A2 - AQA Biology (Unit 4) - Photosynthesis

Photosynthesis Notes
1. Overview
The leaf is the main photosynthetic structure.
The Chloroplasts are the cellular organelles within the leaf where photosynthesis takes place.
Leaves are adapted to allow in the materials for photosynthesis, Water, Carbon Dioxide and
Light, and is adapted to remove the products, Oxygen and Glucose.

Photosynthesis…

These photosystems are both part of the Light-Dependent Reactions in Photosynthesis.

2. The Light-Dependent Reaction (LDR)
As the name suggests, this reaction requires light, and is why light is needed during
Photosynthesis.
The LDR takes place within the Thylakoid membrane, making use of PS1 and PS2.
When light hits PS2…

3. The Light-Independent Reaction (LIR)
The LIR is also known as the Calvin Cycle.
The Calvin Cycle takes place in the Stroma of the Chloroplast, NOT the Thylakoid like the LDR.
ATP, NADPH and CO2 are used in this reaction.
The purpose of the Calvin Cycle is to reduce CO2…

4. Factors Limiting Photosynthesis
The ideal conditions for Photosynthesis vary between plant species, but the majority of species living
in the UK are best suited for the following conditions:
High light intensity of a certain wavelength.
o Light is needed to make NADPH and ATP in Photosynthesis. The higher the…