Final answer:
The R groups of amino acids determine the tertiary structure of proteins through various interactions such as hydrophobic and ionic interactions, and disulfide bond formation. Hydrophobic R groups tend to be located in the protein's interior, while hydrophilic groups are on the exterior, influencing protein folding.
Step-by-step explanation:
How R Groups Influence Protein Folding
Proteins have a complex three-dimensional tertiary structure that is crucial for their function. The R groups, or side chains, of amino acids play a pivotal role in determining this structure. The properties of the R groups—such as whether they are hydrophilic or hydrophobic, acidic, basic, polar, or nonpolar—create various interactions that lead to the protein folding in a specific manner. If R groups have like charges, they repel each other, while those with unlike charges may form ionic bonds. During protein folding, hydrophobic R groups typically aggregate towards the interior of the protein, avoiding water, which is a key component of hydrophobic interactions. Conversely, hydrophilic R groups are oriented toward the aqueous environment. Additionally, cysteine side chains can form disulfide linkages, the only covalent bonds created during protein folding. These diverse interactions, including hydrogen bonding and van der Waals forces, establish the final three-dimensional shape of the protein.