Review Questions for Photosynthesis

Match the processes/sets of reactions with the descriptions. Each question

can have more than one answer.1. Requires CO22. Requires water3. Glucose is a product4. Oxygen is a product5. Occurs in the stroma6. Occurs in the thylakoid membrane7. NADP+ is required to go in8. NADPH is required to go in9. Carbon dioxide is reduced10. NADPH is oxidized to form NADP+11. Makes ATP 12. NADP+ is the final electron acceptor

A. Light reactionsB. Dark reactionsC. Calvin cycleD. Electron

Transport ChainE. Chemiosmosis

B, CA, D

B, CA

B, CA, D, E

A, D B, C

B, CB, C

A, EA, D

Match the processes/sets of reactions with the descriptions. Each question

can have more than one answer.1. Requires enzymes located in the

stroma.2. Makes use of ATP synthase.3. Uses cytochromes4. NADP+ is reduced5. Creates a hydrogen ion gradient6. Includes cyclic & noncyclic

photophosphorylation7. Driven by the energy of a proton

gradient8. Is part of cellular respiration9. Provides energy for the dark reactions

B, CA, EA, D

A, DD

A

D, EE

A. Light reactionsB. Dark reactionsC. Calvin cycleD. Electron

Transport ChainE. Chemiosmosis

A, D, E

What happens in A?

A

BC D (the line)

E

• Glycolysis and fermentation• Anaerobic processes

• Formation of 2 ATP by substrate-level phosphorylation

What happens in B?

A

BC D (the line)

E

• Dark/Calvin cycle reactions occur here so all the enzymes for these reactions are located here• CO2 is fixed into an organic molecule

• CO2 is reduced by NADPH to produce PGAL/G3P• NADPH is oxidized to form NADP+• ATP is used up & ADP is produced

• RuBP is regenerated

STROMA

What happens in C?

A

BC D (the line)

E

• Hydrogen ions (protons) are pumped (actively transported) here by the

electron transport chain• pH is lowered because of added H+ (pH=5

when light is shining on chloroplast)

Thylakoid space

What happens in D?

A

BC D (the line)

E

• Light reactions – cyclic & noncyclic photophosphorylation

• Water is split using light energy• the electron transport chain located here actively

transports hydrogen ions (protons) into the thylakoid space

• Oxidation-reduction reactions• ATP & NADPH synthesis on the outside (stroma

side) surface • Chemiosmosis of ATP Thylakoid

membrane

What does this represent? Identify A through F.

A

B

C

D

E

F

ChloroplastA – water (H2O)B – Oxygen gas (O2)C – Carbon dioxide (CO2)D – Glucose (C6H12O6)E – ATP and NADPHF – ADP and NADP+

Put the descriptions where they belong Non-cyclic

photophosphorylation Cyclic photophosphorylation

Occurs in the thylakoid membrane Produces ATP

Produces NADPHMore primitive/less evolved

Uses photosystem I (P700)Uses photosystem II (P680)Splits water

Releases oxygen gas (O2)

Uses the electron transport chain

Electrons return to P700 (PS I)

Electrons are excited by light

Photolysis

Put the following in order of the passage of energy during

photosynthesis.• ATP• Light• Electron Transport

Chain• Glucose• Chlorophyll• Hydrogen ion (H+)/

proton gradient

1. Light2. Chlorophyll3. Electron Transport

Chain4. Hydrogen ion (H+)/

proton gradient5. ATP6. Glucose

True or False: If the statement is false, replace the underlined word/phrase to

make the statement read true.1. Water is a reactant for the light reactions.2. G3P is a product of the Calvin cycle.3. Carbon dioxide is oxidized during the process of

photosynthesis.4. Water is oxidized during the process of

photosynthesis.5. The enzymes that carry out the Calvin cycle are only

active in the dark.6. The reactant for the reduction phase of the Calvin

cycle is CO2.

TRUE

TRUE

FALSE – reduced (since it picks up H atoms from NADPH)

TRUE – it loses electrons/hydrogen

FALSE -- active in light or dark – as long as there is ATP and NADPH around.

FALSE – carbon fixation.

True or False: If the statement is false, replace the underlined word/phrase to

make the statement read true.1. The carbon fixation stage of the Calvin cycle begins when

CO2 joins with oxaloacetate, a 4-carbon compound.

2. Oxygen is a product of the Calvin cycle.3. The final electron acceptor in the electron transport chain

within a chloroplast is NAD +.4. The final electron acceptor in the electron transport chain

within a mitochondrion is oxygen.5. The high energy molecules that provide the energy to

reduce CO2 are ADP and NADP+

6. The product for the regeneration phase of the Calvin cycle is CO2.

FALSE – RuBP, a 5-carbon.

FALSE – noncyclic photophosphorylation/light reactions.

FALSE – NADP+.

TRUE

FALSE – ATP & NADPH

FALSE – RUBP

Which of the following does not belong? Write one or two sentences using the other words that

explain how all the other words are related.1. Photolysis, Calvin cycle, photophosphorylation,

thylakoid membrane, chemiosmosis

2. Carbon fixation, reduction, regeneration, RuBP, oxaloacetate, PGAL, rubisco

3. G3P, NADPH, ATP, 3PGA, RuBP

Within the thylakoid membrane in a chloroplast, noncyclic photophosphorylation occurs where water is split using light energy in a process called photolysis. The electrons from water are energized and passed down an electron transport chain which sets up a H+ ion (proton) gradient whose energy is used to make ATP through chemiosmosis.

During the Calvin cycle, carbon fixation (catalyzed by the enzyme rubisco) is followed by reduction and regeneration to re-form RUBP which was a reactant in carbon fixation in the first place. PGAL or G3P is the 3-carbon product of the Calvin cycle/dark reactions.

During the reduction phase of the Calvin cycle, 3PGA are reduced and phosphorylated by NADPH and ATP and G3P is produced.