NEET BIOLOGY

Detailed explanation-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.

Detailed explanation-2: -Chlorophyll is therefore said to “donate” an electron (Figure 5.12). To replace the electron in the chlorophyll, a molecule of water is split. This splitting releases an electron and results in the formation of oxygen (O2) and hydrogen ions (H+) in the thylakoid space.

Detailed explanation-3: -The light-dependent reaction takes place within the thylakoid membrane and requires a steady stream of sunlight, hence the name light-dependent reaction. The chlorophyll absorbs energy from the light waves, which is converted into chemical energy in the form of the molecules ATP and NADPH.

Detailed explanation-4: -A photon of light energy travels until it reaches a molecule of chlorophyll. The photon causes an electron in the chlorophyll to become “excited.” The energy given to the electron allows it to break free from an atom of the chlorophyll molecule. Chlorophyll is therefore said to “donate” an electron (Figure 5.12).

Detailed explanation-5: -Energy from sunlight is absorbed by the pigment chlorophyll in the thylakoid membrane. The energy is temporarily transferred to ATP and NADPH, which are used in the second stage of photosynthesis. Photosynthesis is a series of chemical reactions divided into two stages, the light reactions and the Calvin cycle.