topic 5 photosynthetic pigments

what do photosynthetic pigments do?

absorb light energy and convert it into chemical energy

what do chlorophylls do?

they play a direct role in the first stage of photosynthesis

what do carotenoids do?

absorb light energy, which is passed on to chlorophyll

what is an accessory pigment?

light-absorbing molecules that pass on the energy they absorb to chlorophyll molecules at the start of photosynthesis

what is the head of a chlorophyll molecule like?

hydrophilic ring structure with a magnesium atom in its centre

what is the tail of a chlorophyll molecule like?

long hydrophobic hydrocarbon tail

how is a chlorophyll molecule attached to a chloroplast?

by their tails, whilst the heads lie flat on the membrane surface to absorb the maximum amount of light

absorption spectra

graphs showing the amount of light at each wavelength

action spectra

graphs showing the rate of photosynthesis at different wavelengths

what does action and absorption spectra having similar patterns show?

supports model of light being trapped by these pigments and used in photosynthesis

why do plants have more than one pigment?

a combination of two or more pigments means that a greater range of wavelengths can be absorbed efficiently