A-B Flashcards
Acquired immunity
The portion of the immune system that encounters foreign substances (antigens) and learns the best way to attach each antigen and begin to develop a memory for that antigen
ACTH (adrencorticotropic hormone)
A polypeptide hormone produced and secreted from the anterior pituitary gland; increases release of cortisol from the adrenal cortex
Actin
A thin protein that forms (together with myosin) the contractile filaments of muscle cells, and is also involved in motion in other types of cells
Action potential
A temporary alteration of the transmembrane voltage (membrane potential) across the excitable membrane in a cell (such as neuron or myocyte) generated by the movement of ions through voltage-gated ion channels embedded in the membrane
Active site
The portion of an enzyme that is directly involved in binding substrate(s)
Active transport
The movement of a substance against its concentration gradient (from low to high concentration)
Adaptive radiation
Process in which organisms diversify rapidly into a multitude of new forms, particularly when a change in the environment makes new resources available
ADH (antidiuretic hormone)
A polypeptide hormone released by the posterior pituitary gland after being made in the hypothalamus. It acts to increase water reabsorption in the kidney (collecting ducts and distal convoluted tubule)
It is also a vasopressin that constricts blood vessels.
Adipocytes
Cells that primarily compose adipose tissue, specialized in storing energy as fat. Also known as lipocytes and fat cells
Agonist
Any chemical that binds to a receptor that activates the receptor to produce a biological response
Albumin
A protein made by the liver. Its main function is to regulate the osmotic pressure of blood
Aldosterone
A steroid hormone produced by the adrenal cortex. It regulates the balance of water and electrolytes in the body, by increasing sodium reabsorption (and therefore water) in the kidney (distal tubule and collecting duct). This indirectly increases BP
Allosteric effect
Interactions between spatially distinct sites; usually causes a conformational change at another site (like active site)
Amphiphatic
Any molecule containing both polar (water-soluble) and nonpolar (not water-soluble) portions in its structure
Anabolic pathway
ATP- consuming
Anaphase
The stage of mitosis when chromosomes are split and the sister chromatids move to opposite poles of the cell
Antagonist
Any receptor ligand or drug that blocks or dampens agonist-mediated responses rather than provoking a biological response itself
Anterior pituitary
A portion of the pituitary (master gland) that secretes hormones that influence growth, sexual development, skin pigmentation, thyroid function, and adrenocortical function
- Growth hormone 2. thyroid stimulating hormone 3. adrenocorticotropic hormone 4. beta-endorphin 5. follicle stimulating hormone 6. luteinizing hormone 7. prolactin
Artery
A thick walled vessel that carries blood high in oxygen content away from the heart to the body (except pulmonary artery)
ATP
A nucleoside triphosphate used in cells as a coenzyme, often called the “currency” of intracellular energy transfer. Metabolic processes that use ATP as an energy source convert it back into is precursors
Autonomic nervous system
The portion of the CNS that controls involuntary actions, such as the beating of your heart, and the widening/ narrowing of blood vessels
Autotrophs
An organism that produces complex organic compounds from simple substances present in its surroundings, generally using energy from light or inorganic chemical reactions
AV node
A group of specialized cardiac muscle fibers located at the center of the heart, in the floor of the atrium, between the atria and ventricles. The AV node takes the signal from the Sinoatrial Node (SA) and then sends the electrical impulses from the atria to the ventricles
Bacilli
The genus of Gram-positive, rod-shaped bacteria
Barr body
An inactive X chromosome in female autosomal cells
Beta cells
A cell in the pancreas whose function is to store and release insulin
Binary fission
Prokaryotic fission, a form of asexual reproduction and cell division used by all prokaryotes, and some organelles within eukaryotic organisms (e.g. miochondria)
Cell replicates its DNA, then pinches in the middle to form 2 daughter cells
Blood flow pathway
Superior/ Inferior vena cava, right atrium, right ventricle, pulmonary artery, lungs, pulmonary veins, left atrium, left ventricle, aorta, body
Bohr effect
Hemoglobin-oxygen binding affinity is inversely related to pH and CO2. Increase in CO2 leads to decrease in pH leads to hemoglobin releasing oxygen.
Increase in CO2, H+ concentration, DPG, temperature
Bowman’s capsule
A thin-walled sack-like structure which surrounds the glomerulus. It serves as a filter to remove organic wastes, excess inorganic salts, and water
Apoenzyme
Inactive enzyme. Needs to bind to cofactor to activate. It then becomes a holoenzyme
