Glossary Flashcards
Abiotic
An ecological factor that is part of the non-living and physical environment of an organism.
Action potential
The depolarisation which takes her place across the cell surface membrane of a nerve cell during the passage of an impulse.
Acetyl co-enzyme A
An intermediate product formed during respiration during the link reaction.
Acetylcholine
A neurotransmitter involved in the transmission of impulses across synapses and released into the synaptic cleft when an impulse arrives at the membrane
Acrosome
An organelle in the head of a sperm that contains digestive enzymes which digests the follicle cells and jelly like layer of the egg, allowing the sperm to fertilise the egg
Action potential
The change in potential difference between inside and outside a nerve cell which takes place across the cell surface membrane during the the passage of an electrical impulse
Active artificial immunity
Immunity that develops following immunisation with antigens in a vaccine
Active transport
The movement of substances from an area of low concentration to an area of higher concentration against a concentration gradient, requiring ATP
Adhesion
A force resulting from attraction between molecules of different substances
Aerobic capacity
The ability to take in, transport and use oxygen - which determines our ability to undertake long periods of vigorous exercise
Agonist
A substance which mimics the action of a neurotransmitter at a synapse and fits into the receptor molecules for specific neurotransmitter e.g. Dopamine agonists used for Parkinson’s
Aneurysm
A weakening of the wall of an artery due to high blood pressure, which results in a balloon like swelling
APC
A phagocyte which carries antigens on its surface in order to trigger the specific immune system
Arthroscopy
Keyhole surgery on joints, during which a very small incision is made and a fibre optic tube and small surgical instrument are used to repair damage
Basal ganglia
A group of neurones within each cerebral hemisphere of the brain responsible for selecting and initiating stored programmes for movement
Biodiversity
The variety of living organisms in an habitat - both on a species level and a genetic levels (diversity of alleles present in a population)
Bipolar neurone
A type of nerve cell in the retina which has a cell body with a dendron and an axon
Blood clotting
The action of fibrinogen being converted to fibrin, which forms a mesh of protein fibres over the surface of a wound or a damaged artery
BMI
Body mass/height^2
Carbon fixation
The process which converts CO2 into carbon compounds such as GP, normally occurring during the Calvin cycle and catalysed by Rubisco
Cardiac output
The total volume of blood pumped out of the left verticale of the heart in one minute (stroke volume x bpm)
Carrier protein
A protein which binds with a specific ion or molecule and helps it cross a membrane
CD4 receptor
A receptor molecule found in the cell surface membrane of T helper cells which is complementary in shoe to the antigen fragment displayed by an APC
Centromere
The region on a chromosome where to chromatids are held together during mitosis and the spindle fibres attach
