Leucine

## General Information (more on wikipidia)

 Molecular Weight (g/mol) Density (g/L) Radius (m) Reference Species Leucine 131.18 D R [1]

Leucine is an α-amino acid with the chemical formula HO2CCH(NH2)CH2CH(CH3)2. Its three letter code is leu, its one letter code is L, and its codons are UUA, UUG, CUU, CUC, CUA, and CUG. It is an essential amino acid, which means that humans cannot synthesise it. With a hydrocarbon side chain, leucine is classified as a hydrophobic amino acid. It is an isomer of isoleucine.

As an essential amino acid, leucine is not synthesized in animals, hence it must be ingested, usually as a component of proteins. It is synthesized in plants and microorganisms via several steps starting from pyruvic acid. The initial part of the pathway also leads to valine. The intermediate α-ketovalerate is converted to α-isopropylmalate and then β-isopropylmalate, which is dehydrogenated to α-ketoisocaproate, which in the final step undergoes reductive amination.

## Diffusion of in water:

• Alone at 25 degrees: $D = 730 \ \mu m^{2} s^{-1}$ [1]

## Diffusion of in PBS:

• $D = \ \mu m^{2} s^{-1}$

## Diffusion of in cellular matrix:

• $D = \ \mu m^{2} s^{-1}$
Bibliography
1. Longsworth, L. G. 1955. Diffusion in liquids and the Stokes-Einstein relation, p. 225-247. In T. Shedlovsky (ed.), Electrochemistry in biology and medicine. John Wiley & Sons, Inc., New York, N.Y.