Melvin Calvin won the Nobel Prize in Chemistry in 1961 for his studies on the Calvin cycle, also known as the Calvin-Benson cycle. The Calvin cycle is a biochemical pathway that occurs in chloroplasts of plants and other photosynthetic organisms. It is responsible for the fixation of carbon dioxide into organic compounds, such as glucose. The Calvin cycle is a complex process that involves many steps, but it can be summarized as follows:
- Carbon dioxide is fixed by ribulose bisphosphate carboxylase (RuBisCO) to form 3-phosphoglycerate (3-PGA).
- 3-PGA is phosphorylated to 1,3-bisphosphoglycerate (1,3-BPG).
- 1,3-BPG is reduced to glyceraldehyde 3-phosphate (G3P) using NADPH and ATP.
- G3P is used to regenerate RuBisCO, or it is exported from the chloroplast and used to build other organic compounds, such as glucose.
The Calvin cycle is a critical process for life on Earth. It is responsible for the production of oxygen, which is essential for aerobic respiration. The Calvin cycle also produces glucose, which is a source of energy for all living organisms.
The other options are incorrect because they are not related to the Calvin cycle. Light reaction is the first stage of photosynthesis, in which light energy is used to split water molecules into hydrogen ions and oxygen gas. Plant hormones are chemical messengers that regulate plant growth and development. Photons are particles of light.