In its essence, photosynthesis is the process by which plants make
their chemical energy.
Most people think that the equation for photosynthesis is the complete
process, though there are several steps until the ATP can be made. To
produce ATP, light energy must first be captured. Within the leaf,
there are two sets of pigments that are responsible for this. The
first set is Chlorophyll;
Ã˜ Chlorophyll A which absorbs the yellow-green part of the spectrum
Ã˜ Chlorophyll B which absorbs the blue-green part of the spectrum
The second set is Carotenoids;
Ã˜ Î² Carotene which absorbs the orange in the spectrum.
Ã˜ Xanthophyll which absorbs yellow from the spectrum.
The reason for these pigments is that each pigment can absorb a
certain wavelength or group of wavelengths. Without these ...view middle of the document...
It is inside this thylakoid membrane that the
process begins, there is a Â‘funnelÂ’ in which at the bottom there is
primary pigment (Reaction Centre), along the side are many primary
pigments, these absorb the various different wavelengths in the light
and pass down the chemical energy down to the reaction centreÂ…this
ensures that no energy is lost during the process, it also makes the
process more efficient, as it ensures that no light energy passes
through without being harnessed.
There are two types of reactions, Light Dependant and Light
Independent. Light dependant is the more common reaction as the light
independent reaction only occurs when the light is made unavailable,
the light independent reaction is also known as the Calvin Cycle.
There are two photosystems involved in photosynthesis; Photosystem II
is responsible for the generation of a proton gradient used to
synthesize ATP. It is also responsible for oxygen evolution as
electrons are removed from water to replace those transferred to
photosystem I. Photosystem I is responsible for the production of
NADPH, although it can also operate in a mode which produces a proton
gradient, and thus ATP. The NADPH made in Photosystem II is then used
in the light independent reaction, if need be.
Photosynthesis is an essential chemical process that must take place
in order for organisms such as us to survive. The process of
photosynthesis releases oxygen and absorbs CO2 from the atmosphere
which maintains a balance within the atmosphere. This balance however
is being disrupted by the cutting down of trees, leading to excess
pollution in the air. The excess of these gasses is thought to be the
cause of the Greenhouse effect. The greenhouse effect has become more
and more apparent as our society has become increasingly industrially
based; this is due to factors such as deforestation. Plants are also a
primary source of energy, as animals cannot photosynthesise and so
consumed plants (phototrophs) for the energy that they produced.