B2 - Food Tests

Question 1

How to get food sample

Answer 1

Break up pieces of food using a pestle and mortar
Transfer to the beaker and add distilled water and stir to dissolve some of the food
Filter to get rid of of solid bits of food

Question 2

Test for Sugars

Answer 2

5cm^3 of food sample in a test tube
Water bath to 75 degrees Celsius
Add 10 drops of BENEDICTS SOLUTION to a test tube and place in the water bath for 5 minutes
Blue — green, yellow, brick red (depending on how much sugar is in food)

Question 3

Test for Starch

Answer 3

Add a few drops of IODINE SOLUTION and gently shake
If it contains starch it will turn from BROWN-ORANGE to BLUE/BLACK

Question 4

Test for Protein

Answer 4

Biuret Solution
BLUE to LILAC

Question 5

Test for Lipids

Answer 5

5cm^3 of food sample into a test tube
3 drops of Sudan III STAIN SOLUTION
If there are lipids, the mixture will separate with the top layer being bright red

Question 6

What do carbohydrases (amylase) break down?

Answer 6

Starch into Maltose (

Question 7

Where is amylase made?

Answer 7

Salivary Gland
Pancreas
Small intesting

Question 8

What does protease break down?

Answer 8

Proteins into Amino acids

Question 9

Where is protease made?

Answer 9

Stomach (pepsin)
Pancreas
Small intestine

Question 10

What does lipase break down

Answer 10

Lipids into The glycerol and fatty acids

Question 11

Where is lipase made

Answer 11

Pancreas
Small intestine

Question 12

What does bile do

Answer 12

Alkaline - so it neutralises acid to make conditions more alkaline as the enzymes in small intestine work best in alkaline conditions

Emulsifies fats to increase surface area for lipase to work on

Question 13

Where is bile produced and where is it stores

Answer 13

Produced in liver
Stored in gall bladder