B4- summary

B4 summary 

Chemical reactions in cells

All living cells require energy from respiration 

Photosynthesis in plants makes food and energy available to food chains.

Enzymes are proteins that speed up chemical reactions.

They are assembled in the cytoplasm from the instructions carried by genes.

The chemical(s) that an enzyme works on is the substrate. 

This must be the correct shape to fit to the active site if the enzyme - the lock and key mechanism.

Each enzyme works best at an optimum temperature and pH.

The rate of an enzyme controlled reaction increases the temperature increases.

High temperatures and extreames of pH prevent enzyme action by changing the shape of the active site. (denaturing the enzyme)

Photosynthesis

Photosynthesis uses energy from sunlight to build large food molecules.

Light is absorbed by the green chemical chlorophyll

Chloroplasts contain chlorophyll and the enzymes needed for photosynthesis

The equation for photosynthesis is -------> Carbon dioxide + water ----(light energy)----> glucose + oxygen 

                                                                     -------> 6Co2 + 6H2O ----(light energy)----> C6H12O6 + 6O2

The glucose produced is converted to other chemicals that the plant…