Enzyme Mechanisms Flashcards
What are the different types of enzyme mechanisms
What are Lewis acids and bases
What is general acid catalysis
What is general base catalysis
What is specific acid catalysis
What is specific base catalysis
What is Concerted General Acid-Base catalysis
What is the transition state for the uncatalysed keto-enol tautomerisation
What is an election sink
What are the formal charges when the nucleophile and electrophile start off neutral
What are the formal charges when the electrophile is positive and nucleophile is negative at the start of the reaction
What is the mechanism for Acid-catalysed keto-enol tautomerisation
What is the mechanism for Base-catalysed keto-enol tautomerisation
What is the mechanism for Concerted mechanism of acid/base-catalysed keto-enol tautomerisation
What is the effect of pH on enzyme activity and why (including the interpretation of a bell shaped ph profile
How can pKa values be shifted by the microenvironment in the active site of an enzyme
How can pKa be decreased when a positive charge is near a negative charge in the active site of an enzyme
What is covalent catalysis
What is a group transfer reaction
Covalent catalysis is important for these
How can a group transfer reaction occur via a ternary complex
(a type of covalent catalysis mechanism)
Have can a group transfer reaction occur via a ping pong mechanism
(A type of covalent catalysis mechanism )
How is covalent catalysis important for making the substrate more reactive in a single substrate reaction
How can formation of a schiff base be used to activate carbonyl groups
Give the uncatalysed and catalysed mechanism for acetoacetate decarboxylase (activation of a carbonyl carbon)
What is chemical trapping of enzyme intermediates and what is it used for
What is electrostatic catalysis
Electrostatic catalysis occurs when the enzyme active site stabilizes the transition state of the reaction by forming electrostatic interactions with the substrate. The electrostatic interactions can be ionic, ionic-dipole, dipole-dipole, or hydrophobic interactions.
What are the two classes of metal con requiring enzymes
What are metal ions involved in
Give some examples of redox roles of iron and manganese
How can water be activated
What is catalysis through orientation and proximity effect
What is the difference between an uncatalysed and enzyme catalysed reaction with reference to orientation and proximity effects
What is preferential binding of the transition state
Why are uncatalysed reactions slow
What does a high and low pka mean
High ~ weak acid as Ka is smaller
Low - strong acid
Ka tells you how completely an acid dissociates in aq solution
