Question

Where does photosynthesis take place in plants?

Answer 1

Hint:Photosynthesis can be divided into two stages- the light dependent reaction and the light independent reaction. Special pigments in plant cell chloroplasts absorb the energy from certain light wavelengths, creating a molecular chain reaction called light-dependent reactions of photosynthesis.

Complete answer:
Plants are able to make their own food by using the energy from the sun. This process is known as photosynthesis. During this process, carbon dioxide from the atmosphere is taken in by leaves through stomata and used for making carbohydrates, mainly glucose and starch.

Photosynthesis consists of both light dependent and light-independent reactions. Light reaction occurs in plants inside the chloroplast thylakoids, where the pigments of chlorophyll are found. Within the chloroplast there is a membrane system consisting of grana, stroma lamellae and stroma matrix. This system is responsible for capturing light energy as well as for ATP and NADPH synthesis. In stroma, enzymatic reactions synthesise sugar, which in turn produces starch.

As light energy enters the pigment molecules, it energises the electrons inside them, and the thylakoid membrane shunts these electrons to an electron transport chain. Each step in the electron transport chain takes each electron to a lower energy state and uses its energy by ATP and NADPH production. Meanwhile, each chlorophyll molecule substitutes the missing electron with an electron of water; this method effectively separates water molecules to create oxygen.

After the light reactions occur, the light-independent or "dark" reactions occur in the stroma region of the chloroplast. In this process, also referred to as carbon fixation, the energy produced by the light reactions from the ATP and NADPH molecules drives a chemical pathway using carbon dioxide to produce a three-carbon sugar known as glyceraldehyde-3-phosphate $(G_{3}P)$.

Thus, Photosynthesis occurs in the chloroplast.

Note:Photosynthesis is essential for all living beings. Plants are the main producers of energy in the ecosystem. All other organisms depend on plants directly or indirectly for their food.