Biology 104 Lecture 11 Questions Lecture 11 Questions 1. The vast majority of the energy used by living things on earth comes originally from the sun. Two major classes of metabolic reactions are referred to as degradation and synthesis. There are only a few enzymes, because an individual enzyme can function in many different reactions.
Enzymes increase the rates of reaction.
An important principle of the second law of thermodynamics states that energy can be transformed into matter and, because of this, we can get something for nothing. An allosteric enzyme has an active site where substrate molecules bind and another site that binds with intermediate or end-product molecules. An enzyme and a membrane receptor molecule are similar in that they are always attached to membranes. We could say that energy of activation is released when a large molecule breaks up. It changes the enzyme's shape.