What type of enzyme are caspases classified as?

Caspases are primarily classified as proteases, which are enzymes that break down proteins by hydrolyzing peptide bonds. In the context of apoptosis (programmed cell death), caspases play a critical role by cleaving specific protein substrates that lead to cellular dismantling and death. They are involved in both the extrinsic and intrinsic pathways of apoptosis, thereby ensuring that the process of cell death is regulated and occurs in a controlled manner.

Proteases like caspases can be further categorized as cysteine proteases because they use a cysteine residue in their active site to perform proteolytic cleavage. This specificity allows caspases to target specific proteins during apoptosis, which is essential for the proper execution of this process.

The other enzyme classifications listed do not apply to caspases. Oxidoreductases are enzymes that catalyze oxidation-reduction reactions, metalloenzymes require metal ions for their activity, and transferases transfer functional groups from one molecule to another. Hence, none of these classifications fit the role and function of caspases as well as the classification of proteases does.