Nursing HAP201 Lecture Notes - Lecture 1: Hemoglobin, Covalent Bond, Ammonia
Document Summary
Proteins are the most abundant and functionally diverse molecules in living systems. Virtually every life process depends on this class of molecules. For example, enzymes and polypeptide hormones direct and regulate metabolism in the body, whereas contractile proteins in muscle permit movement. In bone, the protein collagen forms a framework for the deposition of calcium phosphate crystals, acting like the steel cables in reinforced concrete. In the bloodstream, proteins, such as hemoglobin and plasma albumin, shuttle molecules essential to life, whereas immuno globulins fight infectious bacteria and viruses. In short, proteins display an incredible diversity of functions, yet all share the common structural feature of being linear polymers of amino acids. This chapter describes the properties of amino acids. Although more than 300 different amino acids have been described in nature, only 20 are commonly found as constituents of mammalian proteins. [note: these are the only amino acids that are coded for by dna, the genetic material in the cell.
