B1.2.4 Enzyme Reactions Flashcards
What factors affect enzymes?
- Temperature
- PH
- Concentrations of the enzyme and substrate
How does temperature affect enzyme controlled reactions?
At higher temperature, the enzyme and substrate molecules move faster and collide more often
In general, the higher the temperature, the faster the reaction
However, if the temp becomes too high, the enzymes denature
What happens when an enzyme denatures when temp is high?
The amino acid chains in the protein start to unravel, changing the shape of the active site
Now the substrate can no longer bind and so the rate of reaction decreases
What happens once all the enzyme molecules are denatured?
The reaction stops
Most denatured enzymes cannot return to their original shape. What kind of change is this?
An irreversible chemical change
How does PH affect enzyme controlled reactions?
- every enzyme has an optimum PH
-if PH is too high or too low may make the enzyme unfold, changing the shape of the active site
-then enzyme is denatured
Why could an increase in human body temperature lead to death?
-If the entire body’s temperature is too elevated, all the enzyme molecules may start to denature
-Meaning bodily reactions that we require to stay alive could stop working.
How does substrate concentration affect enzyme controlled reactions?
- In general, the higher the substrate concentration is, the faster the rate of the reaction
- but at a certain substrate concentration, all the enzyme molecules are bound to substrate molecules
- the rate of the reaction is at its maximum.
What happens to the rate of the reaction if there is a further increase in the number of substrate molecules?
The rate of reaction won’t increase as there are no enzymes for them to bind to
How does enzyme concentration affect enzyme controlled reactions? (3)
- In general, the higher the enzyme concentration, the faster the rate of the reaction
- However, this is limited by substrate concentration
- If no new substrate molecules are added, the reaction will stop
