All the biochemistry cycles and pathways
Welcome! I'm excited to help you master the elegant, interconnected web of biochemical pathways, from how our cells extract energy to how they build complex molecules.
To help me tailor this session specifically to your needs, could you tell me your current level of understanding of biochemistry and why you are interested in learning these pathways (e.g., for a college course, MCAT prep, or just personal interest)?
I'm studying for the MCAT and need to know the details.
Studying for the MCAT means we need to focus on both the conceptual logic and the high-yield details like rate-limiting steps, thermodynamics, and regulation. Since metabolic pathways are fundamentally about energy flow, we have to start with the foundational rules of biological traffic: bioenergetics and thermodynamics.
Your path
Carbohydrate Metabolism
The Citric Acid Cycle and Oxidative Phosphorylation
Lipid and Protein Metabolism
Metabolic Integration and Regulation
The Energy Currency and Biological Spontaneity
In biological systems, whether a chemical reaction occurs spontaneously depends on the change in (). On the MCAT, you must understand how cells drive non-spontaneous, unfavorable reactions () forward by pairing them with highly favorable ones (), a strategy known as reaction coupling.
For example, the first step of glycolysis wraps glucose in a phosphate group to trap it inside the cell. Adding a phosphate directly to glucose is thermodynamically uphill (), so the enzyme hexokinase couples this unfavorable step to the highly exergonic cleavage of ATP to ADP ().