According to recent estimate, a lysosomes may contain up to 40 types of hydrolytic enzymes. They include proteases, nucleases, glycosidases, lipases etc. All lysosomal enzymes are acid hydrolases and optimaly active at pH 5. The mitochondria contain enzymes for oxidation of food material. During the oxidation of food, large amount of energy is released which synthesize ATP. The smooth ER contains enzymes of lipid synthesis and sterol metabolism. The Golgi body contain glycosyl transferase, acid phosphatases and kinases etc, in animal cell.