Which class of enzyme is designated by a first number of 2 in the Enzyme Commission number?

The class of enzymes designated by a first number of 2 in the Enzyme Commission number corresponds to Transferases. Transferases are responsible for transferring functional groups, such as methyl or phosphate groups, from one molecule to another. This action is crucial in many biochemical processes, including metabolism and signal transduction.

The Enzyme Commission (EC) classification system assigns a unique number to each enzyme based on the type of chemical reaction it catalyzes. The first digit of the EC number indicates the enzyme class:

• The first number "1" represents oxidoreductases (enzymes that catalyze oxidation-reduction reactions).
• The first number "2" identifies the transferases.
• The first number "3" designates hydrolases (enzymes that catalyze the hydrolysis of various bonds).
• The first number "4" indicates lyases (enzymes that cleave bonds by means other than hydrolysis and oxidation).
• The first number "5" corresponds to isomerases (enzymes that catalyze the rearrangement of molecular structures).

Understanding these classifications helps in identifying enzyme functions and their applications in metabolic pathways.