Video Transcript
The diagram below shows the energy
needed for a chemical reaction to occur. How does a positive catalyst affect
this energy? (A) It will increase it, (B) it
will not affect it, or (C) it will decrease it.
The diagram provided is an energy
level diagram. It shows the relative energy of the
reactants and products. It also shows the amount of energy
that must be supplied in order for a reaction to occur. The question asks how a positive
catalyst would affect this amount of energy.
A positive catalyst is a substance
that increases the rate of a reaction without undergoing a permanent chemical
change. Lactase is an example of a positive
catalyst. Lactase serves an important role in
biological systems. Its job is to help break down
lactose, a large sugar molecule that is difficult for our bodies to digest. Lactose could break into smaller
sugars on its own, but this reaction is very slow because it requires a large amount
of energy. That’s where lactase comes in. Lactose binds to lactase, which
then breaks the large lactose molecule into smaller sugars. The reaction using lactase, a
positive catalyst, is much faster. This is because less energy is
required for the reaction to occur.
On an energy level diagram, the
energy at which a reaction occurs will be lower when a positive catalyst is
used. This means that when using a
positive catalyst, the energy needed for a reaction to occur will be lower. So, how does a positive catalyst
affect the energy needed for a reaction to occur? The answer is (C). It will decrease it.
