Photosynthesis Review

Pigments & Light Absorption

100

This primary pigment absorbs blue and red light, reflecting green.

Chlorophyll a or b

200

These accessory pigments absorb blue-green light, and are more visible during the fall months

carotenoids

300

This graph shows how different pigments absorb various wavelengths of light.

Absorption spectrum

400

A plant with phycoerythrin would look this colour... 

Violet - Blue

500

A plant is seen to have white leaves.  What colours of light does it absorb?  Is it healthy?  Explain.

The plant reflects all colour, and doesn't absorb any light.  It is not healthy, and is usually a sign that the plant is diseased.  It will probably die.

Photosystems & Electron Flow

100

This photosystem splits water and releases oxygen.

Photosystem II (PSII)

200

The molecule that carries electrons from PSII to PSI in the ETC.

Cytochrome B6

300

The final electron acceptor in the light-dependent reactions.

NADP⁺ (forms NADPH)

400

 If PSII is blocked, these three products would stop being made.

O₂ and ATP

500

"Photosystem I reduces water and uses the electrons to pump H+ ions into the stroma from the thylakoid lumen.  Then, photosystem II re-energerizes the electron, helping to reduce NADP+ to NADPH". 

Find three incorrect parts in this statement

Photosystem II (not I) oxidizes (not reduces) water, and pumps H+ ions from the stroma to the thylakoid (not the thylakoid to the stroma)

Light-Dependent Reactions

100

This enzyme produces ATP using a proton gradient.

ATP synthase

200

The source of replacement electrons for PSII.

Water (photolysis)

300

The process by which H⁺ ions drive ATP synthesis.

chemiosmosis

400

If the plant is stressed, this type of photophosphorylation would take place

cyclic photophosphorylation

500

The Light-Dependent reactions use and produce which parts of the general summary equation for photosynthesis: CO₂ + H₂O --> C₆H₁₂O₆ + O₂

H₂O and O₂

Calvin Cycle (Light-Independent Reactions)

100

The enzyme that fixes CO₂ to RuBP.

Rubisco

200

The 3-carbon molecule produced after CO₂ fixation.

PGA

300

How many CO₂ molecules are needed to make one glucose?

6

400

If the Light-Dependent reactions stopped working, this product wouldn't get made in the Calvin cycle

G3P

500

The Calvin cycle most resembles this phase of cellular respiration

the Kreb's cycle

Experimental & Critical Thinking

100

A plant in total darkness would fail to produce this gas.

Oxygen

200

Why is green light inefficient for green plants to do photosynthesis?

Chlorophyll reflects green light

300

If the ETC is blocked, what accumulates in the thylakoid?

H+ ions

400

Why would no water stop the Calvin Cycle?

No NADPH would be generated for the reduction phase of the calvin cycle

500

A mutant plant has working PSII but broken PSI. What can it make? What can't it make?

Can make ATP, can't make NADPH or O₂