In a reaction, the substrate has an energy of 40 kJ/mol, the transition state 120 kJ/mol and the…
Contributed by StemPy LabTry it on paper first. A hint, the key idea and the worked solution are here when you need them.
In a reaction, the substrate has an energy of kJ/mol, the transition state kJ/mol and the product kJ/mol. When an enzyme is present, the transition state is only kJ/mol. Find the activation energy without and with the enzyme, and the energy given out in going from substrate to product.
Need a reminder? The key ideaShow
An enzyme is a biological catalyst, almost always a protein. The substrate fits the active site: E + S gives ES, then EP, then E + P. The activation energy is the energy needed to reach the transition state. An enzyme lowers it and does not change the energy of the substrate or the product.
The worked solution
Have you tried it?
Work it out on paper first. It is fine to get stuck or make a mistake: that is how we learn. When you are ready, go through the solution one step at a time, and check each step against your own.
Step 1. Without the enzyme. kJ/mol.
Step 2. With the enzyme. kJ/mol.
Step 3. The energy given out. kJ/mol. The substrate and the product have the same energies with or without the enzyme, so this is the same in both cases.
Answer: kJ/mol without the enzyme, kJ/mol with it, and kJ/mol given out either way.
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