Quiz8- Bioprocess Chemical Reactions and Catalysts

What is a catalyst?

• A substance that undergoes a permanent chemical change.

• A substance which increases the rate of a chemical reaction without undergoing a permanent change.

• A substance which decreases the rate of a chemical reaction.

• A substance which is consumed completely in a reaction.

What term is used by biochemists to refer to what is commonly known as a reactant?

• Product

• Catalyst

• Substrate

• Intermediate

How are equilibrium concentrations calculated in a reaction involving a catalyst?

• Using the properties of the catalyst.

• Using only the thermodynamic properties of the substrates and products.

• Based on the activation energy of the reaction.

• Using the properties of intermediates.

Which of the following best describes the similarity between synthetic catalysts and enzymes?

• Both have identical reaction mechanisms.

• Both form some sort of complex with the reactant molecules.

• Both are specific to a single reaction.

• Both affect the equilibrium concentrations of a reaction.

Why are most enzymes highly specific in their catalytic activity?

• Due to their three-dimensional conformation that allows the formation of the active site.

• Because of their molecular weight.

• Due to their synthetic nature.

• Because of their reactivity with water.

What is a cofactor in the context of enzymes?

• A substrate that binds to the enzyme.

• A product that is released after the reaction.

• A nonprotein compound that combines with an inactive protein to form a catalytically active complex.

• Another term for enzyme.

Which of the following is NOT a cofactor?

• ATP

• Glucose

• NAD

• FAD

In a catalyzed reaction, what effect does the catalyst have on the activation energy?

• Increases it

• Decreases it

• No effect

• Doubles it

In an uncatalyzed reaction, why is the reaction rate typically low?

• Because the equilibrium is shifted to the left.

• Because the catalyst is absent.

• Due to a high activation energy.

• Due to a low substrate concentration.

Which of the following describes the role of a catalyst in a reaction?

• Changes the standard free energy change of the reaction.

• Increases the equilibrium concentration of products.

• Makes it possible for substrate molecules with smaller internal energies to react.

• Consumes the reactants quickly.