Final answer:
Photosynthesis is the process that converts light energy into chemical energy, producing glucose and oxygen. It involves light-dependent reactions in the granum and a light-independent phase known as the Calvin cycle occurring in the stroma. This process is fundamental for the survival of plants and other living organisms.
Step-by-step explanation:
Photosynthesis is the process by which green plants harness light energy from the sun to convert it to the chemical energy of sugar. Using carbon dioxide and water during photosynthesis results in the manufacture of glucose and oxygen gas (as a by-product). Plants require essential nutrients such as carbon, hydrogen, oxygen, nitrogen, and magnesium for this process. Photosynthesis may be divided into two phases: the light-dependent reactions that occur in the granum and require the presence of light energy; and the light-independent phase/Calvin cycle or carbon fixation that occurs in the stroma with or without light.
The first phase, the light-dependent reactions, involves chlorophyll absorbing energy from sunlight and converting it into chemical energy with the aid of water, releasing oxygen as a byproduct. The chemical energy is stored in ATP and NADPH. These energy carriers are utilized in the second phase of photosynthesis. During the Calvin cycle, these energy carriers help convert carbon dioxide into glyceraldehyde-3-phosphate (GA3P), which can then be transformed into glucose, sucrose, or other sugar molecules. These sugar molecules are vital as they contain energy and carbon necessary for the survival of living organisms.