The level of drug reaches a peak in the bloodstream after one to two hours, and its felt effects last on average about 5 hours. However, Xanax remains in the bloodstream long after its anti-anxiety effects have worn off. Xanaxâs average half-life is 11 hours. This means that it takes an average of 11 hours for the body to eliminate half the Xanax dose. In older or obese people, or those with liver disease, Xanaxâs half-life is longer, as long as 40 hours. It takes several half-lives to eliminate a drug completely. So for most people, there may still be a small fraction of Xanax in your blood two days or more after taking a single pill.
As a result, a modestly sized protein with only 300 amino acids has a molecular weight of 33,000 g/mol, and very large proteins can have molecular weights as high as 1,000,000 g/mol. Proteins are formed by joining the -CO2H end of one amino acid with the -NH2 end of another to form an amide. The -CONH- bond between amino acids is known as a peptide bond because relatively short polymers of amino acids are known as peptides. The same -CONH- bond forms the backbone of both proteins and synthetic fibers such as Nylon.
Proteins vary in structure as well as function. They are constructed from a set of 20 amino acids, which are linked to form polypeptide chains. Polypeptide chains that form distinct three-dimensional shapes constitute a protein. Below is a list of several types of proteins and their functions.