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
Phosphorylation The process of introducing a phosphate group into a molecule, usually with the formation of a phosphoric ester, a phosphoric anhydride or a phosphoric amide.
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
Autophagy cellular catabolic process in which cells digest parts of their own cytoplasm
Ejaculation The expulsion of seminal fluid, thick white fluid containing spermatozoa, from the male genital tract.
Metabolism the set of life-sustaining chemical transformations within the cells of organisms
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
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).
Learning Any process in an organism in which a relatively long-lasting adaptive behavioral change occurs as the result of experience.
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
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
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.
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.
Menstrual cycle A type of ovulation cycle where the endometrium is shed if pregnancy does not occur.
Ageing A developmental process that is a deterioration and loss of function over time. Aging includes loss of functions such as resistance to disease, homeostasis, and fertility, as well as wear and tear. Aging includes cellular senescence, but is more incl
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).
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
Memory information stored in the mind, or the mental processes involved in receiving, storing, and retrieving this information