substrate complexes formed