Part A: Describe protein structure, level of structure and geometry. Include in a description what the structure means and how it affects the analysis. Levels of Protein Structure There are four levels of protein structure that are separated from each other by the degree of complication in the polypeptide chain. A protein molecule can consist of one or more types of protein structure. 1-) The primary structure is the sequence of a chain of amino acids. Proteins are made up of 20 different amino acids. Amino acids are composed of a carbon (α carbon) that bonds to the hydrogen atom (H), a carboxyl group (-COOH), an amino group (-NH2) and a variable group, or R group. The primary structure is determined during translation. There are two tools used to determine primary structure; Edman degradation and mass spectrometry. The primary structure controls the secondary, tertiary and quaternary structures. It is also used to determine molecular mass and isoelectric point. 2-) Secondary structure describes the coiling or folding of a protein due to the unique hydrogen bonding between its amide structure and carbonyl groups. These secondary structures are held together by hydrogen bonds. There are three types of secondary structures in proteins. a-) The alpha helix (α-helix) is a coiled arrangement around the polypeptide backbone. The inner part of the coil is formed by the peptide backbone while the side chains extend outward from the coil. Hydrogen bonds between NH of one amino acid and C=O on the fourth amino acid stabilize the helix. b-) Beta fold beta sheet involves H bonding between backbone residues in adjacent chains. The orientation of a beta pleated sheet can occur in two types. The strands can be parallel... to the center of the paper... From) to grw175 (28 kDa) proving the above observation to be true. b-) Molecular mass of the gene product graphic was then generated4.) I selected the MW lane peaks to use in the molwt.macros program5.) Based on the calculations generated using the molwt macros program I was then able to select the peaks of interest and calculate a numerical value for them6.) ImageJ indicated a peak of 56kda for positive grw19 and a value of 28kda in positive grw175.7.) Using the numerical values ​​I was able to subtract the estimated size of grw175 of 28kda from the size of what is believed to be the fusion protein grw19 56kda8.) Grw175 = 28kda – fusion protein 56kda to give you a value of = 28kda