AP BIOLOGY

Detailed explanation-1: -Hence, erepsin, trypsin and pepsin are involved in protein digestion.

Detailed explanation-2: -Papain, bromelain, keratinases, and ficin are well-known proteases of plant origin (Mala et al., 1998). All these can be categorized into five major classes: cysteine, serine, aspartic, threonine, and metallo-proteases (Zamyatnin Jr., 2015).

Detailed explanation-3: -Cysteine proteases-using a cysteine thiol. Threonine proteases-using a threonine secondary alcohol. Aspartic proteases-using an aspartate carboxylic acid. Glutamic proteases-using a glutamate carboxylic acid.

Detailed explanation-4: -The correct option is B Erepsin, trypsin, pepsin.

Detailed explanation-5: -Proteases are released by the pancreas into the proximal small intestine, where they mix with proteins already denatured by gastric secretions and break them down into amino acids, the building blocks of protein, which will eventually be absorbed and used throughout the body.