Nucleophiles and Electrophiles
Bioenergetics and Cellular Respiration
Integration of Metabolism
The Digestive System and Nutrition
|Here is a little discussion about nucleophilic carbon in a more advanced context, the biochemical context. Read for comprehension. Thiamine pyrophosphate (TPP) is a prosthetic group for three crucial enzymes: pyruvate dehydrogenase (glycolysis), α-ketoglutarate dehydrogenase (citric acid cycle), and transketolase (sugar interconversion mechanisms). TPP serves as a source of nucleophilic carbon for these enzymes. TPP can be easily ionized to present a carbanion for addition to carbonyl groups. This serves to activate the group for further transformations, such as oxidative decarboxylization.|
The paragraph above goes a step or two beyond the MCAT level factual basis. It is not meant to say 'Here's what you have to know'. Don't worry that the occasionally dense level of biochemistry in these Interdisciplinary Discussions. It doesn't mean that you must remember a host of biochemical pathways for the MCAT. MCAT passages are fond of biochemistry, but the test-writers want to see if you have the basis in the fundamentals to hang on to the discussion. For MCAT review, treat this species of Interdisciplinary Discussion as a variety of a reading comprehension exercise. These types of discussions (and there are more coming) are designed to deepen your interest and understanding of fundamental concepts by showing them within the kinds of contexts that MCAT passages may present. On the MCAT, almost every question, even after the most dense passages, will depend on fundamental principles, not advanced knowledge.