Download Year 8 Digestion Objectives

Y8 Digestion Learning Objectives
Pupils should be able to:
1. recall the three food groups- proteins, fats and carbohydrates
2. identify the main food tests: starch – iodine solution goes black-blue, glucose –
Benedict’s + heat gives orange precipitate, fat dissolves in ethanol then milky
emulsion with water, protein – purple solution with Biuret’s + Sodium Hydroxide.
3. recall the concept of a balanced diet
4. know that feeding consists of ingestion, digestion, absorption and egestion
5. explain that starch, protein and fat molecules are digested into smaller soluble
molecules so that they can be absorbed into the blood.
6. identify the structure of teeth and jaws and their specialisms
7. know that chewing, tongue action and saliva all help to break up food physically
8. know that saliva wets food and has the enzyme amylase to start the chemical
digestion of starch to maltose
9. identify that peristalsis is the controlled pushing of food through the gut
10. identify that stomach acid kills germs and provides a low pH for the enzyme
pepsin in gastric juice which helps to break down proteins chemically
11. identify that muscular churning of the stomach helps with the physical breakdown
12. identify that in the duodenum, further chemical digestion starts
13. know that pancreatic juice, from the pancreas, is secreted into the duodenum and
that it contains protease, carbohydrates and lipase enzymes and sodium carbonate
to help neutralise stomach acid
14. know that bile from the liver is stored in the gall bladder
15. know that bile is use in the duodenum to emulsify fats and help neutralise acid
16. know that the ileum has a multi-folded surface of villi which have microvilli .
This increases the surface area for absorption and there is an excellent blood
supply for transport
17. know that the large intestine reabsorbs water from waste into the blood
18. know that the rectum stores faeces for egestion via the anus
19. know the role of an enzyme
20. explain the structure of an active site in terms of its specificity
21. explain the term denaturing in terms of the effect of temperature and pH on the
active site.