Many proteins are enzymes

Question 1

What are enzymes

Answer 1

catalyses a reaction by lowering the activation energy so rate of reaction increases.

Question 2

Whats the induced fit model

Answer 2

before a reaction enzyme active site is not completely complementary to substrate. However the active site changes as substrate binds to it and this forms enzyme substrate complexes. This distorts the bonds in substrate leading to a reaction.

Question 3

How are enzymes specific

Answer 3

they have a specific shaped tertiary structure and active site. This is because the sequence of amino acids( primary structure) determines tertiary structure. Active site is complementary to a specific substrate enabling only this substrate to bind to active site to form enzyme substrate complexes.

Question 4

Factors effecting rate of reaction

Answer 4

Temperature
enzyme concentration
substrate conc
pH

Question 5

How does temp effect rate of reaction

Answer 5

increasing temp up to optimum increases the rate of reaction. This is because there is an increase in kinetic energy. This leads to more successful e-s collisions and E-S complexes. However if you go above the optimum temp rate of reaction falls as enzyme is denatured as tertiary structure and active site changes shape. This is because the hydrogen and ionic bonds break. So fewer e-s complexes and collisions.

Question 6

Importance of enzymes being proteins

Answer 6

Proteins are very important in forming enzymes as the sequence of amino acids of the polypeptide chain determines the primary structure which then determines the tertiary structure. These are very important as they allow enzymes to be specific. Without enzymes the rate of reaction would be very slow and less e-s complexes would be formed and this has a big effect on the digestive system as it heavily relies on enzymes breaking down molecules into smaller digestible ones. For example exopeptidases Hydrolyse peptide bonds at the ends of protein molecules, Removing a single amino acid