B2 Enzymes and Digestion (page 27) Flashcards
Enzymes used in digestion are produced by what?
they are produced by cells and then released into the gut to mix with food.
What do Digestive Enzymes break down?
Big Molecules.
What is classed as ‘Big Molecules’?
Starch, proteins and fats are BIG molecules.
Big molecules are too big to pass through the walls of the digestive system, so what breaks them down?
digestive enzymes break these BIG molecules down into smaller ones like sugars.
What do digestive enzymes break big molecules down into?
smaller ones like, sugars, e.g. glucose and maltose, amion acids, glycerol and fatty acids.
Once the digestive enzymes break down the big molecules into smaller ones, what happens?
the smaller soluble molecules can pass easily through the walls of the digestive system, allowing them to be absorbed into the bloodstream.
What are carbohydrases?
they convert carbohydrates into simple sugars.
Give an example of a carbohydrase?
Amylase.
What is Amylase?
Amylase is an enzyme - it can break down starch.
Where is Amylase made in the digestive system?
1) The salivary Glands
2) The pancreas
3) The small Intestine.
Give an example how starch is broken down?
Starch (which is a carbohydrate), »_space;»> Amylase Enzyme »_space;»»»>Maltose and other sugars, e.g. dextrins.
Please see diagram on page 27)
What is Maltose?
a sugar produced by the breakdown of starch by enzymes.
What is Proteases?
They convert Proteins into Amino Acids
What are proteins?
Protein is a molecule made up of aimo acids. (proteins are needed for the body to function properely. They are the basis of body structures, such as skin and hair, and other substances such as enzymes.
What are amino acids?
they are molecules that combine to form proteins. Amino acids and proteins are the building blocks of life.
Give an example how Proteins are broken down?
Proteins »_space;»»»» Protease enzymes »_space;»»> Amino acids
Where are Proteases made in the body?
1) The stomach (it’s called pepsin there)
2) The pancreas
3) The small intestine.
Lipases convert Lipids into what?
Glycerol and Fatty Acids.
What is Lipids?
They are fats and oils
Give an example how Lipid is broken down in the body?
Lipid »_space;»» Lipase enzymes»_space;»»> glycerole and fatty acids
Where are Lipases made in the body?
1) The pancreas
2) The small intestine.
The body makes good use of the products of digestion. What can they be used to make?
new carbohydrates, proteins and lipids. and some of the glucose (a sugar) that’s made is used in respiration (see page 54).
What is Bile?
Bile neutralises the stomach acid and emulsifies fats.
Where is Bile produced?
in the liver.
Where is Bile stored?
it is stored in the gall bladder before it’s released into the small intestine.
The hydrochloric acid in the stomach makes the pH too acidic or alkali? and why?
it makes it too acidic for enzymes in the small intestine to work properely.
Is Bile acidic or alkaline? and what do this mean?
Bile is Alkaline, this means it neutralises the acid and makes conditions alkaline.
(the enzymes in the small intestine work best in these alkaline conditions).
What is meant by Bile emulsifies fats?
Bile breaks the fat into tiny droplets. This gives a much bigger surface area of fat for the enzyme lipase to work on - which makes its digestin faster.
Bile is a product of the liver. Describe and explain its role in digestion? (4 marks)
Bile is alkaline, so it neuralises the stomach acid and makes conditions in the small intestine alkaline (1 mark)
The enzymes of the small intestine work best in these alkaline conditions (1 mark)
It also emulsfies fats/breaks down fats into tiny droplets (1 mark).
This gives a bigger surface area of fat for the enzyme lipase to work on, making digestion faster (1 mark).
What are Lipase?
it is an enzyme the body uses to break down fats in food so they can be absorbed in the intestines.
