Enzymes and Energy Reactions Assessment

What is the primary role of enzymes in biological reactions?

• To increase the energy of activation
• To decrease the energy of activation
• To convert kinetic energy into potential energy
• To provide energy for endergonic reactions

Which of the following best describes a substrate?

• The site on the enzyme where the reaction occurs
• The energy required to start a reaction
• The molecule upon which an enzyme acts
• The product of an enzymatic reaction

What is an active site?

• The area where substrates are converted into products
• The location where inhibitors bind to an enzyme
• The energy required to activate a substrate
• The specific region of an enzyme that binds to the substrate

Endergonic reactions are characterized by which of the following?

• Energy is released as the reaction proceeds
• Energy is absorbed from the surroundings
• No energy change occurs
• The reaction is spontaneous

Exergonic reactions result in:

• The conversion of kinetic energy into potential energy
• The release of energy to the surroundings
• The absorption of energy from the surroundings
• A decrease in entropy

What does kinetic energy refer to in the context of molecules?

• The energy stored in chemical bonds
• The energy required to break a chemical bond
• The energy of motion of molecules
• The energy lost as heat in reactions

Which of the following is an example of potential energy in biological systems?

• ATP molecules
• Heat released during metabolism
• Movement of molecules across a membrane
• Light energy absorbed by chlorophyll

The energy of activation is best described as:

• The minimum energy required to initiate a chemical reaction
• The total energy released by a chemical reaction
• The energy stored in reactants
• The energy required to break product bonds

In a metabolic pathway, reversible inhibition occurs when:

• An inhibitor permanently alters the enzyme
• An inhibitor binds temporarily to the enzyme
• The enzyme is activated by the substrate
• The substrate is permanently altered

Irreversible inhibition of an enzyme can be caused by:

• Competitive inhibitors
• Non-competitive inhibitors
• Covalent bond formation between inhibitor and enzyme
• Substrate saturation