A unit of measurement of weight and mass in the metric system. In weight, a gram is equal to a thousandth of a kilogram. In mass, a gram is equal to a thousandth of a liter (one cubic centimeter) of water at 4 degrees centigrade.
The word “gram” comes from the Late Latin “gramma” meaning a small weight via the French “gramme.”
The abbreviation for gram is gm. Its symbol is g.
- Gram stain
The Danish bacteriologist J.M.C. Gram (1853-1938) devised a method of staining bacteria using a dye called crystal (gentian) violet. Gram’s method helps distinguish between different types of bacteria. The gram-staining characteristics of bacteria are denoted as positive or negative, depending upon whether the bacteria take up and retain the crystal violet stain or not. Gram-positive […]
Gram-negative bacteria lose the crystal violet stain (and take the color of the red counterstain) in Gram’s method of staining. This is characteristic of bacteria that have a cell wall composed of a thin layer of a particular substance (called peptidoglycan). The Gram-negative bacteria include most of the bacteria normally found in the gastrointestinal tract […]
Gram-positive bacteria retain the color of the crystal violet stain in the Gram stain. This is characteristic of bacteria that have a cell wall composed of a thick layer of a particular substance (called peptidologlycan). The Gram-positive bacteria include staphylococci (“staph”), streptococci (“strep”), pneumococci, and the bacterium responsible for diphtheria (Cornynebacterium diphtheriae) and anthrax (Bacillus […]
- Grand mal
A form of epilepsy characterized by tonic-clonic seizures. involving two phases — the tonic phase in which the body becomes rigid, and clonic phase in which there is uncontrolled jerking. Tonic-clonic seizures may or may not be preceded by an aura, and are often followed by headache, confusion, and sleep. They may last for mere […]
- Grand multipara
“multi-” from “multus”, much + “-para” from “pario”, to bring forth = to bring forth much (in the way of children).