Question 153Protein structure: What determines the primary structure of a cellular protein?the RNA sequence of the ribosome which translates the mRNAO the TRNA sequence of these molecules which translate the protien's geneO the DNA sequence of the protein's geneO the type of solutes surrounding the ribosomes at the time of protein synthesisNot

The proteins are made up of amino acids and chains of amino acids. The proteins are diverse in structure and function. The proteins are those macromolecules in living organisms that are present in most abundant form. Amino acids are the monomers that forms these protein chains. These chains are linked with one another by peptide bonds and hence forms the polypeptide chains.The sequence of amino acids in a polypeptide chain is the primary structure of the proteins. Every protein has a sequence that is determined by their DNA, so it is the DNA sequence of protein genes that determines the primary structure of proteins. Lets take an example of sickle cell anemia to understand primary structure of proteins. It is a inherited disease that affects RBCs. The polypeptide chains that make up hemoglobin in sickle cell anemia has a slight sequence change. The are two protein chains present i.e. alpha and beta. The beta chain of hemoglobin normally contains glutamic acid amino acid at sixth position which is replaced by valine hence changes the structure of normal hemoglobin by producing disc-like cells or crescent shaped that gets stuck inside the blood vessels while passing through it. Hence the correct answer is C