How many light reactions are in photosynthesis?

two light reactions
The general features of a widely accepted mechanism for photoelectron transfer, in which two light reactions (light reaction I and light reaction II) occur during the transfer of electrons from water to carbon dioxide, were proposed by Robert Hill and Fay Bendall in 1960.

How many reactions must occur for photosynthesis to complete?

5.11C: The Two Parts of Photosynthesis. Light-dependent and light-independent reactions are two successive reactions that occur during photosynthesis.

What light reactions do photosynthesis need?

Photosynthesis occurs in two stages. Stage I is called the light reactions because it requires sunlight or artificial light. This stage uses water and changes light energy from the sun into chemical energy stored in ATP and NADPH (another energy-carrying molecule).

Is light required for all the reactions of photosynthesis?

The light dependent reaction of photosynthesis requires energy in the form of light so as to convert CO2 and H2O into glucose and other substrates. The light independent reaction does not require light but can also occur in the presence of light.

How many light reactions are needed for one glucose synthesis?

It would take six turns of the cycle, or 6 CO2​start text, C, O, end text, start subscript, 2, end subscript, 18 ATP, and 12 NADPH, to produce one molecule of glucose.

How many photons are required for photosynthesis?

– Eight photons of light are required to evolve one molecule of oxygen during photosynthesis. – As we already know, photosynthesis occurs in two stages- light-dependent reactions and light-independent reactions. – Light-dependent reactions require light as a source of energy.

What 2 reactions occur during photosynthesis?

Within the chloroplasts of a plant cell, photosynthesis occurs in two main phases: the light-dependent and light-independent reactions.

What are 3 reactions of photosynthesis?

Once in the mesophyll cells, CO2 diffuses into the stroma of the chloroplast—the site of light-independent reactions of photosynthesis (Figure 13.6. 1). The light-independent reactions (also known as the Calvin cycle) can be organized into three basic stages: fixation, reduction, and regeneration (Video 13.6.

What are the 3 reactions of photosynthesis?

Figure 1. Light reactions harness energy from the sun to produce chemical bonds, ATP, and NADPH. These energy-carrying molecules are made in the stroma where carbon fixation takes place. The light-independent reactions of the Calvin cycle can be organized into three basic stages: fixation, reduction, and regeneration.

How many enzymes are in photosynthesis?

One by one, three molecules of carbon dioxide are taken by RUBISCO and two other enzymes to produce one molecule of a three-carbon sugar called glyceraldehyde 3-phosphate. Two glyceraldehyde 3-phosphate molecules are eventually combined to make one molecule of glucose.

Is co2 required for light reactions in photosynthesis?

Photosynthesis absorbs light energy to build carbohydrates in chloroplasts, and aerobic cellular respiration releases energy by using oxygen to metabolize carbohydrates in the cytoplasm and mitochondria. Photosynthesis consumes carbon dioxide and produces oxygen.