Plants and Photosynthesis

Plants and Photosynthesis

1. Photosynthesis

   • Plants make food in their leaves by photosynthesis.
   • The raw materials for photosynthesis are carbon dioxide and water.
   • The light energy needed for photosynthesis is trapped by chlorophyll.
   • Chlorophyll is found in chloroplasts in green parts of leaves.

2. Biomass

   • A plant's biomass is the matter that is made of.

3. Respiration

   • Glucose from photosynthesis is used to make starch, to release energy during respiration and to make new materials.
   • Roots are branched and have root hairs to increase their surface area. They need oxygen to respire.
   • Plants use their roots to take up water and minerals such as nitrates.
   • Plant need nitrates to make proteins for making and respiring cells.
   • A plant uses water to cool its leaves, to swell up fruits, to make its cells firm and to stretch its cell growth.

4. Oxygen and Carbon Dioxide

   • Most photosynthesis happens in the cells near the to of the leaf.
   • About 21% of the air today is oxygen and about 0.03% is carbon dioxide.
   • Plants in oceans and forests help to maintain the balance of oxygen and carbon dioxide in the atmosphere.
   • Respiration, rotting and burning release carbon dioxide.