| Krebs cycle | <biochemistry> Tricarboxylic acid cycle or citric acid cycle. (18 Nov 1997) |
|---|---|
| Krebs-Henseleit cycle | The metabolic pathway isfound in vertebrates and takes place in theliver, in it, urea is synthesised from amino acids and carbon dioxide. (09 Oct 1997) |
| Krebs-Kornberg cycle | A catabolic cycle in plants and microorganisms like that of the tricarboxylic acid cycle in animals; its key reaction is the condensation of acetyl-CoA with glyoxylic acid to malic acid (analogous to the condensation of acetyl-CoA and oxaloacetic acid to form citric acid in the tricarboxylic acid cycle). Synonym: Krebs-Kornberg cycle. (05 Mar 2000) |
| forced cycle | <cardiology, physiology> A cardiac cycle (atrial or ventricular) that is cut short by a forced beat. (05 Mar 2000) |
| fuel cycle | The series of steps required to produce electricity. The fuel cycle includes mining or otherwise acquiring the raw fuel source, processing and cleaning the fuel, transport, electricity generation, waste management and plant decommissioning. (05 Dec 1998) |
| futile cycle | <biochemistry> Any seqence of enzyme catalysed reactions in which the forward and reverse processes (catalysed by different enzymes) are consititutively active. Frequently used to describe the cycle of phosphorylation and dephosphorylation of phosphatidyl inositol derivatives in cell membranes. (05 Jan 1998) |
| levelised life-cycle cost | The present value of the cost of a resource, including capital, financing and operating costs, expressed as a stream of equal annual payments. This stream of payments can be converted to a unit cost of energy by dividing the annual payment amount by the annual kilowatt-hours produced or saved. By levelizing costs, resources with different lifetimes and generating capabilities can be compared. (05 Dec 1998) |
| life cycle | The entire life history of a living organism. (05 Mar 2000) |
| life-cycle costing | A method of comparing costs of equipment or buildings based on original costs plus all operating and maintenance costs over the useful life of the equipment. Future costs are discounted. (05 Dec 1998) |
| life cycle stages | The continuous sequence of changes undergone by metamorphosing insects and other animals during the developmental process. (12 Dec 1998) |
| lytic cycle | The general life cycle of a lytic virus, from infection of the host cell, hijacking of the host cells mechanisms, use of the host cells mechanisms to produce viral components, and assembly of the components into progeny viruses, to the destruction of the host cell by rupturing its plasma membrane (lysis) and the release of the progeny viruses so that they can spread and infect other cells. (09 Oct 1997) |
| aaa disease | Endemic anaemia of ancient Egypt, ascribed in the Papyrus Ebers to intestinal infestation with ancylostoma; now called ancylostomiasis. (05 Mar 2000) |
| ABO haemolytic disease of the newborn | Erythroblastosis foetalis due to maternal-foetal incompatibility with respect to an antigen of the ABO blood group; the foetus possesses A or B antigen which is lacking in the mother, and the mother produces immune antibody which causes haemolysis of foetal erythrocytes. (05 Mar 2000) |
| accumulation disease | A disease characterised by abnormal accumulation of a metabolic product in certain cells and tissues; examples include the mucopolysaccharidoses, lipoidoses. (05 Mar 2000) |
| Acosta's disease | A condition that results from prolonged exposure to high altitude. Symptoms include a continuous dry cough, shortness of breath, poor exercise tolerance, dizziness, headache, sleep difficulty, anorexia, confusion, fatigue and a rapid pulse. Treatment includes the immediate movement to a lower altitude. Prophylaxis has been accomplished successfully with the use of acetazolamide (Diamox). (27 Sep 1997) |