An amino group, a carboxylic acid group, a hydrogen atom and one or more atoms composing a side chain (“R” group) all together make up a monomer called
The correct answer and explanation is:
Correct Answer: Amino Acid
An amino acid is the monomer that contains an amino group, a carboxylic acid group, a hydrogen atom, and a unique side chain known as the R group, all attached to a central carbon atom called the alpha carbon. These four components are what define the structure of an amino acid and differentiate one amino acid from another based on the nature of the R group.
The amino group (-NH₂) is basic in nature, while the carboxylic acid group (-COOH) is acidic. This combination allows amino acids to act as both acids and bases, making them amphoteric. The hydrogen atom and R group also attach to the central carbon, completing the molecule. The R group varies in structure, size, charge, and polarity, giving each amino acid its specific chemical properties.
Amino acids are the building blocks of proteins. During protein synthesis, amino acids link together through peptide bonds in a process known as polymerization. When the carboxylic group of one amino acid reacts with the amino group of another, a water molecule is released, forming a peptide bond. This results in a chain of amino acids called a polypeptide, which folds into a specific three-dimensional structure to form a functional protein.
There are 20 standard amino acids used by cells to build proteins, each with a unique R group. Some R groups are hydrophobic, others are hydrophilic, and some carry charges. This diversity enables proteins to carry out a wide range of biological functions, including enzyme catalysis, cell signaling, transport, and structural support.
Understanding amino acids is essential to fields like biochemistry, molecular biology, and nutrition, as they are central to the structure and function of all living organisms.