Glucose Metabolism and Pyruvate Oxidation

The breakdown of glucose into pyruvate, generating ATP and reducing equivalents (NADH and H+).

The process of pyruvate being oxidized to acetyl-CoA in the presence of oxygen, using pyruvate dehydrogenase (PDH) as an enzyme.

An enzyme that catalyzes the conversion of pyruvate to acetyl-CoA, a key step in cellular respiration.

A molecule produced by the oxidation of pyruvate, used as fuel in the Krebs cycle.

A crucial coenzyme that carries electrons, vital for energy production in the electron transport chain.

The process of generating ATP through the transfer of electrons down an electron transport chain, driven by oxygen.

An organic molecule used by cells to store and release energy, utilized in various metabolic processes.

The process of maintaining a stable internal environment, including regulating glucose metabolism.

A measurement technique that estimates metabolic rate by indirectly measuring oxygen consumption and carbon dioxide production.

The ratio of carbon dioxide produced to oxygen consumed during respiration.

RQ values indicate the type of fuel being oxidized. A value of 0.7 indicates fat metabolism, 1.0 indicates carbohydrate metabolism, and 0.85 represents protein metabolism.

The amount of oxygen consumed per unit of ATP produced can vary depending on the fuel being oxidized. In the hummingbird example, it takes about 15-19% more oxygen to produce the same amount of ATP when burning fat compared to carbohydrates.

The metabolic rate required for hovering flight in hummingbirds is higher when they are fasted and burning fat, compared to when they are fed and burning carbohydrates, as they are less 'oxygen-efficient' when using fat.

The production of phosphocreatine is influenced by the ratio of substrate and product concentrations.

Phosphocreatine can move throughout the cell like ATP, carrying energy from where it's made to where it's needed.

Gluconeogenesis is the process of converting non-carbohydrate sources into glucose, primarily happening in the liver.

Gluconeogenesis and glycolysis are regulated to avoid simultaneous synthesis and breakdown of glucose, preventing wasteful energy cycles.

Metabolic pathways adjust to different energy demands, nutrient availability, and environmental conditions.

31P-NMR Spectroscopy measures ATP turnover, the dynamic change in ATP levels, rather than simply ATP consumption, which stays relatively stable in healthy cells.

31P-NMR Spectroscopy uses changes in NMR signals to detect shifts between ATP and inorganic phosphate, providing a detailed picture of energy dynamics.

31P-NMR Spectroscopy offers a comprehensive view of energy currency, considering both aerobic and anaerobic metabolic processes, and allows for real-time monitoring.

Hess's Law states that the overall energy released from the breakdown of a fuel is constant, regardless of the specific chemical steps involved, and eventually appears as heat.

A process that occurs when oxygen is unavailable, where pyruvate is converted into lactate by lactate dehydrogenase (LDH) to regenerate NAD+ for glycolysis. This allows continued energy production, but at a much lower rate than aerobic respiration.

A key enzyme in lactate fermentation that catalyzes the reversible conversion of pyruvate to lactate, allowing for NAD+ regeneration in anaerobic conditions.

A type of reducing equivalent shuttle that moves reducing equivalents (electrons) into mitochondria, crucial for ATP production during cellular respiration.

An important reducing equivalent shuttle primarily found in invertebrates. It utilizes the enzyme glycerol-3-phosphate dehydrogenase to transport electrons from NADH in the cytoplasm to FADH2 in the mitochondria.

A major reducing equivalent shuttle used by mammals and most vertebrates. It involves a series of enzymatic reactions using malate and aspartate to transport electrons from cytoplasmic NADH to the mitochondrial electron transport chain.

The process of breaking down glucose to produce energy in the absence of oxygen. While less efficient than aerobic respiration, it provides a rapid source of energy for short bursts of activity.

A crucial molecule involved in energy metabolism, carrying high energy electrons (reducing equivalents) and providing a source of energy for the electron transport chain within the mitochondria.

A class of organic compounds that are insoluble in water, characterized by their long chains of hydrocarbons.

A common arrangement of carbon atoms in lipids, characterized by a linear chain structure.

A common arrangement of carbon atoms in lipids, characterized by a cyclic (ring) structure.

Molecules composed of a long chain of carbon atoms with a carboxyl group at one end. They are a primary source of energy for the body and play crucial roles in cell structure and function.

Fatty acids without any double bonds between carbon atoms. These are typically solid at room temperature and are considered 'bad' fats.

Fatty acids that contain one or more double bonds between carbon atoms. These are liquid at room temperature and are considered 'good' fats.

The metabolic process that breaks down fatty acids into acetyl CoA, which is used to generate energy through the citric acid cycle.

A metabolic process that occurs in the mitochondria, where nutrients are converted into energy. It's a complex process that involves multiple steps and enzymes.

A type of metabolic process that is heavily reliant on oxygen to generate energy. It's key in many metabolic functions, including energy production and ATP synthesis.

The central metabolic pathway that oxidizes acetyl-CoA to generate energy, reducing equivalents (NADH and FADH2), and a small amount of ATP.

A series of protein complexes embedded in the inner mitochondrial membrane that uses electrons from NADH and FADH2 to generate a proton gradient, which is used to drive ATP synthesis.

The process of generating ATP by using the proton gradient across the mitochondrial membrane.

An alternative high-energy phosphate-containing molecule that can be quickly used to produce ATP.