B4 ENZYMES Flashcards
catalyst is
A substance that speed up the rate of reaction but remains unchanged at the end of reaction.
biological catalyst is
A chemical that found in living organisms that acts as a catalyst
Explain why cells need enzymes.
Without enzymes, the metabolic reactions of a cell would happen too slowly for life process to continue.
Define the terms substrate and product.
A substrate is a molecule that an enzyme joins with at the start of reaction.
Substrate molecules are changed to product molecules during a reaction.
Describe how an enzyme causes a substrate molecule to change into product molecules.
The sequence of amino acids in the amino acid chain determines the way the chain will fold up to make the three-dimensional structure of the protein.
Explain what is meant by the active site of an enzyme.
The shape in an enzyme into which a substrate fits closely during a reaction.
Explain how the shape of the active site is related to the specificity of an enzyme.
Only a substrate with a shape that is complementary to the shape of the active site can fit into it. So, an enzyme can only work with a particular shape of substrate.
Describe the effect of the temperature on the rate of an enzyme-controlled reaction.
As temperature increase, the rate of the reaction will increase, up to maximum point ( the optimum) after which it will decreases rapidly as the enzyme is denatured.
Explain the effect of temperature on enzyme activity at temperature below the optimum.
The cooler molecules are, the slower they move.
So, the longer it takes for the enzymes and substrate molecules to bump into each other and the substrate to fit into the active site.
Therefore, the cooler the temperature, the slower the rate of reaction.
Explain the effect of temperature on enzyme activity at the temperature above the optimum.
As the temperature increases, the atoms in the enzyme vibrate more.
This changes the shape of the active site, making it more difficult for substrate to fit into the active site and so slowing down the rate of reaction.
Eventually, atoms vibrate so much that the shape of the active site is destroyed and the enzyme is denatured.
a type of carbohydrate enzyme produces in the mouth, which starts digestion of starch in food into simple sugar is
Amylase
digestive enzymes that break down proteins into smaller units is
proteases
digestive enzymes that break down lipids in foods is
lipases
an enzyme that released into the small intestine
trypsin
an enzyme that found in the stomach
pepsin
