Required Practical 8 -chloroplasts

Question 1

Aim of chloroplasts rp

Answer 1

To investigate the effect of the addition of ammonium hydroxide (or a variable) has on the rate of dehydrogenase enzyme on chloroplasts

Question 2

Background of enzymes, photosynthesis and the rp

Answer 2

Photoionsiation of chlorophyll and photolysis of water both occur in the light dependant reaction of photosynthesis and release electrons
The dehydrogenase enzyme naturally occurs in chloroplasts and catalyses reaction involved in the NADP accepting these electrons

DCPIP is a redox indicator so changes colour depending on whether the chemical is oxidised or reduced
DCPIP is blue when oxidised and colourless when reduced. It can pick up electrons from the LDR instead of NADP
Ammonium hydroxide is an alkaline so could denatured the dehydrogenase enzyme. Ammonium hydroxide can also accept electrons,so could pick up electrons instead of DCPIP and NADP

Question 3

Hypothesis of chloroplast rp

Answer 3

The rate of reaction will decrease with the addition of ammonium hydroxide