1.3 Enzymes Flashcards
What is an enzyme?
A biological catalyst that speeds up chemical reactions in living organisms.
True or False: Enzymes are consumed in the reactions they catalyze.
False
Fill in the blank: Enzymes are made up of ______.
proteins
What is the active site of an enzyme?
The region where substrate molecules bind and undergo a chemical reaction.
Multiple Choice: Which factor does NOT affect enzyme activity?
Presence of water
What is the role of a substrate in an enzymatic reaction?
The substance on which an enzyme acts.
True or False: Enzymes can work on any substrate.
False
What is enzyme specificity?
The tendency of an enzyme to catalyze only one specific reaction or type of reaction.
Fill in the blank: Enzymes can be denatured by ______.
extreme temperature or pH changes
Multiple Choice: What is the effect of increasing temperature on enzyme activity up to a certain point?
Increases activity until denaturation occurs
What is the term for the maximum rate of reaction an enzyme can achieve?
Vmax
True or False: All enzymes are proteins.
False
What are coenzymes?
Organic molecules that assist enzymes in catalyzing reactions.
Fill in the blank: An enzyme’s activity is often measured in terms of ______.
turnover number
Multiple Choice: Which of the following is NOT a factor affecting enzyme activity?
Type of substrate
What is enzyme inhibition?
A process where a molecule reduces or blocks the activity of an enzyme.
True or False: Competitive inhibitors bind to the active site of an enzyme.
True
What is allosteric regulation?
The regulation of an enzyme’s activity through the binding of molecules at sites other than the active site.
Fill in the blank: The ______ model describes how enzymes and substrates interact.
lock and key
Multiple Choice: What happens to the rate of reaction when substrate concentration is increased?
It increases until the enzyme is saturated.
What is the difference between a holoenzyme and an apoenzyme?
A holoenzyme is an active enzyme with its cofactor, while an apoenzyme is an inactive form without its cofactor.
True or False: Enzymes can catalyze reactions in both directions.
True
What is the effect of pH on enzyme activity?
Each enzyme has an optimal pH at which it performs best.
Fill in the blank: Enzymes lower the ______ of a chemical reaction.
activation energy
Multiple Choice: Which of the following is a common type of enzyme?
Protease
What is a feedback inhibition?
A regulatory mechanism where the end product of a pathway inhibits an earlier step in the pathway.
