Learn: Photosynthesis

Welcome!I've reviewed your growth areas and created this lesson to help you better understand photosynthesis. We'll explore what it is, why it's important, and some key concepts you need to know for the WJEC GCSE Biology specification.

What is Photosynthesis?Photosynthesis is the process plants use to make their own food. Using sunlight, carbon dioxide (from the air), and water, plants produce glucose and release oxygen as a by-product. This process is essential for life on Earth because it provides oxygen and energy for living organisms.

The Photosynthesis EquationThe word equation for photosynthesis is:Carbon dioxide + water → glucose + oxygenSunlight provides the energy needed for this chemical reaction, and the green pigment chlorophyll in the chloroplasts absorbs the light energy.

What is Glucose Used For?Plants use glucose for energy through respiration, and they can also store it as starch or convert it into other substances like cellulose for cell walls or oils for energy storage.

Limiting FactorsThere are three main limiting factors that affect the rate of photosynthesis: light intensity, carbon dioxide concentration, and temperature. These factors must be at the right levels for photosynthesis to happen efficiently.

Leaf Structure and AdaptationsLeaves are specially adapted for photosynthesis. They have a large surface area to absorb sunlight, chloroplasts containing chlorophyll, and stomata (small pores) for gas exchange. Water is transported to the leaves by the xylem, and glucose is transported away by the phloem.

Review Time!Great work! You've learned about photosynthesis, the key components, and factors that affect it. Let's test your understanding with a few review questions.