B2a Flashcards
What are enzymes?
Proteins that catalyse chemical reactions in the body.
What is the lock and key theory?
A specific shaped active site which is only complementary to one substrate, the enzyme and substrate bond together.
What do enzymes do?
They control the rate of metabolism.
What do enzymes convert?
Insoluble food molecules into small soluble molecules that can be absorbed into the blood stream.
Food test: starch.
Iodine (brown/orange > blue/black)
Food test: carbohydrates.
Benedict’s solutions (blue > brick red)
Food test: protein.
Biuret reagent (blue > purple)
Food test: lipid.
Ethanol and water (clear > cloudy white)
What are all of the digestive organs?
Mouth, salivary glands, oesophagus, stomach, liver, pancreas, small intestine, large intestine, rectum, anus.
What does the liver do?
Make bile.
What does the pancreas do?
Make and release enzymes.
Enzyme: carbohydrase.
Breaks down carbohydrates
Produces simple sugars
Made in salivary glands, pancreas and SI
Enzyme: amylase.
Breaks down starch
Produces glucose
Made in salivary glands, pancreas and SI
Enzyme: protease.
Breaks down protein
Produces amino acids
Made in stomach, pancreas and SI
Enzyme: lipase.
Breaks down lipids
Produces glycerol and fatty acids
Made in pancreas and SI
Where is bile stored?
The gall bladder.
What does bile do?
Neutralises stomach acid (it is alkaline) for enzymes optimum pH in the SI.
Emulsifies lipids into small droplets for lipase to break down faster.
How does temperature effect enzymes?
If it is too high, it denatures.
If it is too low, it works slower.
How does pH effect enzymes?
If it is too high or low, it denatures.
What is denaturing?
When an enzyme’s active site changes therefore cannot bind to a substrate and catalyse the reaction.
