Energy changes can be represented using energy profiles. Catalysts (including enzymes) speed up chemical reactions. Energy changes can be calculated from bond energies.
If the energy change on an energy level diagram is negative, what does this tell you about the reaction?
It is endothermic
It is impossible
It is exothermic
What name is given to the minimum amount of energy needed by particles for them to react when they collide?
On a reaction profile, what does the height of the hump represent?
The activation energy
The energy change
The energy released when new bonds are made
What are enzymes made from?
How do catalysts work?
They give particles more energy
They lower the activation energy
They make new bonds in the reactants
Which statement is true of enzyme activity?
Enzyme activity depends on the number of collisions between the enzyme and substrate
Most enzymes are not sensitive to temperature
Extremes of pH are unlikely to denature an enzyme
Which is the most likely value for the optimum pH of an enzyme that breaks down protein molecules in the stomach?
Which model explains how an enzyme works?
Lock and key hypothesis
What happens to an enzyme at temperatures approximately 10°C above its optimum temperature?
It works more quickly
It is denatured
What can you deduce from the reaction profile below?
The reaction is endothermic
A catalyst is present
More energy is released than absorbed