P11 - The Hill Reaction

Question 1

Describe The Process Of Investigating The Hill Reaction
(6 Points)

Answer 1

~ Use a pestle and mortar, to grind up leafs, with an isolation solution.

~ Filter liquid into a clean beaker, then transfer filtered into a centrifuge tube, and place in the centrifuge for 10 mins.

~ Re-suspend pellets in fresh isolation solution, and store in ice for the rest of the experiment.

~ Place a test tube containing chloroplast extract, at a set distance from a lamp and add DCPIP, then mix the solutions.

~ Take a sample of the mixture and place in a clean curvette and place into a colorimeter, record absorbance.

~ Repeat

Question 2

Why Is A Isolation Solution Used?

Answer 2

Prevent cell damage, due to osmosis or extreme pH.

Question 3

What Does The Centrifuge Do?

Answer 3

Results in a pellet of chloroplasts, forming at the bottom of the tube.

Question 4

What Does Storing The Solution In Ice Do?

Answer 4

Slows down the activity of the chloroplasts.

Question 5

Describe The Results Of The Hill Reaction

Answer 5

~ Absorbance reading should decrease, as the DCPIP gets reduced.

~ The solution changes from blue to colourless, reducing the amount of light absorbed.