All photosynthesis in green plants and algae occurs in chloroplasts.

This process is called photosynthesis. Temperature, carbon dioxide concentration and light intensity are factors that can limit the rate of photosynthesis.

Some of these thylakoids are present in the stacked form and are referred to as grana.

Plants absorb water through their roots, and carbon dioxide through their leaves. Some glucose is used for respiration, while some is converted into insoluble for storage. The stored starch can later be turned back into glucose and used in respiration. Oxygen is released as a by-product of photosynthesis.


This all happens in the grana of chloroplasts.

The different sidegroups in the 2 chlorophylls 'tune' the absorption spectrum to slightly different wavelengths, so that light that is not significantly absorbed by chlorophyll , at, say, 460nm, will instead be captured by chlorophyll , which absorbs strongly at that wavelength. Thus these two kinds of chlorophyll complement each other in absorbing sunlight. Plants can obtain all their energy requirements from the blue and red parts of the spectrum, however, there is still a large spectral region, between 500-600nm, where very little light is absorbed. This light is in the region of the spectrum, and since it is reflected, this is the reason plants appear green. Chlorophyll absorbs so strongly that it can mask other less intense colours. Some of these more delicate colours (from molecules such as carotene and quercetin) are revealed when the chlorophyll molecule decays in the Autumn, and the woodlands turn red, orange, and golden brown. Chlorophyll can also be damaged when vegetation is cooked, since the central Mg atom is replaced by hydrogen ions. This affects the energy levels within the molecule, causing its absorbance spectrum to alter. Thus cooked leaves change colour - often becoming a paler, insipid yellowy green.


A green pigment located within the chloroplasts of plants

In PS I, the electrons are again excited by harnessing the energy from photons, and the reduction of NADP to NADPH2 is achieved by utilizing electrons and protons.



Stroma is the site for the dark or light-independent reactions of photosynthesis.

8.2 Chlorophyll And Chloroplasts Flashcards | Quizlet

Chlorophyll is the molecule that traps this 'most elusive of all powers' - and is called a photoreceptor. It is found in the chloroplasts of green plants, and is what makes green plants, green. The basic structure of a chlorophyll molecule is a , co-ordinated to a central atom. This is very similar in structure to the group found in , except that in heme the central atom is iron, whereas in chlorophyll it is magnesium.

What Is the Importance of Chlorophyll for Photosynthesis?

The chlorophyll molecule is the active part that absorbs the sunlight, but just as with hemoglobin, in order to do its job (synthesising carbohydrates) it needs to be attached to the backbone of a very complicated protein. This protein may look haphazard in design, but it has exactly the correct structure to orient the chlorophyll molecules in the optimal position to enable them to react with nearby CO2 and H2O molecules in a very efficient manner. Several chlorophyll molecules are lurking inside this bacterial photoreceptor protein (right).

Chloroplasts Structure and Function Factsheet | …

The actual chemical equation which takes place is the reaction between carbon dioxide and water, powered by sunlight, to produce and a waste product, oxygen. The glucose sugar is either directly used as an energy source by the plant for metabolism or growth, or is polymerised to form , so it can be stored until needed. The waste oxygen is excreted into the atmosphere, where it is made use of by plants and animals for respiration.

Difference between Chlorophyll A, B and Photosynthesis

Photolysis of water occurs in PS II, and it involves the dissociation of two water molecules to oxygen, protons and electrons by utilizing the energy from photons.