Question

q1: which best explains how high temperatures affect enzymes and substrates? a. high temps. and substrates increase the substrate concentration 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 with substrates 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 in a reaction. 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 can denature enzymes (affect their structure and function), and high substrate concentration can increase the rate of reaction until all enzyme - active sites are occupied. Option C is correct as high temperatures denature enzymes and stop them from combining with substrates.
• Q2: Enzyme - assisted reactions can be exothermic or endothermic and can occur at any temperature. They are often reversible. Option D is correct as most enzyme - assisted reactions can be either exothermic or endothermic.
• Q3: A poison bonds to the active site of an enzyme, preventing the substrate from attaching. Option A is correct as the poison's attachment to the active site hinders the enzyme's function.
• Q4: Enzymes are not consumed in chemical reactions. They can be used in many reactions as they are not denatured during normal catalytic cycles. Option C is correct.

Answer:

Q1. C. High temperatures denature enzymes and stop them from combining with substrates.
Q2. D. Endothermic
Q3. A. The poison molecule attaches to the active site of the enzyme, unable to perform its function.
Q4. C. Enzymes can continue to be used in many reactions