Chemiosmosis in chloroplasts is possible because of:

1.	establishment of a proton gradient across the thylakoid membrane.
2.	diffusion of electrons through the ATP synthase.
3.	osmosis of water from thylakoid to stroma.
4.	presence of large amount of oxygen in the stroma.

The ATP synthase complexes in a plant cell are located:

In chloroplasts, protons are actively pumped from
1. the intermembrane space to the matrix.
2. the matrix to the stroma.
3. the stroma to the thylakoid space.
4. the thylakoid space to the intermembrane space.

The following diagram shows the ${\mathrm{C}}_4$ photosynthetic carbon cycle. A and B can respectively be:
   
1. Pyruvate; malate or aspartate
2. Phoshoglycerate; fumarate or aspartate
3. Phosphoenol pyruvate; malate or aspartate
4. Phosphoenol pyruvate; fumarate or aspartate

The relationship between photosynthesis and respiration can be best described as:

Probably the strongest biological oxidizing agent is P680+ because:

The primary function of the Calvin cycle is to:
1. use ATP to release carbon dioxide
2. use NADPH to release carbon dioxide
3. split water and release oxygen
4. fix inorganic carbon to simple sugars

Which of the following must occur in the biochemical pathway of Calvin cycle?
1. addition of a pair of electrons from NADPH
2. inactivation of RuBP carboxylase enzyme
3. regeneration of ATP from ADP
4. regeneration of RuBP

Given below is the schematic diagram of Calvin cycle taking place in a certain plant. ATP used by this plant is radioactively labeled. One turn of the cycle is allowed to happen. Radioactivity would be seen in all except:

1. A
2. B
3. C and D
4. E

For the synthesis of glucose, the source of hydrogen atoms is: