Enzymes Flashcards
What specific types of conditions do enzymes need to not denature?
- Specific Temperature
- Specific pH
What are the five rules for enzymes?
1) Always made out of protein
2) They can be used again
3) They speed up the rate of reaction (by lowering the activation energy needed)
4) Each enzyme catalyses one reaction
5) They are specific (their active site is the shape of the substrate only)
What is the lock and key mechanism?
The active site gives the enzyme a specific shape, but only accepts one type of molecules (substrate). If a substrate fits, it is complementary to the active site.
Def. Enzyme
Biological catalysts that speed up chemical (metabolic) reactions inside the body.
They only catalyse one reaction.
They have a specific shape to fit a speciic molecule, calle the active site.
Describe the process of the enzyme breaking down a substrate
1) The enzyme is near a substrate that happens to be complementary with its active site.
2) The enzyme joins with the substrate, creating an enzyme substate complex.
3) The enzyme releases the substrate, which has been broken down into products
How does an enzyme break down/catalyse a substrate?
It lowers the activation energy of the substrate so it can react more easily.
Describe a graph showing the effects of increasing temperature on enzyme activity, and then explain each stage
1) As the temperature increases, the enzyme activity increases because there is more energy, which facilitates reactions
2) Then, we get to the optimum peak, where enzyme activity is at it’s highest
3) If we keep increasing the temperature, the enzyme activity decreases, because the enzymes’ active sites denature (melt/deform) from the heat and the lock & key mechanism does not work anymore
What is the optimum peak for enzyme activity on the human body
37°C
Describe a graph showing the effects of increasing pH on enzyme activity
There is a peak over pH2 and a peak over pH7 (a bit wider than the other one). On either side of each of these peaks, there is an equal, extreme decrease. This is because if the enzyme is not in the right pH, too high OR too low, it denatures. There are two lines, representing two different types of enzymes that thrive in different pHs.
What enzymes function well in pH7?
Amylase
Others can be Trypsin, Lipase, Maltase, Sucrase and Lactase
Which enzyme functions well in pH2?
Pepsin
