Question

The concentration of the appetite-regulating hormone `1.3 times 10^-10` `M` in a fasting person. How many molecules of ghrelin are in 1 L of blood?

Answer 1

Approximately `7.8*10^13` ghrelin molecules are present in a fasting person's blood.

Explanation:

`M` is molarity, units of molarity are `(mol_(solute))/(L_(sol n))`.

Thus there are `1.3*10^-10mol` per liter of blood.

Furthermore, using Avogadro's number, we'll arrive at the solution:

`1.3*10^-10mol* (6.023*10^23 " molecules")/(mol) approx 7.8*10^13" molecules"`

Ghrelin is a protein that functions as a hormone: