The permeability of a cell membrane depends on the ability of a molecule to diffuse across that membrane. usually, only molecules that are fat-soluble can permeate a cell membrane because

Amino acids contain the elements carbon, hydrogen, oxygen, nitrogen, and sometimes sulfur. of the 20 amino acids found in humans, 11 are called "nonessential" because they can be manufactured by the body when needed. which elements in these 11 amino acids are commonly obtained from the metabolism of sugar molecules?