Enzymes Flashcards
(14 cards)
What is an enzyme?
Enzymes are biological catalysts. They increase the rate of chemical reactions inside and outside cells.
What sorts of reactions do enzymes help speed up?
- Photosynthesis
- Respiration
- Making new proteins
In an enzyme, what does the substrate bind itself to?
The substrate binds itself to the active site.
What are two examples of enzymes at work?
- DNA polymerase - which breaks up the double helix before DNA replication. It is also involved in checking the copying of the DNA strand.
- Speeding up the rate of joining together the individual amino acids during protein synthesis.
What happens to enzymes at low temperatures?
At low temperatures, enzyme reactions are slow.
When is the enzyme at it’s maximum?
The enzyme is at it’s maximum level when it is at it’s optimum temperature.
What happens to the enzyme when it is put in a solution which is acidic or alkaline?
Making the solution more acidic or alkaline will slow the reaction down.
What is the average optimum pH for enzymes?
8
How well do enzymes work with substrate?
Enzymes will work best if there is plenty of substrate available. As the concentration of the substrate increases, so does the enzyme activity.
What happens to enzymes as the temperature increases?
As the temperature increases, so does the rate of chemical reaction. This is because heat energy causes more collisions, with more energy, between the enzyme molecules and other molecules. However, if the temperature gets too high, the enzyme is denatured and stops working.
Why are enzymes specific?
Enzymes are specific. Only molecules with the correct shape can fit into the enzyme. Just like only one key can open a lock, only one type of enzyme can speed up a specific reaction.
What happens to the enzyme at extreme temperatures or pH’s?
At extreme temperatures or pH’s, the enzyme will become denatured. Increasing the temperature to 60°C will cause a permanent change to the shape of the active site.
What happens when an enzyme becomes denatured?
Denaturing is a permanent change in shape of the protein molecule. It is caused by the breaking up of the hydrogen bonds that hold the structure together. A change in a protein’s shape will affect its activity because the active sit will change, so the substrate will no longer fit.
What is the optimum temperature for more enzymes?
40 degrees celsius.
