Question

A plant is believed to be releasing oxygen during the night time. Do you believe that the statement is true? Justify your answer with reason.

Answer 1

Hint: Photosynthesis is the process by which the plants take carbon dioxide in the presence of sunlight and release oxygen during the day time. Carbohydrates are the end product of photosynthesis which is used in respiration by the plants.

Complete answer:
No, this statement is not true that a plant can release oxygen during night time. Plants release oxygen only during light reaction or the photochemical phase of photosynthesis because the sunlight is necessary for the breakdown of water ($H_2O$) molecules, which is the source of oxygen released. The light reaction is dependent on the light which occurs in the thylakoid membrane of the chloroplast. They are responsible for the generation of assimilatory power and the splitting of water during the day time. During the night time, there is no sunlight, and only dark reactions take place. These reactions are independent of light and they do not release oxygen.
- The reaction for photosynthesis:
$6CO_2 + 6H_2O + light\rightarrow C_6{H_1}_2O_6 + 6O_2$
- Maximum and minimum photosynthesis takes place in the blue and green light, respectively. Since the photosynthesis takes place in the chloroplast that has chlorophyll.
- The rate of photosynthesis is affected by the color of light that is absorbed the best by the chlorophyll pigment. Chlorophyll absorbs blue and red light energies with the greatest efficiency.
- The leaves of a plant are green because the chlorophyll within them absorb all other wavelengths of light and reflect only the green light.

Note:
- During the first stage of photosynthesis, the light energy from the sun is converted to chemical energy, which involves a series of chemical reactions known as the light- dependent reactions.
- Photosystems in plants are large complexes of proteins and pigments that perform the function to harvest light and play a key role in the light reactions. These two types of photosystems: photosystem I (PSI) and photosystem II (PSII).