Organisation: Digestion - Free MCQ Practice Test with solutions, Grade

The main function of bile is to emulsify lipids. This increases the surface area of lipid droplets so as to increase the efficiency of digestion.

The small intestine is the major region of the gut where lipids are broken down. Small amounts of lipases are produced elsewhere in the gut, however.

The active site is the region of an enzyme that binds the substrate molecule, or molecules. The active site has a complementary shape to the substrate.

Bile is released into the duodenum. Bile is produced by the liver and stored into the gall bladder until its release.

Benedict's test is used to detect reducing sugars such as glucose in food. It gives a positive result with glucose, but a negative result with sucrose - the sugar we use in tea and coffee.

Enzyme activity depends on the number of collisions between the enzyme and substrate. An increase in temperature therefore increases the rate of enzyme activity, though high temperatures may denature an enzyme.

Amylase breaks down starch. Amylases are found in the mouth and small intestine.

The main function of the small intestine is the absorption of digested food molecules. The process is efficient because of its very large surface area - about 200 sq m.

The digestion of starch by enzymes begins in the mouth. Here, it is broken down into maltose, a double sugar, but not fully broken down into glucose.

Amino acids are the building blocks of proteins. Twenty types of amino acid are found in proteins in the human body.