Photosynthesis in Plants

Phototropins are blue-light receptors which are involved in phototropism. They are basically autophosphorylating protein kinases.

Melvin Calvin used radioactive Carbon-14 (C14) isotopes to trace the path of carbon in photosynthesis, leading to the discovery of the Calvin cycle. This work earned him the Nobel Prize in Chemistry in 1961. O18 is used in other photosynthesis experiments involving water splitting.

In C₄ plants, CO₂ is first accepted in mesophyll cell by phosphenol pyruvic acid, a 3-carbon compound and forms 4-carbon compound known as oxaloacetic acid.

Carbon dioxide is required in the process of photosynthesis. Plants prepare their food with the help of carbon dioxide, water and sunlight and release oxygen.

Chlorophyll is used as catalyst during photosynthesis.

This layer has cells which are loosely packed and are located just beneath the palisade mesophyll. It plays a vital role in holding the products of photosynthesis.

Insect pollinated flowers have sticky pollen, which sticks to pollinating agents such as insects. Light and feathery pollens are a characteristic of wind-pollinated flowers.

Oxygen is not needed for photosynthesis. It is released during this process.

The green pigment called chlorophyll helps to trap light energy.

The colour of Phaeophyta reflects the presence of the brown pigment fucoxanthin. It is a type of carotenoid found naturally in edible brown seaweed, which are used widely in Asian cuisine and also available as a nutritional supplement in capsule form. It is explored for weight loss, and to decrease insulin and blood glucose levels, etc. It may have anti-tumour effects also.

Gonyaulax, a species of Pyrrhophyta or dinoflagellates, can produce light and are responsible for much of the luminescence or phosphorescence seen in ocean waters at night when the water is disturbed. In the phosphorescent bays, high densities of a single species occur. Red tides are blooms, essentially monocultures of a given dinoflagellate species, which may or may not be luminous.

Carbon dioxide is converted into sugars in a process called carbon fixation.

Mesophyll cells, along with palisade and spongy cells, in a leaf are the principal centres of photosynthesis.

Dark reaction of photosynthesis utilises CO₂. Dark reactions make use of organic energy molecules (ATP and NADPH). This reaction cycle is also called Calvin Benison Cycle, and it occurs in the stroma. ATP provides the energy, while NADPH provides the electrons required to fix the CO₂ (carbon dioxide) into carbohydrates.

Burning is the opposite reaction to photosynthesis. Burning requires oxygen and releases the water and carbon dioxide.