Photosynthesis Required Practical

Question 1

Photosynthesis Required practical

Answer 1

1. Set up a test tube rack containing a boiling tube at a distance of 10 cm away from the light source
2. Fill the boiling tube with the sodium hydrogen carbonate solution
3. Put the pond weed into the boiling tube with the cut end at the top and push down with glass rod so fully submerged
4. Leave the boiling tube for 5 minutes
5. Start the stopwatch and count the number of bubbles produced in a minute
6. Record the results in a table
7. Repeat the test 2 more times and using your data calculate the mean number of bubbles per minute
8. Repeat steps 1-7 with the test tube rack and boiling tube at distances of 20cm, 30cm, and 40cm from the light source

Question 2

Food Tests Practical

Answer 2

1. Use a pestle and mortar to grind up a sample of food
2. Transfer the ground up food into a small beaker and add distilled water
3. Stir the mixture so some of the food dissolves in the water
4. Filter using a funnel and filter paper and collect in a conical flask
5. Half fill a test tube with this solution and add 10 drops of benedicts solution
6. Put hot water from a kettle into a beaker and place test tube in beaker for 5 minutes
7. If glucose is present - the solution will turn green, yellow or brick red
8. Take 5ml of the solution from conical flask and place in a clean test tube
9. Add a few drops of iodine solution - if starch is present, you should see a black or blue-black colour appear
10. Record your results in a table

Question 3

Enzymes Required Practical

Answer 3

1. Place one drop of iodine solution into each depression on the spotting tile
2. Place labelled test tubes containing buffered pH solutions, amylase solution and starch solution in a water bath
3. Allow the solutions to reach 25 degrees
4. Add 2cm of one of the buffered solution to a test tube
5. Add 2cm of amylase to the test tube using a syringe
6. Immediately start the stopwatch and mix using a glass rod
7. After 30 seconds, take one drop of the mixture and place it on one of the depressions with the iodine which should turn blue-black
8. Rinse the rod and repeat every 30 seconds until the iodine solution and the mixture remain orange
9. Repeat the procedure with other solutions of other pH
10. Record your results in a table