Topic 4 - Enzymes and digestion Flashcards
Definition of enzymes
Biological catalysts that lower the activation energy of a reaction without being used up themselves.
What are enzymes?
They are proteins (made up of lots of amino acids joined together) with a very specific shape
What are active sites?
Indents in enzymes with specific shapes that are complementary to the substrate
What are substrates?
the molecule that is complementary to and so fits the active site
What do substrates and active sites combine to form?
enzyme substrate complexes
What are factors affecting enzyme catalysed reaction?
Temperature
pH
What is the temperature at at which the reaction is happening the fastest called?
Optimum temperature
How does increasing the temperature make the rate of reaction become faster?
Increasing the temperature (until optimum):
- Increasing the temperature (until the optimum)
- Will increases the Kinetic energy
- Meaning more enzyme-substrate complexes are formed
- Meaning the rate of reaction becomes faster
- Increasing the temperature (above the optimum)
- Will increase kinetic energy
- So that the active site shape changes
- So that it is no longer complementary to the substrate
- Meaning less / no enzyme-substrate complexes are formed
- Meaning the rate of reaction will decrease
What is the optimum pH?
The pH at which the reaction is happening the fastest
How does increasing or decreasing the pH make the rate of reaction become faster?
-Increasing or decreasing the Ph above or below the optimum:
- Will cause the active site shape to change
- So that it is no longer complementary to the substrate
- Meaning less / no enzyme-substrate complexes are formed
- Meaning the rate of reaction will decrease
What is the definition of digestion?
Digestion is the breakdown of large insoluble molecules into small soluble molecules.
How does mechanical digestion take place in the digestive system?
teeth and stomach muscle which churn food
How does chemical digestion take place in the digestive system?
With enzymes
What substrate does the the enzyme amylase react with and what do they produce?
Substrate - starch
Product - maltose
What substrate does the the enzyme Maltase react with and what do they produce?
Substrate - Maltose
Product - Glucose
What substrate does the the enzyme Protease react with and what do they produce?
Substrate - Protein
Product - Amino Acids
What substrate does the the enzyme Lipase react with and what do they produce?
Substrate - Lipids
Products - Glycerol and fatty acids
Where is amylase made and released?
Made by salivary glands and released in the mouth.
Made by the pancreas released into the small intestine.
Where is Maltase made and released?
Made and found in the small intestine
Where is Protease made and released?
Made in and released
into the stomach
Made in the pancreas
and released into the
small intestine
Where is Lipase made and released?
Made in the pancreas
and released into the
small intestine
What is the function of hydrochloric acid in the stomach?
To lower the pH there so the protease enzymes have an optimum pH of 2
Where is bile produced, stored and released?
Produced - liver
Stored - Gall bladder
Released - Small intestine to neutralize the acid
What is the function of bile?
To neutralize acid in the small intestine to provide optimum pH for enzymes and to emulsify large fat droplets into smaller ones
