Question

q1. which best explains how high temperatures affect enzymes and substrates? a. high temps. increase the substrate concen - tration and cause enzymes to be produced b. high temperatures unfold the substrate and allow enzymes to combine with them c. high temperatures denature enzymes and stop them from combining with substrates d. high temps. activate the enzymes and allow additional substrates to be attracted to them q2. most enzyme - assisted reactions are a. reversible b. able to take place at any temperature c. exothermic d. endothermic q3. a poison is bonded to the active site of an enzyme. which function is the enzyme most likely unable to perform because of the poison molecule? a. the release of stored chemical energy b. the catalysis of the reaction with the substrate c. the supply of activation energy for a reaction d. the donation of electrons to the substrate q4. enzymes are not consumed in chemical reactions. what does this mean? a. enzymes are not denatured b. enzymes are not used up in a reaction c. enzymes can continue to be used in many reactions d. all of the above

Explanation:

• Q1: High temperatures cause enzymes to unfold (denature), disrupting their function. High substrate concentration doesn't directly counter - act the effect of high temperature on enzymes. High temperatures don't allow enzymes to combine with substrates as they denature the enzymes. High temps don't activate enzymes but rather damage them. So the answer is B as high temperatures cause enzymes to unfold.
• Q2: Most enzyme - assisted reactions are reversible. Enzyme - assisted reactions can be exothermic or endothermic and are not able to take place at any temperature due to enzyme temperature - sensitivity. So the answer is A.
• Q3: A poison bonded to the active site of an enzyme makes the enzyme unable to perform its function because the active site is occupied and cannot bind to the substrate. The poison doesn't affect the release of stored chemical energy in the substrate directly, nor does it directly affect the supply of activation energy or the donation of electrons to the substrate. So the answer is A.
• Q4: Enzymes are not consumed in chemical reactions. They can be used repeatedly in many reactions as long as they are not denatured. So all of the statements A (not denatured), B (not used up), and C (can continue to be used in many reactions) are correct. The answer is D.

Answer:

Q1. B. High temperatures cause enzymes to unfold
Q2. A. Reversible
Q3. A. The enzyme is unable to perform because the attachment of the poison molecule to the active site of the enzyme
Q4. D. All of the above