<h2><u>Full Question:</u></h2>
Your body contains tens of thousands of different proteins, each with a specific structure and function. The unique shape of each of these diverse proteins is based on several superimposed levels of structure. Which of the following statements is true?
a.The primary structure of a protein is the order of nucleic acids in a polypeptide.
b.The 20 amino acids found in proteins differ in the composition of their R groups, which may be either polar or charged.
c.Tertiary structure is the overall shape of a polypeptide, which may be stabilized by hydrophobic interactions, hydrogen bonds, ionic bonds, and covalent bonds
d.Quaternary structure is only found in proteins that have four identical polypeptide subunits.
e.Secondary structures, which include the alpha helix or beta pleated sheet, are held together by interactions between R groups.
<h2><u>Answer:</u></h2>
The 20 amino acids found in proteins differ in the composition of their R groups, which may be either polar or charged.
Option B.
<h3><u>Explanation:</u></h3>
The proteins are one of the most abundant biomolecule of the biosphere. The proteins are formed by the polymerization of the amino acids which are actually 20 in type. The amino acids are basically of the same framework - having an alpha carbon with which are attached a carboxy group, amino group, a hydrogen and a variable group on which the actual property of amino acid depends. There are 20 different variable groups and so, there are 20 different amino acids.
Among them, 8 are essential amino acids, not synthesized in body and rest 12 are non essential amino acids, synthesized in body. These variable groups are either alkyl group, or aromatic group. They may be polar or non polar.
