The correct answer is option 2. amino acids.
Amino acids are organic compounds consisting of an amino group \((NH_2)\), a carboxyl group \((COOH)\), a hydrogen atom (H), and a side chain (R group) bonded to a central carbon atom (referred to as the α-carbon). There are 20 different amino acids commonly found in proteins, each with a unique side chain that determines its chemical properties.
When amino acids link together, they form proteins through a process called peptide bond formation. During this process, the carboxyl group of one amino acid reacts with the amino group of another amino acid, releasing a molecule of water \((H_2O)\) and forming a peptide bond \((-CO-NH-)\). This bond joins the amino acids together into a chain called a polypeptide.
The linear sequence of amino acids in a polypeptide chain determines the primary structure of the protein. This primary structure then folds and twists into specific shapes due to interactions between amino acid side chains, leading to the protein's secondary, tertiary, and quaternary structures.
Overall, proteins are large, complex molecules composed of one or more polypeptide chains folded into specific three-dimensional shapes. These shapes are crucial for the proteins' functions, as they determine how the proteins interact with other molecules in biological processes such as enzyme catalysis, cell signaling, and structural support. |
