Key Points

Photosynthesis is the process where green plants produce their own food, in the form of glucose, using sunlight, water, and carbon dioxide. This process is essential for the plant's growth and survival.

Four key components are required for photosynthesis: sunlight for energy, water ($\text{H}_2\text{O}$) absorbed by roots, carbon dioxide ($\text{CO}_2$) from the air, and chlorophyll, the green pigment that captures light.

The process of photosynthesis can be summarized by the word equation: Carbon dioxide + Water $\xrightarrow[\text{Chlorophyll}]{\text{Sunlight}} \text{Glucose} + \text{Oxygen}$.

The main product of photosynthesis is glucose ($\text{C}_6\text{H}_{12}\text{O}_6$), a sugar that provides energy. Oxygen ($\text{O}_2$) is released as a byproduct into the atmosphere.

Chlorophyll is the green pigment in leaves that absorbs sunlight energy. Because leaves are the primary site of photosynthesis, they are often called the 'food factories' of the plant.

Plants use glucose for immediate energy. Excess glucose is converted into starch, a complex carbohydrate, which is stored in various parts like leaves, roots (e.g., potatoes), and seeds for later use.

Stomata are tiny pores, typically found on the surface of leaves, which allow for the exchange of gases. Carbon dioxide ($\text{CO}_2$) enters the leaf and oxygen ($\text{O}_2$) exits through these pores.

Xylem tissue consists of thin tubes that transport water and dissolved minerals from the roots up to the rest of the plant, including the leaves where water is needed for photosynthesis.

Phloem tissue is another set of tubes that transports the food (glucose) made in the leaves to all other parts of the plant, such as the roots, stem, and fruits, for energy and growth.

Plants respire continuously to break down glucose and release energy for their life processes. This process uses oxygen and releases carbon dioxide, water, and energy.

The process of respiration in plants is summarized by the equation: Glucose + Oxygen $\rightarrow$ Carbon dioxide + Water + Energy. This occurs in all living cells of the plant.

Photosynthesis stores energy and produces food, occurring only in light. Respiration releases energy from food and occurs continuously. Photosynthesis consumes $\text{CO}_2$ and releases $\text{O}_2$, while respiration does the opposite.