what is a residue?

Question

i'm referring to amino acids. at first i thought the residue was the R group coming off of the amino chain.

Answer 1

A residue, broadly, is anything left behind by a reaction or other process.


In chemistry, a residue refers to a portion of a larger molecule, for example in biochemistry and molecular biology, a residue refers to a specific monomer of a polysaccharide, protein or nucleic acid. For example one might say: "the histidine residue is considered to be basic due to its imidazole ring". Note that a residue is different from a moiety, which, in the above example would consistute the imidazole ring or "the imidazole moiety".

Answer 2

Would this be what you are looking for? :

An amino acid residue is what is left of an amino acid once a molecule of water has been lost (an H+ from the nitrogenous side and an OH- from the carboxylic side) in the formation of a peptide bond, the chemical bond that links the amino acid monomers in a protein chain. Each protein has its own unique amino acid sequence that is known as its primary structure. Just as the letters of the alphabet can be combined in different ways to form an almost endless variety of words, amino acids can be linked together in varying sequences to form a huge variety of proteins. The unique shape of each protein determines its function in the body.

Answer 3

The "R" has nothing to due with "residue"

In protein sequencing, groups are typically chemically removed from the N-terminus one at a time. The residue is the RESIDUAL shortened protein with a new N-terminus. Residue analysis means repeating the analysis on the shortened protein to determine successive amino acids starting from the N-terminus.

Residue has also come to mean each amino acid as it comes off the residue, in sequence.

Answer 4

An amino acid residue is what is left of an amino acid once a molecule of water has been lost in the formation of a peptide bond, the chemical bond that links the amino acid monomers in a protein chain.

(an H+ from the nitrogenous side and an OH- from the carboxylic side)

Answer 5

Residue is a broader concept. It's whatever is left after evaporation, distillation, filtration, decanting, and so on. Mixing two solutions can result in an insoluble compound. This compound precipates and usually settles to the bottom of the container. Take away the liquid, and the residue is what's left.

Even more broadly, residue is whatever's left.