AngelicaFaith B.Idanan

We had our online classes today and we had a discussion about Bioenergetics: The role of ATP. Learning about bioenergetics helped me understand how our bodies convert energy from the food we eat into ATP, which serves as the main energy currency of our cells. ATP provides energy for essential cellular activities, including muscle contraction, active transport across cell membranes, and the synthesis of important substances. I learned that energy from nutrients is used to produce ATP, mainly through oxidative metabolism, allowing our cells to continuously perform their functions. As a medical student, I can relate this lesson to my personal experience of feeling tired and overwhelmed by exams, quizzes, and deadlines. I realized that just as our cells need a continuous supply of energy to function properly, we also need to take care of ourselves by eating well, getting enough rest, and managing our energy. Just as ATP sustains essential processes in our bodies, having a clear purpose helps me stay motivated to continue my medical journey and become a doctor who can make a difference in the lives of others.

I find it amazing that our bodies are constantly working to produce energy and protect themselves, even when we are busy studying or sleeping. Sometimes, I feel like my brain is doing its own version of biologic oxidation during exam week. One thing I found interesting about biologic oxidation is how our bodies can perform so many chemical reactions without us even noticing. I learned that oxidation involves the loss of electrons, while reduction involves the gain of electrons by another substance. I also learned that different enzymes have specific roles in keeping our bodies functioning properly. This lesson reminded me that, just like our cells need protection from harmful substances, we also need to protect ourselves from too much stress and exhaustion. I realized that taking breaks and getting enough rest are not signs of laziness but important ways to care for ourselves. After all, even our cells work hard, but they also have systems to keep everything in balance.

Among the topics we discussed, I found the respiratory chain and oxidative phosphorylation more interesting because it showed me how our cells work like tiny power plants. I learned that the electron transport chain takes place in the inner mitochondrial membrane, where electrons from NADH and FADH₂ pass through different protein complexes. The energy released is used to pump protons across the membrane, creating a gradient that drives ATP synthase to produce ATP. I also learned that oxygen acts as the final electron acceptor, making it essential for this process. What made this topic even more enjoyable was how lively and fun the PowerPoint presentation looked. As a visual learner, I find colorful diagrams and illustrations more effective than simply reading long paragraphs. Seeing the process presented visually made it easier for me to follow the movement of electrons and understand how ATP is produced. Sometimes, a little color and creativity can make even the most complicated topics easier to understand and remember.

I never really thought about what happens to the food I eat after a meal until we discussed metabolism and metabolic fuels. I learned that carbohydrates provide a readily available source of energy, fats serve as long-term energy reserves, and proteins help build and repair body tissues. Our bodies can also adjust how they use these fuels depending on whether we have just eaten or have gone several hours without food. It’s amazing how our bodies have their own backup system to keep everything running .

Before discussing this topic, I thought carbohydrates were simply sugars that provide energy. However, learning about saccharides of physiologic significance helped me understand that carbohydrates come in different forms and serve various functions in our bodies. I found it interesting that glucose serves as an important energy source for our cells, while glycogen acts as an energy reserve that the body can use when needed. It reminded me of my eating habits, especially during exam week when I crave sweets to keep myself awake while studying. Sometimes, I feel like my brain is begging for a quick glucose boost just to get through another chapter.

Honestly, memorizing all the intermediates and enzymes sometimes feels like a cycle of its own. Thankfully, doc A gave us the mnemonic Can I Keep Selling Sweet For Money Officer. Just when I think I’ve memorized everything, I forget one step and have to start all over again. But learning the purpose behind each reaction helps me appreciate the topic beyond just memorization.

Keeping track of all the enzymes, reactions, and ATP yields sometimes makes me feel like my brain is going through glycolysis just to survive biochemistry. I used to think that eating something sweet was just a quick way to get energy, but learning about glycolysis and the oxidation of pyruvate helped me understand what actually happens inside our bodies. I learned that glycolysis takes place in the cytoplasm, where one glucose molecule is broken down into two pyruvate molecules, producing a net gain of 2 ATP and 2 NADH. When oxygen is available, pyruvate enters the mitochondria and is converted into acetyl-CoA, which then enters the citric acid cycle.

This topic reminded me of how I try to save my energy during busy exam weeks, although sometimes my only plan is to drink coffee and hope for the best. Learning about glycogen made me realize how important it is to have energy reserves, not just for our bodies but also in our daily lives. I found it interesting to learn how our bodies have their own way of storing extra energy for later use. Glycogen serves as the storage form of glucose, mainly in the liver and skeletal muscles. I learned that glycogenesis is the process of storing glucose as glycogen, while glycogenolysis breaks it down when the body needs energy. The liver helps maintain blood glucose levels, especially between meals, while muscle glycogen provides fuel for muscle contraction during physical activities. It’s like having an energy savings account that our bodies can use whenever needed.

One thing that surprised me about this topic is how our bodies can produce their own glucose when we haven’t eaten for a while. I learned that gluconeogenesis is the process of making glucose from non-carbohydrate sources, such as lactate, glycerol, and certain amino acids. The liver plays an important role in this process, especially during fasting, while hormones like insulin and glucagon help regulate blood glucose levels. It’s amazing how our bodies have their own way of keeping enough glucose available to support important organs, especially the brain.

There were moments when I felt like my brain needed its own backup energy just to keep up with all the enzymes and reactions! Even though I struggled with this topic, I realized that understanding the purpose of each product makes the pathway easier to appreciate. Among the metabolic pathways we discussed, the pentose phosphate pathway was one of the topics I found difficult to understand and memorize. Unlike glycolysis, this pathway does not directly produce ATP, which made it more challenging for me to understand its purpose at first.