Investigating Digestive Enzymes

• Visking tubing is a good model for the gut. It lets small molecules through but not big ones. It is cheaper, easier and less yuky than an animals gut.
• Our guts are longer and have a massive surface area. It means the speed of digestion and absorption wil be sligtly different. 

• Add the same volume of starch suspension and 0.25% amylase solution to the visking tubing.
• Rinse the outside of tubing and put in to distilled water.
• Straight war test a drop of water from around the tubing with iodine soultion with Benedicts reagent and record coulour.
• Test the water again after 15 minutes and record the colour each time.
• Repeat the experiment using other concentrations of amylasse solution.

Orangey-brown colour means theres no starch in water due to the starch molecules being too big to pass through the visking tube.

Brick-red shows theres sugar in the warer because starch as been broken down by amylase to sugar and the molecules are smaller enough to pass through membrane in to water.

• The higher the concentration of amalayse, the faster the rate of reaction
• This is bigger because the more amalayse there is, the faster it breaks doen the starch