(main)[8]
Fill in the enzyme sentences by entering an appropriate word or phrase in each blank. Enzymes take part in chemical digestion, producing small [BLANK] molecules that can pass into the blood. Two protease enzymes are pepsin and trypsin. Pepsin is made by the [BLANK] and works best in acidic conditions. Such conditions are produced by the secretion of [BLANK], which gives the optimum pH for pepsin activity and also destroys harmful [BLANK]. The [BLANK] makes trypsin, which digests protein in [BLANK] pH conditions. These conditions are produced by a substance called [BLANK], which neutralises gastric juices and also plays a key part in the [BLANK] of fats and oils.