Enzymes Flashcards
What is an enzyme?
- Enzymes have specific shape which fits one type of substrate
- Shape of active site v important - where substrate fits enzyme
- Only substrate that fits can be broken down
- Enzymes break down food into nutrients
- Enzymes are biological catalysts to speed up body’s chemical reaction
- All enzymes are large proteins made of chains on amino acids
- Enzymes play a role in metabolism
- Learn diagram
What is meant by an enzyme?
Enzymes are needed so that this breaking down happens quickly enough to be useful.
When do enzymes come into the digestive system?
Different enzymes are added by the digestive system at various stages.
There are different enzymes for different functions.
Name the digestive enzymes, jobs and where they work?
Carbohydrase or Amylase -> breaks carbohydrates like starch into sugar molecules. Made in the mouth (salivary glands), stomach, small intestine and pancreas. Works in mouth and small intestine
Lipase -> breaks fat into glycerol and fatty acids. Made in the small intestine and pancreas. Works in small intestine
Protease-> breaks protein into amino acids. Made in the stomach, pancreas and small intestine. Works in stomach and small intestine
Name one organ in the body where all the enzymes are released?
Small intestine
True or false: fats can be broken down into amylase?
Explain?
False
Amylase breaks down carbohydrates
Lipase breaks down fats
Why is it important to eat lots of fibre?
Digestive enzymes can’t break down fibre
So fibre can’t be absorbed by the body
Fibre helps digestive system-it passes straight through the system
look up full answer
What factors affect how well enzymes work?
Temperature around 37degrees is best. If higher it will denature meaning it’s shape changes and the shape cannot bind with enzyme
Enzymes have an optimum ph often it is 7 but not always
Eg Pepsin is best at ph 2
What is the only enzyme that works in the stomach?
Protease works in the stomach
How do enzymes work?
Work outside body cells
Produced by specialist cells in glands and gut lining
Released into the gut to mix with food molecules
Big molecules too large to pass through walls of digestive system
Enzymes break them down
Oxygen uses products of digestion and can make new carbohydrates, proteins and lipids.
Some glucose is used in respiration
What things are not digested and what does this mean?
Minerals, vitamins and water are small enough to be absorbed by the body
So they are not digested
They do not need to be broken down again
How does seaweed help digestion?
Alginate, found in seaweed, suppresses digestion of fat
Reduces lipase absorbing fat into the body
Even small amount reduces fat in take by 1/3
Alginate is a natural fibre
What is a substrate?
A substrate is a molecule on which an enzyme acts
What is an active site?
Where the substrate fits into the enzyme
What is a product?
When the enzyme and substrate combine the nutrients are broken down into products
