BioInteractive Photosynthetic Pigments and Light Absorption 3

Question 1

What happens to a chlorophyll molecule after it absorbs a photon?

Accepted Answer

An electron is excited to a higher energy level

Answer

It splits water immediately

Answer

It fixes CO2

Answer

It produces glucose directly

Question 2

Which pigment is most directly involved in the initial photochemical reaction at the reaction center?

Accepted Answer

Chlorophyll a

Answer

Chlorophyll b

Answer

Beta-carotene

Answer

Xanthophyll

Question 3

What is photoprotection and which pigments are primarily responsible for it?

Accepted Answer

Protection of the photosynthetic machinery from excess light damage, primarily by carotenoids

Answer

Absorption of extra CO2 by chlorophyll

Answer

Production of antioxidants by anthocyanins

Answer

Reflection of UV light by the leaf surface

Question 4

What color of light is LEAST effective at driving photosynthesis in most plants?

Accepted Answer

Green

Answer

Red

Answer

Blue

Answer

Violet

Question 5

What is the significance of the 'red drop' observed in photosynthesis action spectra?

Accepted Answer

Photosynthetic efficiency drops sharply at wavelengths above 680 nm, suggesting two photosystems work together

Answer

Chlorophyll absorbs more red light than blue

Answer

Red light heats the leaf and slows photosynthesis

Answer

Carotenoids absorb all light above 680 nm

Question 6

What is the Emerson enhancement effect?

Accepted Answer

Simultaneous illumination with both far-red and shorter-wavelength red light gives more photosynthesis than the sum of each alone

Answer

Adding more CO2 enhances the effect of light

Answer

Temperature increases enhance light absorption

Answer

Increasing pigment concentration boosts absorption linearly