What is the process when plants take in sunlight, carbon dioxide and water allowing them to make sugar and oxygen?
The process you are referring to is called photosynthesis. It is the process by which plants, algae, and some bacteria convert sunlight, carbon dioxide, and water into glucose (a sugar) and oxygen. The process involves several steps:
1. Light Absorption: Plants have specialized structures called chloroplasts that contain a pigment called chlorophyll. Chlorophyll absorbs sunlight, particularly in the blue and red regions of the electromagnetic spectrum.
2. Light-dependent reactions: In this step, sunlight energy is converted into chemical energy in the form of ATP (adenosine triphosphate) and NADPH (nicotinamide adenine dinucleotide phosphate). This occurs in the thylakoid membranes inside the chloroplasts, where chlorophyll molecules capture light energy and transfer it to pigments in the reaction centers.
3. Water Splitting: During the light-dependent reactions, water molecules are split into oxygen, protons (H+ ions), and electrons. The oxygen is released into the atmosphere as a byproduct.
4. Calvin Cycle (Light-independent reactions): ATP and NADPH produced in the light-dependent reactions are used in the Calvin cycle to convert carbon dioxide into glucose. The Calvin cycle occurs in the stroma of chloroplasts.
5. Carbon Fixation: Carbon dioxide molecules combine with a five-carbon compound called RuBP (ribulose-1,5-bisphosphate) to form a six-carbon compound, which is then converted into two molecules of 3PGA (3-phosphoglycerate).
6. Reduction: The energy and electrons from ATP and NADPH produced in the light-dependent reactions are used to convert 3PGA into glyceraldehyde-3-phosphate (G3P), a three-carbon molecule.
7. Regeneration: Some of the G3P molecules are used to regenerate RuBP, allowing the Calvin cycle to continue. This step requires additional ATP.
Overall, the process of photosynthesis allows plants to capture sunlight energy and convert it into chemical energy in the form of glucose while releasing oxygen into the atmosphere.