Classification of enzymes

6 types of enzymes

1. 1. Oxidoreductases
• are involved in redox reactions
•Eg.
Dehydrogenase (removal of hydrogen)
Oxidase (add oxygen to hydrogen ,forming water)

2. 2. Transferases
•They transfer a group of atoms
form one molecule to another
•General equation :
A-X + B ↔ BX + A
•Eg. :
transaminase (transfer amino
group from one molecule to
another)
phosphotransferase ( transfer
of phosphate group)

3. 3. Hydrolases
•catalyze hydrolysis of substrate by addition of
water
•General equation :A-X + H
2
O ↔ X-OH + HA
•Eg. :
maltase ( maltose broken to 2 glucose)
lipase (lipid broken to fatty acid and glycerol)

4. 4. Lyases
• breaks chemical bonds without adding water
•General equation : A-B → A=B + X-Y
•Eg.,
decarboxylases ( remove carboxyl group from
respiratory substrates to release carbon
dioxide)

5. 5. Isomerases
• catalyzes conversion of one isomer to
another by transferring a group of atoms from
one molecule to another

6. 6. Ligases
•catalyzes the synthesis of new chemical bonds,
using ATP
•Eg.,
DNA ligase is involved in DNA synthesis

7. 6. Ligases
•catalyzes the synthesis of new chemical bonds,
using ATP
•Eg.,
DNA ligase is involved in DNA synthesis