AP BIOLOGY

Detailed explanation-1: -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-2: -Two popular proteases that come from plant sources are papain from papayas and bromelain from pineapples. Both of these have been used for their ability to break down proteins for centuries, but as a meat tenderizer, not for health reasons.

Detailed explanation-3: -All known enzymes are proteins. They are high molecular weight compounds made up principally of chains of amino acids linked together by peptide bonds.