A Proposed Structure of a Bacterial Membrane Protein Shows That

question 51

Multiple Choice

A proposed structure of a bacterial membrane protein shows that the distance between successive amino acids in a region crossing the membrane is 3.4 Å.Recall that a typical lipid bilayer is approximately 40 Å across.Which of the following is the most likely description of the protein?

• A) The transmembrane region of the protein resembles the transmembrane region of the Ca²⁺-ATPase transporter protein.
• B) The primary sequence of the transmembrane region of the protein is composed of approximately nine amino acids.
• C) The protein contains a selectivity channel.
• D) The protein resembles a porin.

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Definitions:

D-Talose

A type of sugar, specifically a monosaccharide, that is part of the aldohexose family and is known for its optical activity.

Methyl β-D-Talopyranoside

A methyl glycoside formed from the β-D-Talopyranose form of talose, demonstrating how sugars can be chemically modified to glycosides.

Aglycone

The non-sugar portion of a glycoside molecule, which becomes free when the glycosidic bond is hydrolyzed.

Anomeric Carbon

The carbon atom in a cyclic saccharide that is connected to two oxygen atoms, one in an ether linkage and the other in a hydroxyl group, and its configuration determines the alpha or beta form of the saccharide.