Photosynthesis - AQA Photosynthesis

Plants make their own food using photosynthesis. The food that plants produce is important, not only for the plants themselves, but for the other organisms that feed on the plants.

Part ofCombined ScienceBioenergetics

Photosynthesis

Plants, unlike animals, can make their own food. They do this using a process called .

During photosynthesis, plants produce from simple molecules – and water – using light energy.

The word and symbol equations for photosynthesis are:

Diagram illustrating the word and symbol equations for photosynthesis

Photosynthesis requires energy in the form of light to drive the chemical reaction. Photosynthesis is an reaction.

The light energy required is absorbed by a green called in the leaves. Chlorophyll is located in in , particularly the and spongy . Revise plant cells and their part in photosythesis here.

Plant leaves are the main photosynthetic , but any part of the plant exposed to the light will develop chlorophyll and photosynthesise.

The carbon dioxide required for photosynthesis comes from the air. It enters leaves through the . Water enters the plant through the roots, and is transported to the leaves in the .

Oxygen is formed as the waste product. Some is used for the plant's respiration, and also released which makes it available for respiration to animals and many microorganisms. During the day, provided the rate of photosynthesis is sufficiently high, plant leaves, and water plants, give out oxygen.

Biosynthesis

Some of the glucose produced by photosynthesis is used for .

Glucose is the starting point for the of materials that plants need to live.

The glucose not used for respiration is used in the following ways:

An image showing the cycle of gluecose.