Describe how Carbon Dioxide is assimilated in the Calvin cycle.

CO2 from the atmosphere diffuses into the leaf through the stomata and then into the stroma within the chloroplasts of mesophyll cells.  In the stroma the enzyme Ribusco catalyes the combining of CO2 with ribulose bisphosphate to form an intermediate which breaks down into two glycerate -3-phosphate molecules. The hydrolysis of ATP ( produced in the light dependent reaction) releases energy which is used to reduce glycerate -3 - phoshpate into triose phosphate. The reductant NADPH is oxidised to regenreate NAPD+ which is again able to accept hydrogen from the photolysis of water. Some triose phosphate molecules are used to produce useful organic substances like glucose while most are used to regenerate ribulose bisphosphate.

VA

Related Biology A Level answers

All answers ▸

Why is the actual yield of ATP during aerobic respiration lower than the theoretical yield of 38 ATP molecules?


Type 1 Diabetes is an autoimmune disease affecting the bodies ability to produce insulin. Describe how blood glucose is controlled in the body to a stable level, and how this would be affected in someone with type 1 diabetes.


Describe the role of DNA polymerase in DNA replication.


Explain how certain molecules or ions increase the activity of enzymes.