Chemical Digestion Lab Report

Biology Form Four Digestion

Digestion is the process by which food is broken down from complex insoluble substances into simple soluble substances. There are two types of digestion – chemical digestion and mechanical digestion. Mechanical digestion involves breaking up large pieces of food into smaller pieces. This provides a large surface area for the action of enzymes on food. There is no change to the chemical composition of food during mechanical digestion. Mechanical digestion occurs in the mouth (mastication) and in the stomach (churning). Chemical digestion involves the action of enzymes. Large insoluble food molecules are broken down into smaller soluble molecules to be absorbed into the blood stream.

The Role of Teeth
Teeth are found embedded in the upper and lower jaws within the buccal cavity. They cut and grind food into smaller pieces before it is swallowed. The grinding is called mastication. Prolonged chewing of the food ensures that a larger surface area is exposed for the activity of enzymes.
Draw a longitudinal section through an canine or molar tooth. Ensure that the drawing is labeled correctly.

How do you take care of your teeth? Why is dental care important?

Chemical Digestion
Buccal Cavity As the food is being chewed/masticated by the teeth in the
This transports blood from the small intestine to the liver. Some glucose is distributed around the body and used during respiration. Excess glucose is stored in the liver or in muscle as glycogen. Amino acids are used to build cell protoplasm and to repair damaged tissues. They are also used to form enzymes and protein in the blood. After absorption most of the fatty acids and glycerol recombine to form fats which enter the lacteals of the lymphatic system. Eventually the fat enters the blood stream and is used for cell membrane