Essay on University of Phoenix

884 Words Apr 14th, 2014 4 Pages
Ashley Cooper
Biology 240 Week 1

Photosynthesis is the process in which plants convert light energy into chemical energy (glucose). Photosynthesis takes place in the chloroplasts of plants.

* The Light Dependent Reaction:
The light dependent reaction takes place in the membrane of the thylakoid membrane of a chloroplast and the lumen of the thylakoid. As light hits the thylakoid (the pigment) the Chlorophyll is absorbing the energy from the photons. Chlorophyll absorbs the red and blue light and reflects the green light. This is why most plants we see are green. Once chlorophyll absorbs enough energy, it releases two electrons. To replace the electrons chlorophyll uses light to split water into Oxygen
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The electron then moves to the protein called ferredoxin, which combines with NADH, the electron and hydrogen to produce NADPH. This is also need for the light independent reaction.

* The Calvin Cycle (Light Independent Reaction):
There are three phases of the Calvin cycle. Phase one which is also known as Carbon Fixation stage occurs when CO2 is incorporated into a five-carbon sugar called Ribulose Bisphosphate. This produces a six-carbon intermediate, which immediately splits in half to form two molecules of three phosphoglycerate. In the second stage known as the reduction stage ATP and NADPH2 from the ligt reactions are used to convert 3 phosphogylcerate to glyceraldehyde 3 phosphate, the three carbon carbohydrate precursor to glucose and other sugars. The last phase is the regeneration stage. More ATP is used to convert some of the glyceraldehyde 3 phosphate back to RuBP, the acceptor for CO2. This will complete the cycle.

* It is important to remember that the light reaction sustains the Calvin Cycle by generating ATP and NADPH2.

Cellular Respiration:
Cellular respiration allows organisms to use energy stored in the chemical bonds of glucose. The energy in glucose is used to produce ATP. Cells use ATP to supply their energy needs. Cellular respiration is a process, which the energy in glucose is transferred to ATP.

* Glycolysis:
Glycolysis occurs in the cytoplasm and does not require oxygen. During glycosis, a

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