Enzyme Action Flashcards
What is an enzyme?
Biological catalysts that speed up chemical reactions without being used up in the reaction.
What is activation energy?
Energy needed for a reaction to start.
How do enzymes lower the activation energy of a chemical reaction?
By forming an enzyme-substrate complex: this either holds two substrate molecules close together, reducing any repulsion between molecules allowing bonds to form more easily
OR
by putting a strain on bonds allowing substrate molecules to break apart more easily.
What is an enzyme-substrate complex?
It is when a substrate molecule fit’s into an enzymes active site. This relies upon the shape of the substrate bing complementary to the shape of the enzyme’s active site.
Describe the ‘lock and key’ model of enzyme action.
The shape of the substrate is an exact fit the shape of the enzyme’s active site allowing it to fit into the active site.
Describe the ‘induced fit’ model of enzyme action.
The shape of the substrate is complementary to the shape of the enzyme’s active site, on binding to the active site, the substrate triggers the enzyme’s active site to change shape slightly, forming an enzyme-substrate complex.
Explain why the enzyme maltase can only breakdown maltose and not starch.
Enzymes are specific, only maltose has a shape that is complementary to maltase’s active site, forming an enzyme-substrate complex.
