1. Nutrition in Flowering Plants
Y10 IGCSE Biology
Nutrition in Flowering Plants

2. Lesson 1
Understand the process of photosynthesis and its importance in the conversion of light energy to chemical energy (2.18).
Know the word equation and the balanced chemical symbol equation for photosynthesis (2.19).
Practical: Investigate the production of starch in photosynthesis (2.23).

3. Recap structure of a plant cell, circle chloroplasts
Recap structure of a plant cell, circle chloroplasts. Looking at photosynthesis. Intro photosynthesis.

4. Green plants make their own food using energy from sunlight.
Photosynthesis
Green plants make their own food using energy from sunlight.
This process is called photosynthesis (meaning made by light).
Carbon dioxide
taken up from air
Oxygen given
off as waste product
Glucose used for energy (respiration)
Glucose
Converted into starch and stored in plant until needed
Converted into cellulose which is a structural carbohydrate
Water - from soil

5. Photosynthesis
Green plants make their own food using light energy. They convert light energy to chemical energy (glucose = food) using a green pigment found inside chloroplasts in leaves called chlorophyll.
The light energy from the sun is trapped by the green pigment chlorophyll and used to join the raw materials (water and carbon dioxide) into the product glucose (a carbohydrate). The waste gas oxygen is given off.
Task:
Use this paragraph and your drawing to summarise photosynthesis in a word equation. A template has been provided to help you.
Use 1 colour for raw materials and another for the products. Remember to make a key.
RAW MATERIALS PRODUCTS
Light energy

6. CO2 + H2O ------> C6H12O6 + O2
Light energy
Carbon
dioxide
Water
Glucose
Oxygen
Chlorophyll
Glucose is used for energy, stored as starch or built up into
cellulose.
Oxygen is lost as a waste product
Products
Raw Materials
RAW MATERIALS
Essential requirement
PRODUCTS
Key:
This equation can be read as:
“carbon dioxide and water, in the presence of light energy and chlorophyll, produces glucose and oxygen”.
Like respiration, it can also be summarised in a chemical symbol equation. Can you write it? Can you balance it?
CO2 + H2O > C6H12O6 + O2
6CO2 + 6H2O > C6H12O6 + 6O2

7. The Fate of Glucose Can you remember?
It can be used in respiration to provide energy for growth etc.
It can be stored as a complex carbohydrate called starch. The starch can be broken down and converted back into glucose when it is required
It can be used by the plant as a structural carbohydrate called cellulose which is used to make cell walls.
Carbohydrates produced in photosynthesis can be used to produce fats and proteins.