Glossary A Flashcards
Abiotic conditions
A non living feature of an ecosystem
Abundance
The number of individuals of one species in a particular area
Accurate result
A result that is really close to the true answer
Acetylation
Attachment of an acetyl group to something.
Example: histones
Acetylcholine (ACh)
A type of neurotransmitter that binds to a cholinergic receptor
Acetlyl coenzyme A
(AcetylCoA)
A type of coenzyme involved in respiration. It transfers acetate from one molecule to another
Acquired mutation
A mutation you develop during your lifetime
Actin
A thin myofilament protein in muscle fibres
Actin-myosin cross bridge
The bond formed when a myosin head binds to an actin filament
Activation energy
The energy that needs to be supplied before a chemical reaction will start
Activator
A transcription factor that increases the rate of transcription
Active site
The part of an enzyme where a substrate molecule binds
Active transport
Movement of molecules and ions across plasma membranes, usually against a concentration gradient. Requiring ATP
Adaptation
A characteristic that increases an organisms chances of survival and reproduction
Example antibiotic-resistance
Adenosine diphosphate
(ADP)
A molecule made up of adenine, a ribose sugar and two phosphate groups. ATP is synthesised from ADP and the addition of a phosphate groups
Adrenaline
A hormone secreted from the adrenal glands that has many effects, including increasing blood glucose concentration.
Affinity for oxygen
A tendency a molecule has to bind with oxygen
Agglutination
The clumping of cells together
Example: pathogens, red blood cells
AIDS
(Acquired immunodeficiency syndrome)
A condition caused by HIV, in which the immune system deteriorates and eventually fails to
Allele
One or more alternative versions of the same gene
Allele frequency
How often an allele occurs in a population.
Allopatric speciation
Where speciation occurs as a result of geographic isolation
Alveolus
A microscopic air sac in the lungs where gas exchange occurs
Amino acid
A monomer of proteins
Ammonification
The process in which nitrogen compounds from dead organisms or waste material are turned into ammonium compounds by saprobionts
Anomalous result
A measurement that falls outside the range of values you’d expect it any pattern you already have
Antibiotic
A medicine that is designed to kill or inhibit growth of bacteria
Antibiotic resistance
When bacteria are able to survive in the presence of antibiotics
Antibody
A protein produced by B-cells in response to the presence of pathogens
Antidiuretic hormone
(ADH)
A hormone that regulates the water potential of the blood by controlling the permeability of the cells of the distal convoluted tubule and the collecting duct in the kidney
Antigen
A molecule (usually a protein) that can trigger an immune response
Antigenic variation
Where pathogens change their antigens
Antigen presenting cells
An immune system cell that process es and presents antigens on its surface to activate other immune systems cells
Antimicrobial substance
A substance designed to kill microorganisms
Example: antibiotic, antiseptic or disinfectant
Artefact (microscope)
Something you can see on a microscope slide that isn’t part of the specimen you’re looking at
Example: air bubble
Arteriole
A blood vessel that branches off an artery
Aseptic technique
A technique used to prevent unwanted growth or transfer of microorganisms
Atheroma
A fibrous plaque caused by build up and hardening of white blood cells, lipids and connective tissues
Adenosine triphosphate
A molecule made up of adenine, a ribose sugar and three phosphate groups. It is the immediate source of energy in a cell
ATP hydrolyse
An enzyme which catalyses the hydrolysis of ATP into ADP and P
ATP-phosphocreatine (PCr) system
A system that generates ATP very quickly by phosphorylating ADP using a phosphate groups from phosphocreatine
ATP synthase
An enzyme which catalyses the synthesis of ATP from ADP and P
Atrioventricular node
(AVN)
A group of cells in the heart that is responsible for passing waves of electrical activity from the SAN on to the bundle of His
Atrioventricular valve
A valve in the heart linking the atria to the ventricles
Attachment proteins (virus)
A protein on the surface of a virus that lets the virus cling onto a suitable host cell
Autonomic nervous system
A division of the peripheral nervous system that controls unconscious activities
Example: heart rate
Autoradiography
A technique that reveals the location of radioactive tracers
Autosomal linkage
When two genes are located on the same autosome and are inherited by offspring together
Autosome
A chromosome that isn’t a sex chromosome
