ENZYMES AS CATALYSTS L10 Flashcards
What is the reaction for oxidoreductases?
oxidation-reduction reaction
What is the reaction for transferases
Transfer of a chemical group
*kinase event
What is the reaction for hydrolases?
Breaking bonds with water
What is the reaction for lyases?
A cleavage reaction NOT using water
What is the reaction for isomerases?
Change of molecular configuration
What is the reaction for ligases?
Joining of two compounds (ex: amino acid residues)
What proteolytic enzymes compromise of the group serine proteases?
Trypsin, Chymotrypsin and Elastase
Name the essential features of an enzyme binding a substrate
- Active site is located in crevice (sm. part of the enzyme)
- Substrate is bound by mult. weak interactions
- Binding is SPECIFIC
- S is positioned to place bonds in correct orientation for manipulation of atoms
What are Serine Proteases?
Proteolytic enzymes that catalyze peptide bond hydrolysis
What is heart of the catalytic macherinery of a serine proteases?
Catalytic Triad (Aspartic Acid, Histidine, and Serine)
What are the steps of enzyme-mediated catalysis for serine proteases?
- Binding of S
- Attack by Ser
- Transition state
- Release of products
Which 2 factors determine which direction a chemical reaction proceeds?
Enthalpy (Change in heat) and Entropy (measure of randomness)
What happens when delta G is negative?
Reaction occurs spontaneously
What happens when delta G is positive?
Reaction cannot occur (no external energy source)
What happens with delta G is 0?
No further work; reaction is in equilibrium
