Question

In bacteria, the porins have the unique ability to transport?

1) all hydrophilic molecules.
2) hydrophilic molecules of a particular size.
3) all hydrophobic molecules.
4) hydrophobic molecules of a particular size.
5) any molecule, regardless of properties or size.

Answer 1

Porins in bacteria are channel proteins that selectively transport hydrophilic molecules of a particular size across the outer membrane.

Step-by-step explanation:

In bacteria, porins are a type of protein that facilitate the transport of molecules across the outer membrane. These proteins are specialized channel proteins that allow for the passive transport of certain molecules. Porins generally allow the passage of hydrophilic molecules of a particular size.

The structure of porins consists of a hydrophilic channel that permits these types of molecules to bypass the hydrophobic lipid bilayer of the membrane, which is not permeable to polar or charged molecules. Consequently, porins are selective, allowing molecules above a certain size threshold to pass but blocking others. This is critical for bacteria to control the entry and exit of substances essential for their survival. As a result, the correct answer to the question is that porins have the unique ability to transport hydrophilic molecules of a particular size.