Question

Name the four levels of protein structure, describe the structural characteristics at each level, and name the types of bonds or other forces involved at each level.

Answer 1

the four types of protein structure are determined by the degree of complexity in the polypeptide chain.

1.primary structure: the linear order of amino acids linked together to form a protein. the amino acids are bing together by means of covalent peptide bonds.

2.secondary structure: it refers to the folding of a polypeptide chain that gives the protein a 3D shaped structure. there are two types of secondary structure of proteins and they are alpha helix structure which resembles a coiled or folded spring and is secured by hydrogen bonding in polypeptide chain and the other one is beta pleated sheet that resembles the pleated shape and is held together by hydrogen bonding between polypeptide units of the folded chain.

3.teritiary structure: it resembles the comprehensive 3D structure of the polypeptide chain of a protein.there are three types of bonds that hold the protein in its teritary structure
1.hydrogen bonding: binds the polypeptide chain and the amino acids and helps to stabilize the protein structure.
2. ionic bonding: it occurs between the positively and negatively charged amino groups.
3.hydrophobic interactions: they hepls in formation of folding shape of the protein.

4.quaternary structure: it refers to the structure of a protein which is formed by the interactions between multiple polypeptide chains. a subunit is refered as the each polypeptide chain. proteins with the quaternary structue may consists of more than one subunit of the same kind.