Key Concepts - Week 12 - Enzymology (CATCH UP TOPIC) Flashcards
Key concept:
Enzyme kinetics measures…?
how fast a reaction goes
Key concept:
Kinetics is…?
measure with a distinct relationship between RATE with SUBSTRATE concentration (Δ[S]) (First order kinetics)
Key concept:
Michaelis-Menten equation describes…?
What is the equation?
enzyme action provided that an ES is reversibly formed
Key concept:
Know your kinetic terminology
Vmax, Km, specific enzyme activity, Kcat etc
Vmax = maximum velocity of an enzymatic reaction can be defined as the rate of the reaction at which the enzyme shows the highest turnover
Km = Michaelis constant
This is usually expressed as the Km (Michaelis constant) of the enzyme, an inverse measure of affinity. For practical purposes, Km is the concentration of substrate which permits the enzyme to achieve half Vmax
Specific enzyme activity = Specific enzyme activity (usually stated simply as ‘specific activity’) is the number of enzyme units per ml divided by the concentration of protein in mg/ml. Specific activity values are therefore quoted as units/mg or nmol/min/mg (if unit definition B is applied).
Kcat = kcat is the first-order rate constant that determines the reaction rate when the enzyme is fully occupied at a saturating concentration of the substrate. kcat/KM is the second-order rate constant that determines the reaction rate when the enzyme is mostly free at a very low concentration of the substrate
Key concept:
Understand the difference between unimolecular; and sequential and non-sequential bimolecular reactions
(See later cards on each one)
Key concept:
Know what actually happens when reactive groups come together at the active site of an enzyme
Differentiate between covalent, acid/base and metal ion catalysis
Study the examples that highlight these catalytic mechanisms
Describe Vmax
Describe specific enzyme activity
Describe Km
Describe Kcat
What is kcat/Km?
What is KI?
Describe Enzyme Kinetics of NON-COMPETITIVE INHIBITORS
Describe Enzyme Kinetics of UNCOMPETITIVE INHIBITORS
Key concept:
What are unimolecular reactions?
What are PSEUDO UNIMOLECULAR reactions?
What are SEQUENTIAL Biomolecular Reactions?
What is ORDERED Sequential Mechanism?
What is an example of ORDERED Sequential Mechanism?
What is RANDOM Sequential Mechanism?
What is an example of RANDOM Sequential Mechanism?
What are NONSEQUENTIAL Biomolecular Reactions?
Key concept:
Know what actually happens when reactive groups come together at the active site of an enzyme
Differentiate between covalent, acid/base and metal ion catalysis
Study the examples that highlight these catalytic mechanisms
Types of catalytic mechanisms:
Key concept:
Know what actually happens when reactive groups come together at the active site of an enzyme
Differentiate between covalent, acid/base and metal ion catalysis
Study the examples that highlight these catalytic mechanisms
General Acid-base catalysis
Key concept:
Know what actually happens when reactive groups come together at the active site of an enzyme
Differentiate between covalent, acid/base and metal ion catalysis
Study the examples that highlight these catalytic mechanisms
ASPARTATE PROTEASES - work via General Acid-Base Catalysis…?
