Metabolism

Metabolism - is made up of both catabolic and anabolic pathways. Metabolism explains how the cell is able to harnest energy from the food it consumes and how it is able to use this energy to survive by synthesizing essential molecules necessary for its survival.

In the MCAT, there are a few pathways which are greatly emphasized.

1. Glycolysis - This is conversion of glucose to pyruvate
2. TCA Cycle - This is the conversion of Pyruvate to acetyl Co-A and the ultimate oxidation to carbon dioxide
3. Oxidative Phosphorylation - This conveys how the cell harnesses the chemical energy in the bonds and how it uses this to synthesize the most essential molecule for survival: ATP.

Before we talk about the three pathways mentioned above, me must talk about enzymes. What are enzymes? What do they do? How are they so efficient? This portion might get a little too mathematical but it essential to understand why enzymes are so necessary for survival.