Proteins are made from what monomer subunits?
The correct answer and explanation is:
Proteins are made from monomer subunits called amino acids. These amino acids are linked together through peptide bonds to form polypeptides, which then fold into functional protein structures.
Amino acids are organic compounds that contain both an amino group (–NH2) and a carboxyl group (–COOH). There are 20 standard amino acids, each with a unique side chain or R-group. These side chains vary in size, charge, polarity, and other characteristics, which influence how the amino acids interact with each other and fold into a specific three-dimensional structure. The sequence of amino acids in a protein, determined by the genetic code, is crucial for the protein’s function. Even a single change in the amino acid sequence can alter the protein’s function, which is why mutations can lead to diseases.
When amino acids are linked together in a chain, a peptide bond forms between the carboxyl group of one amino acid and the amino group of the next. This bond forms through a condensation reaction, where a water molecule is released. As more amino acids are added, the polypeptide chain grows. The final protein structure is determined by both the sequence of amino acids and how the polypeptide folds, which is influenced by interactions such as hydrogen bonds, ionic bonds, and hydrophobic interactions.
Proteins can have up to four levels of structure: primary, secondary, tertiary, and quaternary. The primary structure is the linear sequence of amino acids. The secondary structure refers to local folding patterns, like alpha helices or beta sheets, formed through hydrogen bonding. The tertiary structure is the overall three-dimensional shape of the protein, while the quaternary structure involves the assembly of multiple polypeptide chains into a functional protein complex.
In summary, proteins are made from amino acids, which are linked together to form polypeptides that fold into functional proteins.