Chapter 8, Objective 21: Be able to name the 6 major classes of enzymes. Given one of the following reactions, be able to match it with one of the 6 major classes of enzyme reactions catalyzed: alcohol dehydrogenase, glucokinase, chymotrypsin, aldolases, triosephosphate isomerase, and pyruvate carboxylase.
To restate this objective, be able to match the Enzyme Reaction below with the enzyme catalyzing the reaction, i.e., the Enzyme Name. Be able to match either the Enzyme Reaction or the Enzyme Name with one of the 6 Major Classes of Enzymes (see below). You will not be asked to define the 6 Major Classes of Enzymes but I have added some partial definitions below. Use them if it helps.
Ethanol + NAD+ = Acetaldehyde + NADH = H+
Glucose + ATP = Glucose-6-phosphate + ADP
Polypeptide-CO-NH-polypeptide + H2O = Polypeptide-COOH + Polypeptide-NH2
Fructose-1,6-bisphosphate = Dihydroxyacetone phosphate + Glyceraldehyde-3-phosphate
Dihydroxyacetone phosphate = Glyceraldehyde-3-phosphate
Pyruvate + CO2 + ATP = Oxaloacetate + ADP +Pi
Alcohol dehydrogenase, Fig. 8.14
Glucokinase, Fig. 8.3
Chymotrypsin, Fig. 8.8
Aldolase, , Fig. 8.19
Triose phosphate isomerase, Fig. 8.19
Pyruvate carboxylase, Fig 31.6
6 Major Classes of Enzyme
If it helps, here are the definitions:
Oxidoreductase: Oxidoreductases catalyze oxidation reduction reactions. At least one substrate becomes oxidized and at least one substrate becomes reduced.
Transferase: Transferases catalyze group transfer reactions- the transfer of a functional group from one molecule to another.
Hydrolase: In hydrolysis reactions, C-O, C-N, and C-S bonds are cleaved by addition of H2O in the form of OH- and H+ to the atoms forming the bond.
Lyase: Lyases cleave C-C, C-O, C-N, and C-S bonds by means other than hydrolysis or oxidation.
Isomerase: Isomerases just rearrange the existing atoms of a molecule, that is, create isomers of the starting material.
Ligase: Ligases synthesize C-C, C-S, C-O, and C-N bonds in reactions coupled to the cleavage of high energy phosphate bonds in ATP or some other nucleotide.