Enzymes Flashcards
What are enzymes, and why do we need enzymes?
Enzymes are biological catalysts . Reduce the need for high temperatures and only speed up the useful chemical reactions
How do enzymes catalyse chemical reactions?
They lower the activation energy and provide an alternate route for the reaction to occur
What is the substrate(enzymes)?
The molecule being changed in the reaction
What do all enzymes have?
An active site that joins onto the substrate to catalyse the reaction
Why do enzymes only work with one substrate, and why are they said to have a high specificity?
Because for the enzyme to work the substrate has to fit into the active site.
If it doesn’t, then the reaction won’t be catalysed. This is called the lock and key mechanism.
What three factors affect the rate of reaction in enzymes?
Temperature, substrate concentration, and pH
What happens if the temperature is too hot for the enzyme?
Some of the bonds holding the enzyme together will break and change the shape of the active site. The enzyme is said to be denatured
What happens if the pH is too high for an enzyme?
Bonds holding the enzyme together will break, and active site will change shape. It is said to be denatured
How does substrate concentration affect the rate of reaction?
As there are more substrates, it is more likely that the enzymes will meet up with and react with a substrate molecule, and ROR will increase. However, it will stop increasing when all the active sites are full
What does denatured mean, and why do enzymes have an optimum pH?
When your active site no longer fits the substrate. Enzymes have an optimum pH because they are adapted to the pH in which they normally work.
Why do we need enzymes for digestion?
Some molecules are too big to fit through the walls of the intestine, so they are broken down into smaller and soluble molecules, which absorb into the bloodstream.
What does the enzyme amylase (carbohydrase) do?
Breaks down starch into Maltose and other sugars
What does protease enzymes do?
Breaks down proteins into amino acids
What does the enzyme lipase do?
Breaks down lipids into glycerol and fatty acids
What can enzymes do aswell as breaking down substances?
Synthesising them from their smaller components. Which means joining molecules together
