Metabolism: The Interconnected Web of Chemical Reactions in Living Organisms

Metabolism is the sum of all chemical reactions that occur in a living organism, with the primary goal of converting food into energy to power cellular processes.

Photosynthesis is the process by which plants convert light energy into chemical energy, while catabolism, anabolism, and gluconeogenesis are all types of metabolism that occur in living organisms.

Enzymes are biological catalysts that increase the rate of chemical reactions in living organisms by lowering the activation energy required for the reaction to occur.

Glycolysis is the first step in cellular respiration, where glucose is broken down into pyruvate, releasing energy in the form of ATP.

Oxygen is the final electron acceptor in the electron transport chain, where it combines with electrons and hydrogen ions to form water.

Acetyl CoA is a key intermediate in the Krebs cycle, where it combines with oxaloacetate to form citrate, initiating a series of reactions that generate energy.

The liver plays a crucial role in metabolism by storing and releasing glucose, maintaining blood sugar levels, and converting excess glucose into glycogen for storage.

Insulin is the primary hormone responsible for regulating blood sugar levels by promoting the uptake of glucose into cells and inhibiting the production of glucose by the liver.

Gluconeogenesis is the process by which glucose is synthesized from non-carbohydrate sources, such as amino acids and fatty acids, to maintain blood sugar levels.

Glucose is not a product of the Krebs cycle, which generates ATP, NADH, and FADH2 as high-energy molecules.

ATP (adenosine triphosphate) is the primary energy currency of cells, providing energy for various cellular processes through the hydrolysis of its phosphate bonds.

Fructose-1,6-bisphosphate is a key intermediate in glycolysis, where it is split into two three-carbon molecules, glyceraldehyde-3-phosphate and dihydroxyacetone phosphate.

The electron transport chain is responsible for generating ATP through oxidative phosphorylation, where electrons are transferred through a series of protein complexes, releasing energy that is used to pump protons across a membrane, creating a gradient that drives ATP synthesis.

Ribose-5-phosphate is a key intermediate in the pentose phosphate pathway, which generates NADPH and ribose-5-phosphate, a precursor for the synthesis of nucleotides and nucleic acids.

The urea cycle is responsible for converting toxic ammonia, a byproduct of protein metabolism, into urea, which is excreted in urine, thus eliminating nitrogenous waste from the body.