Question

Theconversion of.Pysocal energy of light and phosphate ions into chemical ewrgy

Answer 1

Photosynthesis takes place in two stages: the light-dependent reactions and the Calvin cycle. In the light-dependent reactions, which take place at the thylakoid membrane, chlorophyll absorbs energy from sunlight and then converts it into chemical energy with the use of water. The light-dependent reactions release oxygen as a byproduct as water is broken apart. In the Calvin cycle, which takes place in the stroma, the chemical energy derived from the light-dependent reactions drives both the capture of carbon in carbon dioxide molecules and the subsequent assembly of sugar molecules.

The two reactions use carrier molecules to transport the energy from one to the other. The carriers that move energy from the light-dependent reactions to the Calvin cycle reactions can be thought of as “full” because they bring energy. After the energy is released, the “empty” energy carriers return to the light-dependent reactions to obtain more energy. You should be familiar with the energy carrier molecules used during cellular respiration: NADH and FADH2. Photosynthesis uses a different energy carrier, NADPH, but it functions in a comparable way. The lower energy form, NADP+, picks up a high energy electron and a proton and is converted to NADPH. When NADPH gives up its electron, it is converted back to NADP+.

Answer 2

Photosynthesis takes in the carbon dioxide produced by all breathing organisms and reintroduces oxygen into the atmosphere. Photosynthesis is the process used by plants, algae and certain bacteria to harness energy from sunlight and turn it into chemical energy