enzymes are biological catalysts (speed up a chemical reaction)
lock and key theory
A) substrate
B) active site
C) enzyme
D) enzyme-substrate complex
what makes an enzyme denature (change shape)?
high temperature
extreme pH
the enzyme doesn't work when it is denatures as the substrate can't fit into the active site
digestive enzymes are produced by specialised cells in glands and in the lining of the gut
enzymes in digestion:
the enzymes pass out of the cells into the digestive system
they come into contact with the food molecules
they catalyse the breakdown of large insoluble food molecules into smaller soluble molecules
amylase:
produced in the salivary glands and pancreas
a carbohydrate that breaks down starch into sugar (maltose)
test using iodine solution (turns blue-black)
protease:
produced in the stomach, pancreas and small intestine
breaks down proteins into amino acids
test using buret reagent (turns purple)
lipase:
produced in the pancreas and small intestine
breaks down lipids (fats) into fatty acids and glycerol
where is bile made and stored?
made in the liver and stored in the gall bladder
bile is an alkaline to neutralise hydrochloric acid from the stomach and emulsifies fat to form small droplets, increasing the surface area for enzymes to act on
