Digestive System-Food Tests

Question 1

Describe how the organs of the digestive system
work together to digest and absorb food.

Answer 1

The mouth begins the digestion of carbohydrates.
The stomach begins the digestion of proteins; small molecules such as alcohol is absorbed.
The small intestine - Duodenum continues the digestion of carbohydrates and protein; begins the digestion of lipids
The small intestine - Ileum completes the digestion of carbohydrates and proteins into single sugars and amino acids; absorption of single sugars, amino acids and fatty acids and glycerol

Question 2

Describe how to test for sugars

Answer 2

Benedict’s test is used to test for sugars, After heating, it may go through stages - green, yellow, orange, red or brown - depending on how much glucose is present

Question 3

Describe how to test for starch

Answer 3

Iodine solution is used to test for starch. Foods containing starch will turn a blue-black colour.

Question 4

Describe how to test for protein

Answer 4

The biuret test is used to detect proteins. A purple colour indicates that protein is present OR a purple ring in between the layers

Question 5

Describe how to test for lipids

Answer 5

The Sudan III test is one test used to test for lipids. A red stained layer will form on the surface of the water if lipids are present,