Skip to main content
Framed Pictures, Canvas Prints
Posters & Jigsaws since 2004
Home > All Images > 2002 > February > 5 Feb 2002

Images Dated 5th February 2002

Available as Framed Photos, Photos, Wall Art and Gift Items

Choose from 14 pictures in our Images Dated 5th February 2002 collection for your Wall Art or Photo Gift. Popular choices include Framed Photos, Canvas Prints, Posters and Jigsaw Puzzles. All professionally made for quick delivery.

Histidine amino acid Featured 5 Feb 2002 Print

Histidine amino acid

Histidine. Computer model of a molecule of the amino acid histidine (C6. H9. N3.O2). Atoms (solid tubes) are colour-coded: carbon (green), oxygen (red), hydrogen (grey) and nitrogen (blue). It is an essential amino acid (required in the diet), is common in haemoglobin and is essential for growth in infants. It is a precursor to histamine. Here, the zwitterion, an internal salt that forms in the body, is shown. The chemical groups characteristic of an amino acid, the amino (NH2) and the carboxyl (COOH) groups, have reacted together, forming an NH3 group (positively-charged, lower right) and a COO group (negatively-charged, upper right). At lower left is histidine's imidazole ring group