Question

Bacterial porins transport

A) any hydrophilic molecule regardless of size.
B) hydrophilic molecules smaller than 600 Da.
C) any hydrophobic molecule regardless of size.
D) hydrophobic molecules larger than 600 Da.
E) any molecule regardless of properties or size.

Answer 1

Bacterial porins are channel proteins that selectively transport hydrophilic molecules smaller than 600 Da across the cell membrane.

Step-by-step explanation:

The student's question pertains to the specificity of bacterial porins in transporting molecules across the cell membrane. Bacterial porins are a type of protein that create channels through the bacterial cell membrane. These channel proteins are selective and generally allow the passage of certain hydrophilic (water-loving) molecules. According to the information provided, porins are selective not only based on the polarity of the molecules but also on their size. The correct answer to the student's question is that bacterial porins transport hydrophilic molecules smaller than 600 Da. This is because the interior of the plasma membrane is hydrophobic (water-hating), and thus polar molecules cannot pass through it without assistance, and their size must be small enough to fit through the pores of the porin protein channels.