Organisation Flashcards
What is an enzyme?
Biological catalysts produced by living things they are better than raising the temperature of a reaction as there is not a limit and it only speeds up useful reactions.
What is a catalyst?
A substance that speeds up the reaction without being changed or used up in the reaction.
Give the properties of enzymes
Enzymes are all large proteins that are made up of chains of amino acids. These chains are folded into unique shapes which enzymes need to do their jobs.
Explain how an enzyme catalyses a reaction
Every enzyme has an active site with a unique shape that only allows a certain substrate be catalysed.The active site binds to the substrate .
How does changing the temperature effect enzymes?
It increases the rate of reaction but if it gets too hot some of the bonds holding the enzyme together break. This changes the shape of the active site so the substrate won’t fit anymore.
What is the optimum temperature and pH of an enzyme?
It is the temperature they work best at. It also has an optimum pH it is often pH 7 neutral but enzymes such as pepsin which breaks down protein in the stomach works best at pH 2
What does the amylase enzyme catalyse?
Breaks starch down to maltose.
What solution do you use to test if starch is present?
Iodine - the solution will change from browny-orange to blue-black.
How do you investigate how pH affects enzyme activity?
Amylase activity:
- Put a drop of iodine solution into every well of the spotting tile
- Place a bunser burner on a heat proof mat with a tripod over it
- Put a beaker of water on top of the tripod and heat the water until it is 35 degrees C try to keep this temperature constant
- Add 1cm^3 of amylase solution and 1cm of a buffer solution with a pH of 5 into the beaker
- Wait 5 minutes
- Add 5cm of a starch solution to the boiling tube.
- mix the contents and start timing
- Use continuous sampling to record how long it takes for amylase to break starch down. Do this by every second add a drop of the mixture to the spotting tile.
- When the solution remains browny-orange starch is no longer present
- Repeat
- Calculate the rate of reaction using the formula Rate=1000/time
How do you calculate the rate of reaction?
Rate=change/time
What do digestive enzymes do?
They break down large molecules to smaller ones like sugars ,amino acids,glycerol and fatty acids. So the molecules can pass through the walls of the digestive system allowing them to be absorbed.
What is amylase?
It is an example of a carbohydrate. It breaks down starch.
Where is amylase produced?
The salivary glands
The pancreas
The small intestine
What is protease?
An enzyme that breaks down proteins into amino acids
Where is protease made?
The stomach
The pancreas
The small intestine
What is lipase?
An enzyme that converts lipids into glycerol and fatty acids
Where is lipase made?
The pancreas
The small intestine
What is biles function?
Bile is alkaline it neutralises the HCL - and turns the conditions alkaline - from the stomach so the enzymes work best within the small intestine. Bile also emulsifies fat so the fat breaks into small droplets. This gives it a much bigger surface area for lipase to work on which makes digestion faster.
Where is bile produced and stored?
Bile is produced in the liver. It is stored in the gall bladder.
How do the salivary glands help in digestion?
They produce amylase within the saliva witch breaks down starch.
What does the mouth do in the digestion system?
The teeth mechanically break down the food into smaller pieces with a larger surface area for enzymes to react faster. Then the tongue rolls the food into a bolus and pushes it to the back of the throat.
