Light-independent reactions Calvin cycle In the light ..

In the first phase of the Calvin cycle, carbon dioxide is fixed into a 6-carbon molecule, which splits into two, 3-carbon molecules. In the second phase (shown in this figure), the 3-carbon molecules are reduced to glyceraldehyde 3-phosphate (G3P), another 3-carbon molecule. Remember, reduction means that electrons are added to the molecule. NADPH, produced during the light reactions, provides the high-energy electrons for this process. Also in this reduction phase, some ATP is used. Thus, the Calvin cycle is energetically tied to the light reactions of photosynthesis.

In fixation, the first stage of the Calvin cycle, light-independent reactions are initiated; ..

2. The energy from ATP and the reducing power of NADPH (both produced during the light-dependent reactions) is now used to convert the molecules of PGA to glyceraldehyde-3-phosphate (G3P), another three-carbon compound. For every six molecules of CO2 that enter the Calvin cycle, two molecules of G3P are produced. Most of the G3P produced during the Calvin cycle - 10 of every 12 G3P produced - are used to regenerate the RuBP in order for the cycle to continue. Some of the molecules of G3P, however, are used to synthesize glucose and other organic molecules. Two molecules of the three-carbon G3P can be used to synthesize one molecule of the six-carbon sugar glucose. The G3P is also used to synthesize the other organic molecules required by photoautotrophs.


PHOTOSYNTHESIS: LIGHT REACTIONS AND CALVIN CYCLE

Thus, it is the Calvin cycle that makes sugar, but it can do so only with the help of the NADPH and ATP produced by the fight reactions.

Light reaction and photophosphorylation
Pigments embedded on thylakoid membranes form photosystems. There are of two types: PS I P700, PS II P680. Components of photosystem I and II transfer the electrons from water to NADP via cyclic electron transfer or non-cyclic electron transfer. During electron transfer, the light energy captured by the photosynthetic organisms is transformed into the phosphate bond energy of ATP. This is called photophosphorylation. NADPH is generated during non-cyclic electron transfer.


PHOTOSYNTHESIS Table of Contents ..

The energy from ATP and the reducing power of NADPH (both produced during the light-dependent reactions) is now used to convert the molecules of PGA to glyceraldehyde-3-phosphate (G3P), another three-carbon compound (see Fig. 1). For every six molecules of CO2 that enter the Calvin cycle, two molecules of G3P are produced. Most of the G3P produced during the Calvin cycle - 10 of every 12 G3P produced - are used to regenerate the RuBP in order for the cycle to continue (see Fig. 1). Some of the molecules of G3P, however, are used to synthesize glucose and other organic molecules. As can be seen in Fig. 1, two molecules of the three-carbon G3P can be used to synthesize one molecule of the six-carbon sugar glucose. The G3P is also used to synthesize the other organic molecules required by photoautotrophs (see Fig. 2).

The Light Reactions occur in the grana and the ..

The energy from ATP and the reducing power of NADPH (both produced during the light-dependent reactions) is now used to convert the molecules of PGA to glyceraldehyde-3-phosphate (G3P), another three-carbon compound (see Fig. 1). For every six molecules of CO2 that enter the Calvin cycle, two molecules of G3P are produced. Most of the G3P produced during the Calvin cycle - 10 of every 12 G3P produced - are used to regenerate the RuBP in order for the cycle to continue (see Fig. 1). Some of the molecules of G3P, however, are used to synthesize glucose and other organic molecules. As can be seen in Fig. 1, two molecules of the three-carbon G3P can be used to synthesize one molecule of the six-carbon sugar glucose. The G3P is also used to synthesize the other organic molecules required by photoautotrophs (see Fig. 2).

in the light-independent reactions

Light Cycle (Photosynthesis) Photosynthesis is the process in which chloroplasts absorb sunlight, and chlorophyll absorbs sunlight, with the help of water, then the thylakiod takes that sunlight and has 2 reactions.