Catalysis Flashcards
What are the 6 classes of enzymes?
- Oxidoreductases
- Transferases
- Hydrolases
- Lyases
- Isomerases
- Ligases
What is the function of oxidoreductases? What is the class number?
Catalyze redox reactions. Class 1
What is the function of transferases? What is the class number?
Catalyze group transfer reactions (phosphates, methyls). Class 2
What is the function of hydrolases? What is the class number?
Catalyze hydrolysis reactions. Class 3
What is the function of lyases? What is the class number?
Catalyze elimination reactions, bond cleavage. Class 4
What is the function of isomerases? What is the class number?
Catalyze molecule rearrangement. Class 5
What is the function of ligases? What is the class number?
Catalyze condensation reactions, bond formation. Class 6
What does each number represent in the enzyme commission number?
First number is the class, second is the subclass, third is type within the subclass, fourth is the enzyme number
Which class of enzymes catalyzes a reaction that uses NAD+ or another cofactor?
Oxidoreductases
Which enzyme class is lactate dehydrogenase part of? What does it do?
Oxidoreductases. It oxidizes lactate into pyruvate
Which enzyme class is alanine transamininase part of? What does it do?
Transferases. It moves an amine group from alanine to alpha-ketoglutarate
Which enzyme class are kinases in?
Transferases
Which enzyme class is pyrophosphatase part of? What does it do?
Hydrolases. It breaks a pyrophosphate into two phosphates
Which enzyme class is pyruvate decarboxylase part of? What does it do?
Lyases. Breaks pyruvate into acetaldehyde and CO2
What trait will be in the products of a reaction catalyzed by a lyase?
Double bond or a ring
What is a lyase working in the opposite direction called?
Synthase
Which enzyme class is alanine racemase part of? What does it do?
Isomerases. It changes the chirality of alanine
Which enzyme class is glutamine synthetase part of? What does it do?
Ligases. It uses ATP and NH4+ to convert glutamate into glutamine
Which class of enzymes always requires energy input?
Ligases
Which enzyme class is most common?
Hydrolases
Which enzyme class is the least common?
Ligases
What will the enzyme commission number be for an enzyme with multiple catalytic domains?
Each domain has its own number
How do enzymes lower the activation energy of a reaction?
The reaction mechanism is rerouted through multiple smaller steps