Enzymes Flashcards
What are protein molecules made up of?
Long chains of amino acids
What does the shape of a protein depend on?
Its function
Complete the sentence:
The long chains of amino acids that make up proteins are…
…folded to produce specific shapes
What can proteins be in the body?
- Structural components of tissues (such as muscle)
- Hormones
- Antibodies
- Catalysts
What are chemical reactions in cells controlled by?
Proteins called enzymes
What are enzymes?
Proteins which act as biological catalysts
They increase the rate of reaction without being used up themselves
What is the ‘active site’?
The site/part of an enzyme where reactants bind
The area for other molecules to fit into
What is a substrate?
The molecule or chemical on which an enzyme acts
What can happen to the substrate held in the active site?
It can either be connected to another molecule or broken down
What can enzymes do?
- Build large molecules from many smaller ones (e.g. building starch from glucose)
- Change one molecule into another (e.g. convert one type of sugar into another)
- Break down large molecules into many smaller ones (e.g. digestive enzymes)
Why do enzyme reactions take place faster when it is warmer?
At higher tempertatures the molecules move around more quickly.
This means they collide with each other more often and with more energy
What happens when an enzyme becomes denatured?
The active site to change shape
This means the enzyme doesn’t work properly any more
What can cause an enzyme to denature?
If the pH is too acidic/alkaline
If the temperature is too great
Do all enzymes require the same pH?
No!
Do all enzymes work inside body cells?
No!
Digestive enzymes are produced in glands + the lining of the gut. They then pass out of these cells and come into contact with food
What is digestion?
The breakdown of large, insoluble molecules itno smaller, soluble ones
Describe the function of amylase
- A carbohydrase
- Catalyses the digestion of starch into sugars
- This is done in the mouth and small intestine
- It is produced by the salvary glands, pancrease, and small intestine
Describe the function of protease
- Catalyses the breakdown of proteins into amino acids
- This occurs in the stomach and small intestine
- It is produced in the stomach, pancreas, and small intestine
Describe the function of lipase
- Calalyses the breakdown of lipids (fats + oils) to fatty acids and glycerol
- This occurs in the small intestine
- It is produced by the small intestine and pancreas
What is glycerol?
A building block of lipids
How is digestion sped up in the stomach?
- Enzymes in the stomach work (such as protease) best in acidic conditions
- Glands in the stomach wall produce hydrochloric acid to create very acidic conditions
How is digestion sped up in the small intestine?
- Amylase and lipase work in the small intestine
- They work best when the conditions are slightly alkaline
- The liver produces alkaline bile which is stored in the gall bladder.
- This is then squirted into the small intestine to neutralise the stomach acid and make conditions slightly alkaline
How do biological detergents use enzymes and how does this make them useful?
- Contain proteases and lipases that digest food stains
- Work at lower temperatures then ordinary washing powders
- This saves energy and money spent on electricity
- Can be used to digest blood, grass, and gravy stains (yummy)
How can protease be used in industry?
To pre-digest proteins in some baby foods
This makes it easier for babies to get the nutrients they need to grow when they are learning to eat solid food
How is isomerase used in industry?
To convert glucose syrup into fructose syrup
Fructose is sweeter, so less is needed in foods
This means the foods are not as fattening
How is carbohydrase used in industry?
To convert starch into sugar syrup for use in foods
How are enzymes used in industry?
To bring about reactions at normal temperatures and pressures
Traditional chemical processes require expensive equipment and a lot of energy to produce high temperatures and pressures
What are the advantages of using enzymes?
- Enzymes in biological washing powders are very effective at removing stains such as blood, grass, and gravy
- Biological washing powders can be used at lower temperatures, reducing energy used and costs
- Some are used in medicine to diagnose, control, or cure disease
- In industry, costs of equipment and energy can be reduced
What are the disadvantages of using enzymes?
- People may have allergic reactions to washing powders on their skin. The enzymes are encolsed in capsules in the dry powder. Once the powder is dissolved, hands should not be placed in the water.
- Enzymes may enter waterways via the sewage system
- Industrial enzymes can be costly to produce
- Enzymes denature at the high temperatures needed to kill pathogens in washing
- Some fabrics, such as wool, will be digested by proteases
