Which of the Following Statements Regarding Hydrogen Bonding in Secondary

Question

Which of the following statements regarding hydrogen bonding in secondary structures is true?
A) Both α-helices and β-sheets only use intrachain hydrogen bonds.
B) Both α-helices and β-sheets only use interchain hydrogen bonds.
C) α-helices only use intrachain hydrogen bonds and β-sheets can use either intrachain or interchain hydrogen bonds.
D) α-helices can use either intrachain or interchain hydrogen bonds and β-sheets only use interchain hydrogen bonds.

Accepted Answer

α-helices only use intrachain hydrogen bonds, while β-sheets can use either intrachain or interchain hydrogen bonds. This is because α-helices are formed by a single polypeptide chain that is coiled in a helical shape, allowing for intrachain hydrogen bonding between the carbonyl and amino groups within the polypeptide backbone. In contrast, β-sheets are formed by multiple polypeptide chains or by a single polypeptide chain folded back on itself, allowing for both intrachain and interchain hydrogen bonding between adjacent strands.