Enzymes Flashcards
What are enzymes?
They are catalysts that increase the reaction rate without altering the equilibrium of the reaction.
What are the key features of active sites?
They have a complementary shape to the substrate, and substrates are bound to form enzyme-substrate complexes.
What does 1 unit equal?
The amount of enzyme that produces 1 umol of product per minute under standard conditions.
What happens if you double the concentration of enzyme?
The rate of reaction doubles as the rate of an enzyme catalysed reaction is proportional to the concentration of the enzyme
What is the affinity when the Km is low?
High affinity as you only require a low concentration of substrate.
What is the affinity when Km is high?
Low affinity as you require a high concentration of substrate.
What’s the effect of competitive inhibition on Km and Vmax?
Km increase as more substrate is required to reach 1/2 Vmax.
Effect of non-competitive inhibition on Km and Vmax.
The Km is unaffected and Vmax decreases.
What is a competitive inhibitor?
Binds at active site and reduces the proportion of enzyme-substrate complexes.
What is a non-competitive inhibitor?
Binds at an allosteric site and decreases the concentration of functional enzymes.
