During photosynthesis, oxygen in glucose comes from A. Oxygen in air B. Water C. Carbon dioxide D. Both B and C?

Question

Answer

B)its from water ,it is proved by using radioisotopic techniques by Robert hill......

Answer

Answer is B.Water ..In green plants H2O is the H donor and oxidised to O2 . some organisms do not release O2 during photosynthesis . when H2S, instead is the H donor for purple & green sulphur bacteria , the oxidation product is SULPHUR or SULPHATE depending on organism & NOT O2. This was later proved by radioisotopic techniques.

Answer

During photosynthesis, oxygen in glucose comes from:

The process of photosynthesis involves the conversion of light energy into chemical energy in the form of glucose. Oxygen is released as a byproduct during this process. The oxygen atoms found in glucose ultimately come from two sources, namely water (H2O) and carbon dioxide (CO2).

1. Water as a source of oxygen:
- Water is one of the key reactants in photosynthesis. It is absorbed by plant roots and transported to the leaves through the xylem vessels.
- Water molecules are split during a process known as photolysis, which occurs in the thylakoid membranes of the chloroplasts.
- The energy from sunlight is used to split water molecules into hydrogen ions (H+), electrons (e-), and oxygen gas (O2).
- The released oxygen gas then diffuses out of the plant through tiny openings called stomata, which are mainly present on the leaves.

2. Carbon dioxide as a source of oxygen:
- Carbon dioxide is another reactant required for photosynthesis. It enters the plant through the stomata on the leaf surface.
- Inside the chloroplasts, carbon dioxide is converted into glucose through a series of chemical reactions known as the Calvin cycle or the dark reactions.
- During the Calvin cycle, carbon dioxide molecules are combined with hydrogen ions and electrons, which were generated during the light-dependent reactions.
- The oxygen atoms originally present in the carbon dioxide become incorporated into the glucose molecule.

3. Oxygen in glucose:
- Glucose is a carbohydrate molecule with the chemical formula C6H12O6.
- The oxygen atoms present in glucose come from both water and carbon dioxide.
- Specifically, six oxygen atoms in glucose come from water molecules, while the remaining six oxygen atoms come from carbon dioxide molecules.

Therefore, the correct answer is option D: Both B and C (Water and Carbon dioxide).

Answer

Oxygen in photosynthesis is mainly due to wate but also by carbondioxide. see c4 and c3 pathway o2 is one of the product of this cycle

Answer

Option c from CO2

Answer

Answer given CO2

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