See Also: vitamin K unit(medicine)
vitamin E unit(medicine)
vitamin A unit(medicine)
vitamin B2 unit(medicine)
vitamin B6 unit(medicine)
vitamin D unit(medicine)
vitamin C unit(medicine)
vitamin B1 hydrochloride unit(medicine)
Sherman-Bourquin unit of vitamin B2(medicine)
Herbal medicine (botanical medicine, herbology, phytomedicine)(health)

gradient perception (medicine) and vitamin C unit (medicine)


gradient perception (medicine)


gradient perception
<cell biology> Problem faced by a cell that is to respond directionally to a gradient of, for example: a diffusible attractant chemical.

In a spatial mechanism the cell would compare receptor occupancy at different sites on the cell surface, a temporal mechanism would involve comparison of concentrations at different times, the cell moving randomly between readings.

In pseudospatial sensing, the cell would detect the gradient as a consequence of positive feedback to protrusive activity if receptor occupancy increased with time as the protrusion moved up gradient. Few cell types have been unambiguously shown to detect gradients.


vitamin C unit (medicine)


vitamin C unit


The vitamin C activity of 0.05 mg of the standard crystalline levoascorbic acid; 1 mg of crystalline vitamin C provides 20 USP unit's.

See: Sherman unit.