B2 - Enzymes Flashcards
What type of digestive enzyme is amylase?
Carbohydrase
What does salivary amylase do in detail?
Breaks down starch molecules into the simple sugar maltose
What are the 3 environmental factors that are needed to ensure enzymes work properly?
Suitable pH
Temperature of 37 to 40 degrees
High concentration of the substrate
What is an enzyme?
Biological catalyst
What does every enzyme have and what does this do?
Active site
This is where the substrate fits in
What is a substrate?
The substance taking part in a reaction that needs to be catalysed
What is the lock and key hypothesis?
The theory that the active site of an enzyme fits only one type of substrate
What is maltase?
The enzyme that breaks down maltose into glucose
What does bile do and where does it come from?
Neutralises the acidity of food exiting the stomach and emulsifies fats
It comes from the liver and is stored in the gall bladder
How does the food pass from the small intestine to the blood?
The hair-like villi absorb products of digestion into the blood
What are enzymes a type of?
Protein
What are proteins made of?
Long chains of amino acids
What happens if an enzyme is in too high temperatures?
It will become denatured meaning that the active site will change shape so that the substrate will not fit to it
What is a catalyst?
A substance that increases the speed of reaction without being used up or changed
What does amylase do?
Converts starch into maltose and other sugars
What are the 3 places that amylase is made?
Salivary glands
Pancreas
Small intestine
What does protease do?
Converts protein into amino acids
What 3 places is protease made in?
Stomach (called pepsin)
Pancreas
Small intestine
What does lipase do?
Converts lipids (fat) into fatty acids and glycerol
What 2 places is lipase made in?
Pancreas
Small intestine
Describe the digestive system
The food is eaten and the salivary glands produce amylase in the saliva
The food passes down the gullet
It passes into the stomach which pummels the food with its muscular walls, produces pepsin (protease) and produces hydrochloric acid
The hydrochloric acid kills bacteria and gives the right pH for the pepsin to work (pH 2)
The food passes into the small intestine and the gall bladder releases bile into the small intestine and the pancreas produces protease, lipase and amylase enzymes and releases then into the small intestine
The digested food is absorbed through the walls of the small intestine into the blood
The remaining food passes into the large intestine where the excess water is absorbed out of it
The faeces are stored in the rectum until they pass out through the anus
How do biological detergents work?
They contain protease and lipase which break down animal and plant matter like food and blood
What is the advantage of biological detergents?
They are more effective at working at lower temperatures than other detergents
What 3 ways are enzymes used in foods?
Protease is used in baby food to pre-digest protein to make it easier for the baby to digest
Carbohydrases can be used to turn starch syrup into sugar syrup
Glucose syrup can be changed to fructose syrup using an isomerase enzyme. Fructose is sweeter than glucose so you can use less of it. Useful for slimming foods
How are enzymes used in industry?
Catalysts
What are the 4 advantages of using enzymes in industry?
They only catalyse the reaction you want them to
Using lower temperatures and pressures means lower cost
They work for a long time so they are cheap in the long run
Biodegradable so they cause less environmental damage
What are the 4 disadvantages of using enzymes in industry?
Some people develop allergies to enzymes
Can be denatured by even a small increase in temperature and see susceptible to poisons and changes in pH so the conditions have to be tightly controlled
Can be expensive to produce
Contamination of the enzyme with other substances can affect the reaction
What is the type of enzyme that speeds up DNA replication?
DNA polymerases
