Session 6: Enzymes Flashcards
What is a transition state?
High energy intermediate the lies between substrate and product.
What is meant by the ‘induced fit’ active site hypothesis?
The active site of an enzyme only forms a complementary shape after binding of the substrate
What is V0?
Initial rate of reaction
What equation predicts that a reaction rate as a function of substrate concentration will have the shape of a rectangular hyperbola?
Michaelis-Menten
Define Vmax
Maximal rate when all enzyme active sites are saturated with substrate.
Define Km
Substrate concentration that gives half the maximal velocity/ affinity of enzyme to the substrate.
What is the affinity for a substrate when Km is low?
High affinity
What is the affinity for a substrate when Km is high?
Low affinity
What plot is used to allow for an easy estimation of Km and Vmax
Lineweaver-Burk plot
How does an irreversible enzyme inhibitor bind?
Covalently bonded
Give an example of an irreversible inhibitor.
Nerve gases e.g. Sarin
How do reversible inhibitors bind to enzymes?
Non-Coventry therefore they can freely dissociate.
What do competitive inhibitors affect?
Km increases
What do non-competitive inhibitors affect?
Vmax decreases
