What are different classes of enzymes ? Explain any two with the type of reactions they catalyse.
What are different classes of enzymes ? Explain any two with the type of reactions they catalyse.
Enzymes are divided into six classes each with 4-13 sub-classes and named accordingly by a four - digit number.
(i) Oxidoreductases/dehydrogenases These enzymes take part in oxidation and reduction or tranfer of e−
S(reduced)+S(oxidised)⟶ S(oxidised)+S(reduced)
(ii) Transferases These enzymes transfer a functional group from one molecule to another (other than hydrogen)The chemical group transfer does not occur in free state.
S−G+S′Transferase⟶S+S′−G
(iii) Hydrolases These enzymes catalyse the hydrolysis of bound like ester, ether, peptide, glycosidic C-C, C-halide, P-N etc.
C12H22O11H2OMaltoseMaltase⟶2C6H12O6Glucose
(iv) Lyases These enzymes causes cleavage, removal of groups without hydrolysis and addition of groups to double bonds or removal of groups producing double bond.
X|C−Y||Clyase⟶X−Y+C=C
(v) lsomerases These enzymes cause rearrangement of molecular structure to effect isomeric changes. They are of three types i.e., isomerases, epimerases and mutases.
Glucose - 6-phosphate Isomerase⟶ Fructose 6-phosphate
(Aldose to ketose group or rice-versa)
Glucose−6−phosphateMulase⟶Glucose−1−phosphate
Xylulose5−phosphateEpimerase⟶Ribulose−5−phosphate
(Change in position of one constiluent or carbon group)
(vi) Ligases are enzymes catalysing bonding of two chemicals with the help of energy obtainedd from ATP resulting formation of bonds such as C-O.C-S.C-N and P-O e.g., pyruvte carboxyl use
Ab+C ⟶ A-C+b
Pyruvric~acid+CO2+ATP+H_2On pyruvate carboxylase⇌Oxaloacetic+ADP+Pi−
Enzymes are divided into six classes each with 4-13 sub-classes and named accordingly by a four - digit number.
(i) Oxidoreductases/dehydrogenases These enzymes take part in oxidation and reduction or tranfer of e−
S(reduced)+S(oxidised)⟶ S(oxidised)+S(reduced)
(ii) Transferases These enzymes transfer a functional group from one molecule to another (other than hydrogen)The chemical group transfer does not occur in free state.
S−G+S′Transferase⟶S+S′−G
(iii) Hydrolases These enzymes catalyse the hydrolysis of bound like ester, ether, peptide, glycosidic C-C, C-halide, P-N etc.
C12H22O11H2OMaltoseMaltase⟶2C6H12O6Glucose
(iv) Lyases These enzymes causes cleavage, removal of groups without hydrolysis and addition of groups to double bonds or removal of groups producing double bond.
X|C−Y||Clyase⟶X−Y+C=C
(v) lsomerases These enzymes cause rearrangement of molecular structure to effect isomeric changes. They are of three types i.e., isomerases, epimerases and mutases.
Glucose - 6-phosphate Isomerase⟶ Fructose 6-phosphate
(Aldose to ketose group or rice-versa)
Glucose−6−phosphateMulase⟶Glucose−1−phosphate
Xylulose5−phosphateEpimerase⟶Ribulose−5−phosphate
(Change in position of one constiluent or carbon group)
(vi) Ligases are enzymes catalysing bonding of two chemicals with the help of energy obtainedd from ATP resulting formation of bonds such as C-O.C-S.C-N and P-O e.g., pyruvte carboxyl use
Ab+C ⟶ A-C+b
Pyruvric~acid+CO2+ATP+H_2On pyruvate carboxylase⇌Oxaloacetic+ADP+Pi−
