BioInteractive Photosynthetic Pigments and Light Absorption 2

Question 1

What is the difference between the absorption spectrum and the action spectrum of a pigment?

Accepted Answer

Absorption spectrum shows light absorbed by the pigment; action spectrum shows which wavelengths drive photosynthesis

Answer

The absorption spectrum measures which wavelengths a pigment absorbs, while the action spectrum measures the rate of photosynthesis at each wavelength.

Question 2

Which pigment absorbs light primarily in the blue-violet range and is found in antenna complexes?

Accepted Answer

Chlorophyll b

Answer

Chlorophyll b absorbs light mainly in the blue-violet range (~453 nm) and transfers energy to chlorophyll a reaction centers.

Question 3

What is the light-harvesting complex (antenna complex) in a photosystem?

Accepted Answer

A cluster of pigment molecules that absorbs light and funnels energy to the reaction center

Answer

The antenna complex consists of many chlorophyll and accessory pigment molecules that capture photons and transfer the energy via resonance to the reaction center.

Question 4

How does increasing light intensity affect the rate of photosynthesis up to a point?

Accepted Answer

Rate increases until a light saturation point is reached

Answer

As light intensity increases, photosynthesis rates rise until the light saturation point, where other factors (CO2, temperature) become limiting.

Question 5

What is resonance energy transfer in the context of photosynthetic pigments?

Accepted Answer

Energy passes from one pigment molecule to adjacent ones until it reaches the reaction center

Answer

Resonance energy transfer (also called Förster resonance) moves excitation energy between closely packed pigment molecules without electron transfer until the reaction center is reached.

BioInteractive - Photosynthesis BioInteractive Test Practice Test

BioInteractive - Photosynthesis BioInteractive Test Practice Test

BioInteractive Photosynthetic Pigments and Light Absorption 2