All Flashcards
Describe the effect of increasing temperature on enzyme activity.
Initially increases reaction rate due to more collisions, but beyond the optimal temperature, the enzyme denatures and activity decreases.
Describe the effect of pH on enzyme activity.
Each enzyme has an optimal pH. Deviations from this pH can disrupt the enzyme's 3D shape and decrease activity.
Explain how a competitive inhibitor affects enzyme activity.
It binds to the active site, blocking the substrate and reducing the rate of the reaction. Increasing substrate concentration can overcome this inhibition.
Explain how a noncompetitive inhibitor affects enzyme activity.
It binds to an allosteric site, changing the shape of the enzyme and active site, preventing substrate binding and reducing the reaction rate. Increasing substrate concentration will not overcome this inhibition.
Outline the process of enzyme denaturation.
Exposure to extreme temperature or pH causes bonds in the enzyme to break, leading to a loss of 3D structure and function.
Define enzyme.
Biological catalysts (usually proteins) that speed up reactions by lowering activation energy.
What is the active site of an enzyme?
The specific region of an enzyme where the substrate binds and catalysis occurs.
Define induced fit.
The change in shape of an enzyme's active site to better fit the substrate after binding.
What does it mean for an enzyme to denature?
The loss of a protein's 3D structure, leading to loss of function, often caused by extreme temperature or pH.
Define optimal temperature in the context of enzymes.
The specific temperature at which an enzyme exhibits maximum activity.
Define optimal pH in the context of enzymes.
The specific pH at which an enzyme exhibits maximum activity.
What is a competitive inhibitor?
A substance that binds to the active site of an enzyme, blocking the substrate from binding and reducing enzyme activity.
What is a noncompetitive inhibitor?
A substance that binds to a site other than the active site (allosteric site) of an enzyme, changing its shape and reducing its activity.
Compare and contrast competitive and noncompetitive inhibitors.
Competitive: Binds to active site, substrate can't bind, inhibition can be overcome by increasing substrate concentration. Noncompetitive: Binds to allosteric site, changes enzyme shape, substrate can't bind, inhibition cannot be overcome by increasing substrate concentration.
Differentiate between denaturation and inhibition of an enzyme.
Denaturation: Changes the protein's structure, often irreversible. Inhibition: Affects enzyme activity, but does not always change the protein's structure permanently.