1. Energy is the ability to do work. Work is the transfer of energy from one body to another. Metabolism is the sum of all anabolic and catabolic process in a cell or organism
6. Activation energy is the difference between the potential energy level of the transition state and the potential energy of reacting molecules.
7. Transition state in a chemical reaction is a temporary condition in which bonds within reactants are breaking and the bonds between products are forming.
8. Exothermic reaction results in a net amount of energy released, while endothermic reaction results in a net amount of energy absorbed. An example of exothermic reaction is combustion.
9. Entropy is a measure of the randomness or disorder in energy or in a collection of object.
12. The second law of thermodynamics – the entropy of the universe increases with any change that occurs.
13. Exergonic reaction is a chemical reaction in which the energy of the product is less than the energy if the reactant. This is related to exothermic reaction. Endergonic reaction is a chemical reaction in which the energy of the product is more that the energy of the reactant. This is related to Endothermic reaction
14. Metabolic reactions are reversible. When reversible reaction reaches equilibrium they become a dead cell.
16. Redox reaction is a chemical reaction involving oxidation (atom loses one or more electron) and reduction (gaining one or more electron). The substance that loses an electron is called reducing agent while the substance that gains an electron is called an oxidizing agent.
17. Enzymes are used to catalyze a reaction. Substrates are the reactant that an enzyme acts on when it catalyzes chemical reaction. Active site is the location where the substrate binds to an enzyme. The interaction between the substrate and the amino acids causes the protein to change its shape. This is known as the induced-fit model.
18. Enzyme requires cofactor or coenzymes to work properly.
19. Enzyme inhibitors are used to control enzyme activity. Enzyme activities can also be controlled by allosteric regulation. Feedback inhibition is a method of metabolic control in which product formed later in a sequence of reaction allosterically inhibits an enzyme that catalyzes a reaction occurring earlier in the process.
20. There are many commercial and industrial use of enzyme such as using proteases to coagulate milk for the manufacture of cheese.