SU 5.4/5.5

Non-protein molecules that permanently assist in enzymatic functions are –

• Cofactors

• Activators

• Coenzymes

• Intermediates

The reactant molecules in enzymatic reactions are the —

• Specificity

• Product

• Active site

• Substrate

Proteases are enzymes that break the bonds between amino acids.

• True

• False

If inhibition is to be competitive, which of the following must be true?

• There must be more than one binding site

• The substrate and the inhibitor must be similar

• The reaction cannot require a cofactor

• The reaction must be endergonic

Increasing the temperature increases the rate of an enzyme reaction. Above critical temperature, the reaction stops. Y?

• The concentration of reactants drop

• The enzymes have all been consumed in the reaction

• The increase in temperature alters the pH

• The polypeptide chains in the enzyme denature

Study this metabolic pathway: Which of the following statements is NOT correct? (E represents enzymes)

• C is the substrate for enzyme E1 and D is the product

• A is the substrate for enzyme E1 and B is the product

• Enzyme E2 can catalyze the substrate B but not A, C and D

• B is the product formed by enzyme E1 but the substrate for enzyme E2

Sarin, a nerve gas, was released into the Tokyo subway system in 1995 injuring more than 5000 people. Sarin blocked the active sites of the enzyme acetylcholinesterase, which degrades acetylcholine, a compound that causes muscles to contract. Over-contraction of muscles can cause asphyxiation.

What is the biological term for this nerve gas?

• Activator

• Inhibitor

• Cofactor

• Coenzyme

All enzymes are proteins.

• True

• False