2) Proteins are polypeptide chains consisting of monomers called amino acids, which are made up of carbon, hydrogen, oxygen and nitrogen. Amino acids are made up of an amino group, an R group a carboxyl group and an alpha carbon, the different R groups of each individual amino acids determines which amino acid they will form.
Amino acids bond through covalent peptide bonds this occurs via a condensation reaction, which is when one amino acids hydrogen & oxygen (carboxyl group) and another amino acids hydrogen (amino group) react releasing a spare molecule of water (see figure 6) and forming the peptide bond between the carbon and nitrogen, going on to form a polypeptide chain if there are four or more amino acids in the …show more content…
If the polypeptide forms into an alpha helix a hydrogen bonds occurs between the CO (carboxyl group) and NH (amino group) within the polypeptide chain (see figure 9).
If the polypeptide chain form beta pleated sheets (folded chains running parallel to each other) then the hydrogen bonds between the CO (carboxyl group) and NH (amino group) occurs between two separate beta pleated polypeptide chains (see figure 10)
The tertiary structure is the folding of the polypeptide chain after it has determined its secondary structure. Its shape is due to bonding between the side chains (R groups) (see figure 11), these include;
Hydrogen bonds occurs between the R groups when they have an OH molecule and O molecule available to bond.
Ionic bonds occur between two oppositely charged R groups, and they heavily influence the tertiary structure.
Hydrophobic interactions are formed to protect the hydrophobic R groups from water, this has a big impact on the folding of the protein as it will fold to protect the hydrophobic …show more content…
The quaternary structure is not necessary for all proteins. However, a quaternary protein is determined by how many polypeptide chains there are linked and the subsequent arrangement of the individual polypeptide chains, this determines the structure and function of the protein. (See figure