Question

Would these two formed as a disaccharide be polar or non polar Why?

Valine Threonine 'c-c-N. HOCH HN--C нес сн, н Сн он но сн,

Answer 1

Valine is a nonpolar aminoacid. Nonpolar means molecule has no separation of charge , so no positive or negative poles are formed. In other words the electrical charges of nonpolar molecule are evenly distributed across the molecules.

Examples of nonpolar aminoacids are alanine, isoleucine, leucine, phenylalanine, proline, glycine,valine, methionine, tyrosine, tryptophan. The number of alkyl groups also influnces the polarity. The more alkyl group present , the more non polar aminoacid will be. This effect makes valine more nonpolar than alanine. Leucine is more nonpolar than valine.

Threonine is a polar aminoacid. Six amino acids have side chain that are polar but not charged. These are serine, threonine, cysteine, asparagine, glutamine, and tyrosine. These amino acids are found at the surface of protein.

Theronine are polar since both carry a hydroxyl group, asparagine, and glutamine carry a polar amide group.

The properties of amino acids are due to properties of the side chain or R group. All polar aminoacid have either n OH or NH2 group, and can there for make hydrogen bonds with other suitable groups.