The body cannot store excess amino acids, so they are used for protein synthesis or energy. During catabolism, nitrogen is converted into toxic ammonia, which the urea cycle safely removes. Remaining carbon skeletons are repurposed for fuel by producing glucose or acetyl CoA which are both catabolized to produce energy.

This podcast summarizes 5 key features of glycolysis: 1. Purpose of glycolysis ; 2. Tissues and Cellular compartments; 3. Energy output; 4. Regulation of rate-limiting enzymes; and 5. Clinical correlates (pyruvate kinase are deficiency).

This podcast explains how the human body adapts its metabolic pathways to manage pyruvate based on its nutritional status. In the well-fed state, high glucose levels allow pyruvate to fuel the TCA cycle for energy or assist in creating nonessential amino acids. Conversely, during fasting or physical exertion, the body shifts toward gluconeogenesis to synthesize new glucose from available resources. This process involves converting substances like lactate and alanine from the muscles back into pyruvate within the liver. Ultimately, the source highlights the body’s metabolic flexibility in maintaining energy balance through varying physiological conditions.

Insulin binding to its receptor initiates a cascade of intracellular events that lead to the activation of a phosphoprotein phosphatase. This phosphatase will dephosphorylate 8 distinct enzymes involved in carbohydrate and lipid metabolism and change their activity, thus changing the overall metabolism of carbohydrates and lipids.

In this short, the effect of allosteric effectors on enzyme kinetics is covered in some detail including the effect of allosteric effectors on either Vmax or the the enzyme's affinity for its substrate.

This podcast explains how elevated blood sugar levels trigger the release of insulin, a vital hormone that interacts with various body tissues. Once activated, insulin receptors initiate several internal processes designed to store energy and build cellular components. Specifically, this hormone facilitates anabolic reactions, which include converting glucose into glycogen and transforming fatty acids into triglycerides. Additionally, it plays a crucial role in protein synthesis by utilizing available amino acids. Ultimately, the source highlights insulin’s primary function as a coordinator for growth and energy storage within the body.

This podcast summarizes glycogen metabolim hidhlighting some of the major differences between liver and muscle glycogenolysis. In addition, allosteric and hormonal regulation of glycogenolysis in both tissues are covered in detail.

This podcast provides a detailed overview of metabolism, defining it as the complete set of cellular processes essential for survival, which are categorized into catabolic (energy-producing breakdown) and anabolic (energy-consuming synthesis) pathways. It emphasizes that metabolic regulation is heavily dependent on three main factors: hormone levels (particularly insulin and glucagon from the pancreas), the availability of substrates in the bloodstream, and input from the nervous system. The text further explains the metabolic shifts that occur during the well-fed state, where insulin dominates to promote glucose storage and uptake, versus the fasting state, where glucagon and stress hormones increase glucose production and shift tissues toward utilizing fatty acids and ketone bodies for energy. Specifically, the regulation of blood glucose by these key hormones is highlighted, demonstrating their antagonistic roles in maintaining energy homeostasis.

In nature, amino acids exist as two distinct isomers, designated D and L Isomers. These mirror images of one another are metabolized differently in the cell. Only L isomers are used in cellular protein synthesis. Most catabolic enzymes metabolize L-isomers only while D-isomers are metabolized by D-Amino acid oxidase.

This YouTube video transcript from "Metabolism Made Easy" highlights the significant role of fat reserves in the human body. The speaker emphasizes the substantial quantity of fat, primarily in the form of triacylglycerols (TAGs), stored within us. This reserve represents a considerable percentage of body mass and, crucially, an enormous energy depot. The transcript points out that the caloric potential of fat far surpasses that of both protein and glycogen, making it the body's most important long-term energy source.