Question

which best explains how high temperatures affect enzymes and substrates? a. high temps. 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 temperature denature enzymes and stop them from combining with substrates d. high temps. activate the enzymes and allow additional substrates to be attracted to them. a poison is bonded to the active site of an enzyme. which function is the enzyme most likely unable to perform because of the attachment 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 most enzyme - assisted reactions are a. reversible b. able to take place at any temperature c. exothermic d. endothermic 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:

1. When a poison binds to the active - site of an enzyme, the enzyme is unable to perform its function as the active - site is occupied. This prevents the attachment of the substrate and thus stops the catalysis of the reaction. So for the first question about the poison binding to the enzyme's active - site, the answer is related to the enzyme's inability to function due to the occupied active - site.
2. High temperatures can cause enzymes to unfold (denature). This changes the shape of the active - site and affects the enzyme's ability to combine with the substrate. So high temperatures affect enzymes and substrates by causing enzyme denaturation.
3. Enzyme - assisted reactions are often reversible. This is a key characteristic of many enzyme - catalyzed reactions.
4. Enzymes are not consumed in chemical reactions. They can be used repeatedly in many reactions as long as they are not denatured.

Answer:

1. A. The enzyme is most likely unable to perform because of the attachment of the poison molecule.
2. B. High temperatures cause enzymes to unfold the substrate and affect enzymes and substrates.
3. A. Reversible
4. D. All of the above