If the molecular weight of a protein is given as 90,000 are the units g/mol or simply g? I have seen mixed answers to this question.
It will be 90,000 g/mol since 1 mol will have a mass of 90,000. But many simply drop the the mol and say the molecular weight is 90,000 g and we all understand it is the mass of mol (hence the term "molecular weight" which has been replace in recent years as "molar mass."
To determine the units for the molecular weight of a protein, it is important to understand the concept of molar mass. Molar mass refers to the mass of one mole of a substance and is commonly expressed in grams per mole (g/mol).
In the case of a protein with a given molecular weight of 90,000, it is safe to assume that the units are g/mol. This means that for every mole of the protein, its mass is 90,000 grams.
However, it is worth mentioning that some sources or contexts may omit the "mol" when referring to molecular weight. This can lead to confusion, as it can be interpreted as though the mass is in grams alone, rather than grams per mole.
To avoid any ambiguity, it is recommended to use the correct units (g/mol) when discussing molecular weight or molar mass, as it provides a more precise and universally understood representation.