what is the function of pigment molecules in photosynthesis?

Answer 1

Chlorophylls are the primary photosynthetic pigment class They reflect green and absorb blue and red wavelengths. Chlorophyll alpha does the primary electron capture to drive the process of generating carbohydrates for long term storage of energy.
Accessory pigments can include chlorophyll b, xanthophylls, and carotenoids (such as beta-carotene). They absorb energy from spectra that chlorophyll a does not absorb and pass it to chlorophyll a.
Chlorophyll a with accessory pigment Chlorophyll b are in light harvesting complexes in plants. Chlorophyll b differs from alpha only by its 7-formyl group. Its main function is to collect energy but a secondary function is to regulate the light harvesting antenna size.
Chlorophyll c1, & Chlorophyll c2 are present in brown algae, diatoms, and flagellates.
Chlorophyll d is in Cyanobacteria Acaryochloris marina with a far-red, 740nm absorption, type of photosynthesis paired with chlorophyll a.


Carotenoids reflect yellow, orange, or red and absorb blue light. There are over 600 known carotenoids and they pass their energy to the chlorophyll so they are the second photosynthetic pigment. http://en.wikipedia.org/wiki/Carotenoid
Carotenoids collect light in wavelengths chlorophyll can’t then transfer it to chlorophyll. They also absorb excess light energy and dissipate it in order to avoid damage in what is termed the Xanthophyll Cycle. Xanthophylls are a common but sub class of the carotenoid group.

Anthocyanins, are also an ancillary pigment class that reflect red, blue, purple, or magenta colors. Recent literature reports some 550 but these are not involved in photosynthesis. They give color to flowers & fruit and are there for protection from UV or oxidative damage.

The third photosynthetic pigment class, Phycobilins are not found in leaves. They occur in Cyanobacteria and Rhodophyta's photosynthesis pathway.

Accessory pigments fill in the 'green gap' in chlorophyll a. Light absorption under water is best in the long penetrating red wavelengths where chlorophyll a mostly absorbs. The accessory pigments arose later to capture the high energy blue light and to fill the green gap.

Why visible spectra ?
400< Chlorophyll's absorption < 700 nm.
Below 400nm the increasing energy of the photons increase the risk of photochemical damage. Beyond 700 nm the energy levels are insufficient to effectively drive photochemistry (except in cyanobactria with chlorophyll d p740).

Answer 2

Pigment Molecules

Answer 3

WELL to be exact cuvette 2: to observe the role of photosynthesis with chromatin cuvette 3: to observe the role of photosynthesis with UV rays cuvette 4: to observe the stability of the chloroplasts cuvette 5: to observe the reaction of the H2O synthesis

Answer 4

They absorb light from the sun