Chapter 11: Photosynthesis Flashcards
during the light-independent reaction of photosynthesis, carbon dioxide is converted into organic substances. Describe how. [6 marks]
- carbon dioxide combines with ribulose bisphophate/ RuBP
- produces two glycerate 3 phosphate
- GP reduced to triose phosphate
- using reduced NADP
- using energy from ATP
- triose phosphate converted to glucose
Crops use light energy to produce photosynthetic products. Describe how crop plants use light energy during the light-dependent reaction. [5 marks]
- excites electrons / electrons removed from chlorophyll
- electrons move along carriers/electron transfer chain releasing energy
- energy used to join ADP + Pi to form ATP
- photolysis of water produces protons, electrons and oxygen
- NADP reduced by electrons / electrons and protons / hydrogen
During photosynthesis, oil-palm trees convert carbon dioxide into organic substances. Describe how. [6 marks]
- carbon dioxide combines with ribulose bisphosphate
- produces two molecules of glycerate 3 phosphate
- reduced to triose phosphate
- using reduced NADP
- using energy from ATP
- triose phosphate converted to other organic substances
- in light independent reaction
describe the light-independent reaction of photosynthesis. [6 marks]
- carbon dioxide combines with ribulose bisphosphate
- produces two glycerate 3 phosphate using rubisco
- GP reduced to triose phosphate
- using reduced NADP
- using energy from ATP
- triose phosphate converted to glucose
Energy enters most ecosystems through the light-dependent reaction of photosynthesis. Describe what happens during the light-dependent reaction. [5 marks]
- chlorophyll absorbs light energy
- excites electrons / electrons removed
- electrons move along carriers / electron transport chain releasing energy
- energy used to join ADP + Pi to form ATP
- Photolysis of water produces protons, electrons and oxygen
- NADP reduced by electrons / electrons and protons / hydrogen
In the light-dependent reaction of photosynthesis, light energy generates ATP. Describe how. [5 marks]
- light energy excites / raises energy level of electrons in chlorophyll
- electrons pass down electron transfer chain
- electrons reduce carriers / passage involves redox reactions
- electron transfer chain / role of chain associated with chloroplast membranes
- energy released / carriers at decreasing energy levels
- ATP generated from ADP and phosphate
The concentrations of carbon dioxide in the air at different heights above ground in a forest changes over a period of 24 hours. Use your knowledge of photosynthesis to describe these changes and explain why they occur. [5 marks]
- high concentration of carbon dioxide linked with night
- no photosynthesis in dark
- plants respire
- In light net uptake of carbon dioxide by plants / plants use more carbon dioxide than they produce / rate of photosynthesis greater than rate of respiration
- decrease in carbon dioxide concentration with height
- at ground level fewer leaves / less photosynthesizing tissue / more animals / less light
In the light-independent reaction of photosynthesis, the carbon in carbon dioxide becomes carbon in triose phosphate. Describe how. [5 marks]
- carbon dioxide combines with ribulose bisphosphate
- to produce two molecules of glycerate 3 phosphate
- reduced to triose phosphate
- requires reduced NADP
- energy from ATP