Photosynthesis Test

ATP, NADPH, Oxygen

What is given off in light reactions?

Light Reactions: Light, water, ADP, NADP+/ ATP, NADPH, O2 Calvin Cycle: CO2, ATP, NADPH/ G3P, ADP, NADPH

What are the major inputs and outputs of the two stages of Photosynthesis?

Carbon Fixation, Reduction, release of G3P, and Regeneration of RuBP

What are the steps of the Calvin Cycle?

Plants break down sugar for energy in cellular respiration, Excess stored as starch.

What do plants do with the sugar they produce in photosynthesis?

Release of Oxygen

What does not occur during the Calvin Cycle?

Splitting water

After light strikes chlorophyll molecules, electrons are lost but ultimately replaced by __ __.

6

Assuming that one CO2 is fixed per turn, how many turns of the Calvin Cycle are required to produce one molecule of glucose?

Electron transport chain pumps H+ into the thylakoid space, concentration gradient drives H+ back through ATP synthase.

Photophosphorylation

Calvin Cycle depends on products of light reactions

The reactions of the Calvin Cycle do not depend on light but they usually occur at night. Why

6 CO2, 18 ATP, and 12 NADPH Glucose is valuable as an energy source because of how much potential energy is stored in its electrons. The moe energy a molecule stores, the more reducing power is required to reproduce that molecule.

To synthesize, one glucose molecule, the Calvin Cycle uses __ CO2, __ ATP, and __ NADPH. Explain why the high number of ATP and NADPH is consistent with the value of glucose.

G3P is constructed with the use of carbon in CO2, and electrons from NADPH, energy from ATP and is used to build glucose, etc.

What goes on in the Calvin Cycle?

Electrons that move from photosystem II to photosystem I provide energy to make ATP and then reduce NADP+ to NADPH. Photosystem II regains electrons as water is split and oxygen is released.

What goes on in the light reactions?

Photophosphorylation

What is chemiosmosis called in photosynthesis?

ATP and NADPH

What is produced by reactions in the thylakoids and consumed by reactions in stroma?

The Calvin Cycle which uses NADPH and ATP occurs in the stroma.

What is the benefit of ATP and NADPH being produced on the so close to the thylakoid?

Energy from 6 ATP molecules is consumed and 6 NADPH molecules are oxidized. The 6 3-PGA are reduced to 6 molecules of G3P.

What occurs during reduction?

An enzyme called Rubisco, combines carbon dioxide with ribulose diphosphate (RuBp). The product is unstable (Phosphoglyceric acid). For 3 carbon dioxide, 6 3- GPA result.

What occurs in carbon fixation?

5 G3P remain in the cycle, one molecule left the cycle however. G3p is used to make glucose, etc.

What occurs in the 3rd step of the Calvin Cycle?

3 ATP molecules' energy is used to rearrange the 5 G3P into 3 RuBp from the beginning of the cycle.

What occurs in the fourth step of the Calvin Cycle?

Split Water, NADP+, NADPH, Calvin Cycle

Where do electrons flow throughout photosynthesis?

Photosynthesis is the source of food for almost all organisms and the oxygen they need. Energy storage is photosynthesis, energy harvest is cellular respiration.

Explain the importance of photosynthesis.

In respiration, electrons come from oxidation of organic molecules. In photosynthesis, light energy drives electrons from water to the top of the electron transport chain. In photosynthesis, the final electron acceptor is NADP+, unlike the final electron acceptor in respiration, oxygen. Light reactions provide chemical energy (ATP) and reducing power (NADPH).

How do photophosphorylation and chemiosmosis of respiration compare?

Water, carbon dioxide

In photosynthesis, __ is oxidized and __ is reduced.