BIOLOGY 3.8 DIGESTION

Question 1

Digestion is the process by which complex food molecules (like starch, proteins and lipids) are broken down into simple soluble forms that can be absorbed and used by the body. It involves mechanical processes like chewing and churning. It also involves chemical processes using enzymes and takes place in the digestive system starting from the mouth and ending at the anus.

Question 2

Mechanical - when we take the food in our mouth, we chew it to rearrange its physical state/from (especially if it is a solid - which is not easy to swallow). By grinding the food, we can increase the surface area (by changing the lumps of food into a paste) which is easier for enzymes to enter it

Question 3

Mechanical digestion is the physical process of breaking down food into smaller pieces without changing its chemical structure. It includes actions like chewing or churning our food in the stomach. This helps to increase the surface area of the food for enzymes to work more efficiently during chemical diguestion.

Question 4

Chemical digestion is done by enzymes, which are released into our saliva (the enzymes remain into our saliva). Enzymes help us to break down the food - they are present in digestive juices - one of its main jobs (e.g. saliva because it contains enzymes)

Question 5

Digestion in our mouth is mechanical. It is done by teeth which chews, bites or grinds to change its state to a paste form (physical change from solid - paste).