Catalysts - Rate and Extent of chemical change Flashcards
What do reaction profiles show?
Energy changes - difference between energies of the reactants and products in a reaction.
What does the graph for an exothermic reaction look like?
Products are at a lower energy than the reactants.
The difference in height between reactants and products shows the overall energy change in the reaction.
The rise in energy at the start shows the energy needed to start the reaction. This is the activation energy.
What does the endothermic reaction graph look like?
Products are at the higher energy then reactants.
The difference in height shows the overall energy change during the reaction
The rise in energy at the start is the activation energy.
What do enzymes (catalysts) need?
Temperature and why do they need it to be right?
Right temperature
- if too hot some of the bonds holding enzymes together will break.
-This changes shape of the enzymes activation site, so substrate won’t fit anymore and enzyme is denatured.
5) All enzymes have a temperature they work best at - optimum temperature.
Why does catalysts need a certain PH?
PH can affect rate of reaction.
If it is too high or low it affects the bonds holding enzymes together together:
This changes shape of active site and denatured enzyme.
Called optimum PH - what they work best at.
