To be sophisticated in biochemistry

To make some of the most difficult MCAT science passages fully intelligible and to make the hardest questions more clear (there are always easy questions too), a person may be called upon to demonstrate scientific knowledge and reasoning a step beyond 101 undergraduate level. As we have discussed, where the exam is most sophisticated is often within passages dealing with biochemistry and molecular biology. You cannot expect to earn a score higher than 130 in the science sections without being reasonably sophisticated in biochemistry. It's hard to argue with this, but what does that actually mean? Our own thinking behind the design of this course is bent on it. We are seeking it. With regard to biochemistry, what does it mean to be sophisticated in biochemistry?

From our perspective, a sophisticated understanding of biochemistry has a number of attributes. Firstly, the biochemistry knowledge must be communicating with your understanding of physics, general chemistry, and organic chemistry. Without tacit understanding from underlying science informing it, biochemistry facts turn into floating signifiers. They're hard to remember and don't mean all that much. Everyone memorizes 1,3-bisphosphoglycerate. It's an intermediate in glycolysis. You memorize the sound of the word, and you memorize the structure. But in the light of more fundamental physics and chemistry, 1,3-bisphosphoglycerate takes on the gestalt of a compressed molecular spring, just like ATP. This is physics, general chemistry, and organic chemistry speaking as a form of tacit knowledge. Concepts like electrostatic repulsion, Gibbs free energy, and nucleophilic acyl substitution all project onto the phosphate at the anhydride end. To understand 1,3-bisphoglycerate this way is to see the plot of glycolysis. The pathway has used the spontaneity of the catabolism of glucose to drive things to this point, powering the formation of phosphoryl transfer potential.

In other words, one aspect of sophistication in biochemistry is for biochemistry knowledge to integrate with fundamental underlying scientific concepts. However, there's another aspect of sophistication, another kind of conceptual integration in biochemistry. This is metabolic integration. From a systems levels perspective, the first type of integration looks downward towards fundamentals. Metabolic integration looks upwards towards the cellular and physiological levels.