At sea level, a normal blood oxygen level (saturation) is usually 96 - 97%. Although there are no generally accepted classifications for severity of oxygen desaturation, reductions to not less than 90% usually are considered mild.Dips into the 80 - 89% range can be considered moderate, and those below 80% are severe.t sea level, a normal blood oxygen level (saturation) is usually 96 - 97%. Although there are no generally accepted classifications for severity of oxygen desaturation, reductions to not less than 90% usually are considered mild.
Because all amino acids contain amine and carboxylic acid functional groups, they share amphiprotic properties. Below pH 2.2, the predominant form will have a neutral carboxylic acid group and a positive Î±-ammonium ion (net charge +1), and above pH 9.4, a negative carboxylate and neutral Î±-amino group (net charge â1).
Amino Acids. Proteins are polymers of amino acids joined together by peptide bonds. There are 20 different amino acids that make up essentially all proteins on earth. Each of these amino acids has a fundamental design composed of a central carbon (also called the alpha carbon) bonded to: 1  a hydrogen. 2  a carboxyl group. 3  an amino group. 4  a unique side chain or R-group.