Question

Describe the similarities and/or differences between the following (at least 4 similarities or differences for each):

1. production of ATP in oxidative phosphorylation and production of ATP in the membrane associated (light) reactions
2. photosystem I and photosystem II
3. citric acid cycle (Kreb cycle) and Calvin cycle

Answer 1

Production of ATP in oxidative phosphorylation and membrane assosciated light reaction

In both reactions electrons are transferrred through a series of membrane protiens and pump H+ ptotons to one side of the membrane and make ATP eith the help of ATP synthase.

Differences

Production of ATP in Photophosphorylation	Production of ATP in Oxidative phosphorylation
1. Energy stored in ATP is obtained from sun.	Energy stored in ATP is obtained by oxidation of organic compounds
2. ATP used to fix CO2 and carbohydrate in dark reaction	ATP produced released to cytoplasm and used from metabolic reaction
3. Proton pumping into the thylakoid space of chloroplasts	Proton pumping to outside matrix of mitochondria
4. 18 ATP and 12 NADPH are required	30-36ATP formed in one reaction
5. .ATP production occurs during photosynthesis	Occurs during cellular respiration

Photosystem I and II

Both are involved in the photophosphorylation reaction.

Photosystem I	Photosystem II
1. Absorbs longer wavelength – 700nm	Absorbs shorter wavelength – 680 nm
2. Seen in the outer surface of thylakoid	Seen in the inner surface of thylakoid
3. Both cyclic and non cyclic photophosphorylation	Cyclic photophosphorylation
4. Obtain electrons from photosystem II and use light energy to convert NADP= to NADPH2+	Obtain electrons by the conversion of water to H+ and Oxygen. Photolysis occurs.

Calvin cycla and Krebs cycle

Both are cyclic process. Calvin cycle requires short term of light. Calvin cycle occurs in chloroplasts and Kreb"s cycle in mitochondria

Calvin cycle	Kreb’s cycle
1. Occurs in plants	Occurs in aerobic organisms including plants
2. Anaerobic process	Oxygen essential for Kreb’s cycle
3. Produce glucose using energy	Oxidise glucose and release energy
4. ATP and CO2 used in the cycle	ATP and CO2 produced in the cycle