This is called photosynthesis, which means "making through light".

Photosynthesis consists of light-dependent and light-independent reactions.

Photosynthesis takes place in all plants that contain chlorophyll.

The action spectrum of photosynthesis is a graph showing the rate of photosynthesis for each wavelength of light. The rate of photosynthesis will not be the same for every wavelength of light. The rate of photosynthesis is the least with green-yellow light (525 nm-625 nm). Red-orange light (625nm-700nm) shows a good rate of photosynthesis however the best rate of photosynthesis is seen with violet-blue light (400nm-525nm).

Light Absorption for Photosynthesis - HyperPhysics …

For photosynthesis to occur, plants need: · Light energy from the sun · Chlorophyll to absorb light energy · Carbon dioxide from the atmosphere and from respiration in plant cells · Water which is absorbed by the roots and transported to the leaves by the xylem tubes....

An absorption spectrum is a graph showing the percentage of light absorbed by pigments within the chloroplast, for each wavelength of light. An example is the absorption spectrum of chlorophyll a and b. The best absorption is seen with violet-blue light. There is also good absorption with red-orange light. However most of the green-yellow light is reflected and therefore not absorbed. This wavelength of light shows the least absorption.


This process begins with the absorption of light by specialized ..

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Pigments absorb light used in photosynthesis.

The electrons from the chain of electron carriers are then accepted by Photosystem I. These electrons replace electrons previously lost from Photosystem I. Photosystem I then absorbs light and becomes photoactivated. The electrons become excited again as they are raised to a higher energy state. These excited electrons then pass along a short chain of electron carriers and are eventually used to reduce NADP+ in the stroma. NADP+ accepts two excited electrons from the chain of carriers and one H+ ion from the stroma to form NADPH.

The trapping of light energy is the key to photosynthesis

If the light intensity is not a limiting factor, there will usually be a shortage of NADP+ as NADPH accumulates within the stroma (see light independent reaction). NADP+ is needed for the normal flow of electrons in the thylakoid membranes as it is the final electron acceptor. If NADP+ is not available then the normal flow of electrons is inhibited. However, there is an alternative pathway for ATP production in this case and it is called cyclic photophosphorylation. It begins with Photosystem I absorbing light and becoming photoactivated. The excited electrons from Photosystem I are then passed on to a chain of electron carriers between Photosystem I and II. These electrons travel along the chain of carriers back to Photosystem I and as they do so they cause the pumping of protons across the thylakoid membrane and therefore create a proton gradient. As explained previously, the protons move back across the thylakoid membrane through ATP synthase and as they do so, ATP is produced. Therefore, ATP can be produced even when there is a shortage of NADP+.

Photosynthesis - Light, Absorption & Action Spectrum …

The process of chromatography, which separates complex mixtures into their component parts based on their solubility in different kinds of solvents, can help identify some of the pigments used in photosynthesis.

Absorption of Light by Chlorophyll - YouTube

Having isolated and identified pigments found in chloroplasts, you can now determine the wavelengths of light transmitted by each pigment and then by all the pigments in the chloroplast extract. There was a slight change from the laboratory manual during this exercise because we used an extract containing all the pigments as opposed to working with each pigment separately. A graph was constructed using the absorbance of the extract at varying wavelengths. The goal of this exercise was to discover at what wavelengths do the chloroplast pigments absorb the greatest amount of light. An ideal graph would be similar to the following: