What is a characteristic of the right-handed helix in an alpha helix?

The characteristic of the right-handed helix in an alpha helix that is accurate is that each turn contains 3.6 residues. This specific feature is fundamental to the structure of the alpha helix, which is a common secondary structure in proteins.

In an alpha helix, the helical structure forms due to intramolecular hydrogen bonds between the backbone carbonyl oxygen of one amino acid and the backbone amide hydrogen of another amino acid that is four residues down the chain. The effect of this bonding pattern results in a stable helix that turns approximately every 3.6 amino acid residues. This consistent packing allows the helix to maintain its structural integrity and contributes to the overall stability of protein structures.

Furthermore, while it is common for alpha helices to have a specific arrangement of side chains (often hydrophobic ones on the interior in the context of globular proteins), it is not a defining feature of the alpha helix itself. Additionally, the presence of the alpha helix is not limited to fibrous proteins; it can also be found in a variety of proteins, including globular proteins. Therefore, the characteristic that each turn contains 3.6 residues remains the most definitive aspect that defines the right-handed alpha helix structure