Enzymes And Digestion Flashcards
What are enzymes
A biological catalyst that speeds up reactions without being used up itself
What is a enzyme made of
Proteins
How do enzymes work
The active site of an enzyme has a complimentary shape to a certain substrate meaning it is a tight fit allowing the enzyme to catalyse a reaction. The complimentary shape shows enzyme specificity, am enzyme will only work on one substrate.
What is the maximum rate of enzyme activity described as
Optimum level
What happens to enzymes and substrates at a low temp
They move slowly due to low kinetic energy. Therefore there is fewer collisions and enzyme activity is low
At what temp does maximum enzyme activity occur
Optimum temperature
What happens to an enzyme at higher temps than the optimum
They progressively denature. The higher temp changes the shape of the active site and it no longer fits the substrate
Each enzyme has a optimum pH on either side of this optimum why do they work less well
The incorrect pH changes the shape of the enzymes active site causing the complimentary fit to be less effective slowly down the rate of activity
What happens as more enzymes become available
More enzyme activity and concentration but it eventually will level off as the number of substrate molecules will become limiting
What is a inhibitor
A molecule or substance that fits loosely into an enzymes active site- they may not be the exact fit but will fit well enough to prevent normal substrates from using the enzyme. This will reduce the speed of reaction as enzymes being used by inhibitors are inactive
What is digestion
The breakdown of large, insoluble food molecules into small, soluble molecules that can be absorbed
What is absorption
The process in which small, soluble food molecules are transferred from the gut to the blood system. (In the ileum)
What are enzymes needed for in the digestive system
To break down large, insoluble food molecules into small, soluble ones that can be absorbed into the blood stream.
Where does most digestion of food take place
In the stomach and the first part of the ileum
What 3 enzymes are in the digestive system
Carbohydrase/ amylase
Protease
Lipase
What does amylase digest and what are the products of digestion
Digests starch
Produces glucose and other sugars
What does protease digest and what does it produce
Digests protein
Produces amino acids
What does lipase digest and produce
Digests fat
Produces glycerol and fatty acids
What is a catabolic reaction
Break down of large insoluble molecules into smaller soluble or molecules
What is a anabolic reaction
Build up of large molecules from smaller ones
What are enzymes made of
Amino acids, most a enzymes contain 100-1000 amino acids
The amino acids are joined in a long chain which is folded to produce a unique 3d structure
What is carbohydrase digest and produce
Digests carbohydrates to produce simple sugars
When a substrate collides with a molecule of the right enzyme and fits exactly into the active site what is this called
Enzyme-substrate complex
Explain the mouth in digestion
Teeth grinds food to increase surface area for enzyme action
Saliva is added by the salivary glands
It contains mucus ti lubricate to make it easy to swallow
It contains a digestive enzyme salivary amylase which helps break down starch into glucose