Question

Differentiate between lyases and ligases.

Answer 1

Hint: Molecules made up of amino acids that help in both elimination reactions and hydrolysis reactions in major metabolic pathways in the body for example glycolysis.

Complete step by step answer:
Biochemical reactions are catalyzed by the enzymes’ ligases and lyases. The reaction which involves bond breaking is catalyzed by lyases and reactions which involve the formation of bonds that are catalyzed by ligases.
Lyases form new compounds by breaking the bonds whereas ligases form new compounds by combining the other molecules.

Lyases	Ligases
Bond-breaking reactions are catalyzed by lyases	Bond formation reactions are catalyzed by ligases
Double bonds are formed	Chemical bonds are formed
Elimination reactions are catalyzed by lyases	Hydrolysis reactions are catalyzed by ligases
Lyases act on only one substrate molecule in a reaction	Ligases act on two substrate molecules or two product molecules in a reaction
In glycolysis and Kreb cycle, lyases are used	Ligases are used in the DNA replication process
Lyases are also known as synthases	Ligases are also known as synthetases

Additional information:
- Double bonds are formed by lyases by the elimination of atoms but the bond breakage is neither done by hydrolysis or oxidation.
- Two molecules are formed at the end of the lyase catalyzed reaction, one is substate with a double bond, and the other is an eliminated molecule.
- Deficiency of lyases in the body causes a disorder called lyase deficiency disorder. a patient with this disorder cannot be able to process leucine amino acid.
- For the reactions which are catalyzed by ligases, they require ATP.
- There are about 50 different types of enzymes that belong to the class ligases.

Note: Lyases examples: In glycolysis lyases from glyceraldehyde-3-phosphate and dihydroxyacetone phosphate (DHAP) from fructose 1,6 bisphosphate. Ligases example: DNA ligases that help in the repair of DNA molecules.