An amino acid mixture consisting of alanine, phenylalanine, and lysine is to be separated by normal phase HPLC. The stationary phase is polar and the mobile phase is a nonpolar solvent. The first amino acid to be eluted will be . The last amino acid to be eluted will be:

Phenylanine; Lysine

An amino acid mixture consisting of alanine, phenylalanine, and lysine is to be separated by normal phase HPLC. The stationary phase is polar and the mobile phase is a nonpolar solvent. The first amino acid to be eluted will be Phenylanine. The last amino acid to be eluted will be: Lysine

Explanation:

In normal phase HPLC (High performance liquid chromatography), the polar stationary phase would retain the less nonpolar amino acids (alanine and lysine) while the nonpolar mobile phase would permit the quick elution of the aromatic amino acid, phenylanine. Thus, phenylanine is first eluted.

This is then followed by the elution of the amino acid with nonpolar side chain, alanine. Thus, alanine is the second to be eluted.

Lastly, the positively charged amino acid, lysine will be released by the stationary phase. Thus, lysine is the last to be eluted

in 1972 the fluid—mosaic membrane model of membrane structure was proposed based on thermodynamic principals of organization of membrane lipids and proteins and available evidence of asymmetry and lateral mobility within the membrane matrix [s. j. singer and g. l. nicolson, science 175 (1972) 720–731].

i think the miocene epoch spans the time from 23 million to 12 million years ago.