Lecture 16 Flashcards
1
Q
What are the three phases of the Calvin cycle?
A
-carbon fixation
-reduction
-regeneration
^ in that order
2
Q
Describe carbon fixation?
A
- each CO2 attached to ribulose bisphosphate (RuBP) by the enzyme RUBISCO
- product unstable
- splits into 3 carbon sugars
3
Q
Describe reduction
A
- 3 carbon sugars are phosphorylated by ATP
- reduced by NADPH
- lose phosphate group
- G3P molecule produced and leaves
4
Q
Describe regeneration of RuBP
A
Carbon skeletons of G3P rearranged to form RUBP, uses 3 ATP
5
Q
What is the cyclical electron flow?
A
Alternate mode of photosynthesis that only involves first electron chain carriers and psi
6
Q
What is a stroma?
A
Pores in plants to bring in CO2 and release water
7
Q
What are bundle sheath cells?
A
Layer of cells between vascular tissue and stroma
8
Q
Describe the daily acid cycle in CAM plants
A
- Decrease in PH over night- increase in crassulacean acid production
- build up of starch I.e Calvin cycle through the day
9
Q
Why does rubisco bind with O 2 as well as CO2?
A
Rubisco first involved at a time when the atmosphere had far less O2 and more CO2
