Citric acid cycle A nearly universal metabolic pathway in which the acetyl group of acetyl coenzyme A is effectively oxidized to two CO2 and four pairs of electrons are transferred to coenzymes. The acetyl group combines with oxaloacetate to form citrate, which underg
Coagulation The sequential process in which the multiple coagulation factors of the blood interact, ultimately resulting in the formation of an insoluble fibrin clot; it may be divided into three stages: stage 1, the formation of intrinsic and extrinsic prothrom
Cell cycle The progression of biochemical and morphological phases and events that occur in a cell during successive cell replication or nuclear replication events. Canonically, the cell cycle comprises the replication and segregation of genetic material follow
Ejaculation The expulsion of seminal fluid, thick white fluid containing spermatozoa, from the male genital tract.
DNA replication The cellular metabolic process in which a cell duplicates one or more molecules of DNA. DNA replication begins when specific sequences, known as origins of replication, are recognized and bound by initiation proteins, and ends when the original DNA m
Sleep Any process in which an organism enters and maintains a periodic, readily reversible state of reduced awareness and metabolic activity.
Circadian rhythm any biological process in an organism that recurs with a regularity of approximately 24 hours.
Glycolysis The chemical reactions and pathways resulting in the breakdown of a carbohydrate into pyruvate, with the concomitant production of a small amount of ATP and the reduction of NAD(P) to NAD(P)H. Glycolysis begins with the metabolism of a carbohydrate t
Electron transport chain A process in which a series of electron carriers operate together to transfer electrons from donors to any of several different terminal electron acceptors to generate a transmembrane electrochemical gradient.
Cellular respiration The enzymatic release of energy from inorganic and organic compounds (especially carbohydrates and fats) which either requires oxygen (aerobic respiration) or does not (anaerobic respiration).
Action potential A process in which membrane potential cycles through a depolarizing spike, triggered in response to depolarization above some threshold, followed by repolarization. This cycle is driven by the flow of ions through various voltage gated channels with
Autophagy cellular catabolic process in which cells digest parts of their own cytoplasm
RNA splicing The process of removing sections of the primary RNA transcript to remove sequences not present in the mature form of the RNA and joining the remaining sections to form the mature form of the RNA.
Apoptosis A programmed cell death process which begins when a cell receives an internal (e.g. DNA damage) or external signal (e.g. an extracellular death ligand), and proceeds through a series of biochemical events (signaling pathway phase) which trigger an ex
Fermentation The anaerobic enzymatic conversion of organic compounds, especially carbohydrates, coupling the oxidation and reduction of NAD/H and the generation of adenosine triphosphate (ATP).
Metabolism the set of life-sustaining chemical transformations within the cells of organisms
Cognition The operation of the mind by which an organism becomes aware of objects of thought or perception; it includes the mental activities associated with thinking, learning, and memory.