A). The chemical composition and structure of proteins seems quite confusing at first but one it is broken down into levels it is much more understandable. Amino acids are the basic building blocks of proteins and they contain amino, carboxyl and R groups. These R groups that are in the amino acids are what determine the properties of the specific amino acids. For structure, there are 4 levels. The first one being the primary level. These are made up of sequences of amino acids and these amino acids are linked together by peptide bonds. The next level is called secondary. This level is a formation of amino acid chains folded together by a helix formation or a pleated sheet. The bonds between them are hydrogen bonds and they are specifically between carboxyl and amino groups. The third level is called tertiary and is formed by several different bonds such as hydrogen, ionic, disulfide, van der waals, or hydrophobic reactions. These interactions occur between R groups. The fourth level is called quaternary and it is made up of more than one polypeptide. It is made up of the same bonds that the tertiary level is because it is just several tertiary groups together.
B). Three types oh chemical bonds are covalent, hydrogen and ionic. Covalent bonds are bonds that share electrons or link amino acids together. The rode they play in determining protein structure is connecting amino acids to form the correct sequence. Hydrogen bonds are reactions between hydrogen and oxygen or hydrogen and nitrogen and there role in determining protein structure is in the tertiary or quaternary levels. Lastly, ionic bonds are formed by the bonding of charged R groups. These are also found in the tertiary or quaternary levels. C). Dehydration sysnthesis is when you take 2 amino acids and take off the H from the amino and the Oh from the carboxyl and bond them together to make water (H2O). You do this over and over until you get the desired polypeptide chain you want. Hydrolysis is when you out the H2O back into the amino acids so the H goes back into the amino and the OH goes back into the carboxyl to separate the amino acids into two.