Enzymes

Enzymes are made up of large proteins, and each have a particular shape. Each enzyme has an active site, which is the area in which other molecules can fit into.

Enzymes can either help with the building up small molecules into larger molecules or breaking down small molecules into

Enzymes are also called "biological Catalysts" as they can speed up reactions, especially in your body, this is because they lower the activation energy (the amount of energy necessary for a reaction to take place).

However, too high of a temperature means their active site will change shape and they cannot work anymore, this is called denaturing.  

When the temperatures are higher, the molecules can move around more quickly and with more energy, so successful collisions are more frequent. 

However the enzymes denature (change the shape of their active site) when the temperature becomes too hot, so they stop working.

Also enzymes also work better in certain pH conditions, if the conditions are too acidic or alkaline then the enzyme would again change shape and stop working.

In respiration:

Glucose + Oxygen => carbon dioxide + water ( + energy)

This process occurs mainly in the mitochondria of a cell.

The energy produced from this process is:

• Build up larger molecules from small ones.
• Allow muscles to contract
• Maintain a body temperature that is constant (in mammals and birds)
• Build up sugars, nitrates and other nutrients into amino acids, then proteins (in plants) 

Digestion is when insoluable molecules, that cannot dissolve in a solution, are broken down into soluable molecules. Some of the enzymes in digestion are:

+ Amylase catalyses starch into sugars in the mouth and the small intestine. Amylase is made in produced in the small intestine, the salivary glands, and the pancreas.

+Protease helps speed up the digestion of proteins into amino acids in the stomach and small intestine. Protease is made in the stomach, the small intestine and the pancreas.

+Lipase catalyses the breakdown of lipids, which are found in oily and fatty foods, to fatty acids and glycerol. Lipase is made in the small intestine and the pancreas.