enzyme regulation and inhibition - chem exam 3
Call Kai
Learn
Practice Test
Spaced Repetition
Match
Flashcards
Knowt Play1/32
There's no tags or description
Looks like no tags are added yet.
Name | Mastery | Learn | Test | Matching | Spaced | Call with Kai |
|---|
No analytics yet
Send a link to your students to track their progress
33 Terms
Q: Why is it important that enzymes can be regulated?
A: To control metabolic pathways, conserve energy, and maintain balance (homeostasis)
Q: What is enzyme activation?
A: Increasing enzyme activity
Q: What is enzyme inhibition?
A: Decreasing enzyme activity
Q: What are the four main ways enzyme activity is regulated?
Allosteric control
Feedback control
Covalent modification
Control of enzyme synthesis (induction/repression)
Q: What is an allosteric enzyme?
A: An enzyme regulated by molecules binding at a site other than the active site
Q: Why do allosteric enzymes have multiple subunits?
A: Allows cooperative interactions and regulation
Q: Do allosteric regulators resemble the substrate?
A: No
Q: Do they bind at the same site as the substrate?
A: No, they bind at a different (allosteric) site
Q: What is feedback inhibition?
A: The final product of a pathway inhibits an earlier enzyme
Q: Why is feedback inhibition useful?
A: Prevents overproduction of products
Q: What is a zymogen?
A: An inactive enzyme precursor
Q: Why are enzymes made as zymogens?
A: To prevent damage to cells before activation
Q: What is reversible covalent modification?
A: Temporary addition/removal of groups (e.g., phosphorylation)
Q: What is irreversible covalent modification?
A: Permanent change (cannot be reversed)
Q: What is induction?
A: Turning ON enzyme production
Q: What is repression?
A: Turning OFF enzyme production
Q: What is reversible inhibition?
A: Inhibitor binds noncovalently and can detach
Q: What is irreversible inhibition?
A: Inhibitor binds covalently and permanently inactivates enzyme
Q: How do irreversible inhibitors work?
A: They permanently alter the enzyme (often active site)
Q: What is a competitive inhibitor?
A: A molecule that competes with substrate for the active site
Q: Does competitive inhibition change Vmax?
A: No
Q: Does competitive inhibition change Apparent affinity?
Yes
Q: Can competitive inhibition be overcome?
A: Yes, by increasing substrate concentration
Q: What is a noncompetitive inhibitor?
A: Binds to a different site (not active site)
Q: What does noncompetitive inhibition affect?
A: Decreases Vmax
Q: Can it be overcome by adding more substrate?
No
Q: Key difference between competitive and noncompetitive inhibition?
Competitive: binds active site, can be overcome
Noncompetitive: binds elsewhere, cannot be overcome
Q: Why does increasing substrate overcome competitive inhibition?
A: Substrate outcompetes inhibitor for active site
Q: Do reversible inhibitors bind covalently or noncovalently?
Noncovalently
Q: Do irreversible inhibitors bind covalently or noncovalently?
Covalently
Q: What does a competitive inhibition graph show?
A: Same Vmax, curve shifts right
Q: What does a noncompetitive inhibition graph show?
A: Lower Vmax, curve plateaus lower
Q: Why do allosteric enzymes have multiple binding sites?
A: To allow regulation by multiple molecules and cooperative effects