Final answer:
Sodium dodecylsulfate (SDS) is used to solubilize membrane proteins because it is amphipathic. SDS has both a hydrophobic hydrocarbon tail and a hydrophilic sulfate group, allowing it to interact with and disrupt lipid bilayers as well as unfold proteins, conferring a negative charge for analytical procedures like SDS-PAGE.
Step-by-step explanation:
The detergent sodium dodecylsulfate (SDS) is used to solubilize membrane proteins primarily because it is amphipathic. An amphipathic molecule contains both a nonpolar hydrocarbon end, which is hydrophobic, and an ionic end, which is hydrophilic, allowing it to interact with both lipids and water.
SDS is a type of anionic detergent with a hydrophobic hydrocarbon tail (typically 12 carbon atoms long in the case of SDS) and a polar sulfate group, making it ideal for disrupting the lipid bilayers of membranes as well as denaturing proteins. By binding to protein chains, it confers a negative charge to each polypeptide chain and also disrupts the non-covalent bonds that maintain the protein's structure, effectively unfolding the proteins and allowing them to be solubilized in water.
In laboratory contexts such as SDS-PAGE, SDS provides a uniform negative charge to proteins, which overrides any intrinsic charges, enabling their separation based on size rather than charge during electrophoresis within a polyacrylamide gel. Therefore, among the options provided, the correct characterization of SDS related to its protein solubilization ability is amphipathic.