Enzymes and food tests (in topic 1) Flashcards
What do enzymes do?
Speed up chemical reactions in living things.
What are catalysts?
Biological catalysts.
Proteins made up of long chains of amino acids (like all proteins).
What is the active site?
Region along the membrane that has a shape that fits with specific substrate molecules.
How does the enzyme speed up the reaction?
By locking onto the substrate at their active site.
Explain the lock and key theory.
Was believed that the substrate fit perfectly into the active site.
Explain the ‘induced fit’ model.
It was believed that substrate and active site fit perfectly but in reality, the active site changes shape a little as the substrate binds to it to get a tighter fit.
What is optimum temperature that enzymes work best at?
37 degrees (body temperature)
What happens to enzymes when it gets too hot?
Some of the bond holding the enzyme together break changing the shape of the active site so substrate won’t fit anymore. The enzyme is denatured.
How does pH effect enzymes?
If too high or too low, interferes with the bonds holding the enzyme together. This changes the shape of active site and denatures the enzyme.
What pH do enzymes work best at?
Often pH 7. Not always e.g enzymes in the stomach work best at pH 2.
Which enzyme breaks down starch and where is it made?
Amylase.
-pancreas
-small intestine
-salivary gland
Which enzyme breaks down protein and where is it made?
Protease.
-pancreas
-small intestine
-stomach
Which enzyme breaks down lipids (fats)? Where is it made?
Lipase.
-pancreas
-small intestine
What does starch break down into?
Maltose and other sugars.
What does protein break down into?
Amino acids
