V Biology - Nutrition in Plants

Word equation for Photosynthesis

carbon dioxide + water —> glucose + oxygen

Balanced chemical equation for Photosynthesis

6CO2 + 6H2O —> C6H12O6 + 6O2

The process of Photosynthesis

• Light energy is used to split water, releasing oxygen gas and hydrogen ions.

• Carbon dioxide gas combines with the hydrogen to make glucose.

This is important in order for the plant to maintain/ gain energy and continue to grow

Use of Magnesium Ions

Chlorophyll

Magnesium Deficiency

Plant leaves appear yellow

Use of Nitrate Ions

Amino acids

Nitrate Deficiency

Poor growth and yellow leaves

Use of Mineral Ions

Growth

Bioaccumulation

Bioaccumulation occurs when toxins build up - or accumulate - in a food chain. The animals at the top of the food chain are affected most severely.

Biomagnification

The rise or increase in the contaminated substances caused by the intoxicating environment.

Causes of Eutrophication

Some pollutants affect the environment by disrupting the equilibrium in food chains:

• Sewage

• Nitrate Fertilisers

• Pesticides

Adaptations of the leaf for Photosynthesis

Adaption	Large surface area
Purpose	To absorb more light

Adaption	Thin
Purpose	Short distance for carbon dioxide to diffuse into leaf cells

Adaption	Chlorophyll
Purpose	Absorbs sunlight to transfer energy into chemicals

Adaption	Network of veins
Purpose	To support the leaf and transport water, mineral ions and sucrose (sugar)

Adaption	Stomata
Purpose	Allow carbon dioxide to diffuse into the leaf and oxygen to diffuse out

Adaption	Epidermis is thin and transparent
Purpose	To allow more light to reach the palisade cells

Adaption	Thin cuticle made of wax
Purpose	To protect the leaf from infection and prevent water loss without blocking out light

Adaption	Palisade cell layer at top of leaf
Purpose	To absorb more light and increase the rate of photosynthesis

Adaption	Spongy layer
Purpose	Air spaces allow gases to diffuse through the leaf

Adaption	Palisade cells contain many chloroplasts
Purpose	To absorb all the available light

Effect of Carbon Dioxide on rate of photosynthesis

Effect of Temperature on rate of photosynthesis

Effect of Light Intesity on rate of photosynthesis