year 9 biology food tests

1. using a measuring cylinder, measure 2ml of water into a test tube. 

2. add a small spatula of starch and shake 

3. add 4 drops of iodine.

4. record the colour change of the iodine. 

1. measure 2ml of water into a test tube. 

2. add a small spatula of protien powder and shake. 

3. add 2ml of bluret solution 

4. record the colour change of the bluret solution.

1. place 3 drops of oil onto test tube. 

2. add 5ml of ethanol and shake the test tube to dissolve the oil. 

3. leave the tube to settle for 2 minutes. 

4. pour the top two thirds of liquid into a clean test tube.

5. add a small amount of water and record the colour change. 

1. measure 3ml of water into a boiling tube. 

2. add a spatula of glucose and shake. 

3. add 3ml of benedicts solution.

4. half fill a beaker with water and heat it on a tripod and gauze until the water is boiling.

5. turn off the bunsen. 

6. stand the boiling tube containing glucose and benedicts solution in water and record what happens. 

reagent name - iodine

colour of the reagent before the test - orange/ brown

colour ofreagent after the test - black / purple

heathing involved - no

reagent name - bluret 

colour of the reagent before the test - blue

colour ofreagent after the test - light purple

heathing involved - no

reagent name - ethanol 

colour of the reagent before the test - colourless

colour ofreagent after the test - cloudy white 

heathing involved - no

reagent name - benedict 

colour of the reagent before the test - blue

colour ofreagent after the test - orange

heathing involved - bunsen burner

reagent name - benedict 

colour of the reagent before the test - blue

colour ofreagent after the test - orange

heathing involved - bunsen burner

reagent name - benedict 

colour of the reagent before the test - blue

colour ofreagent after the test - orange

heathing involved - bunsen burner