Ion channels are formed by a particular kind of membrane protein that allows the passage of a specific ion under certain conditions.This type of protein is most likely a(n)
A) peripheral protein with additional hydrophobic domains.
B) integral protein with a transmembrane domain.
C) phospholipid with hydrophilic domains.
D) enzyme with an asymmetrical arrangement on either side of the plasma membrane.
E) membrane protein that is able to move freely within the phospholipid bilayer.

Question

Quizplus · Accepted Answer

Ion channels are transmembrane proteins that span the lipid bilayer and have hydrophilic pores that allow ions to pass through. Peripheral proteins do not extend into the hydrophobic interior of the membrane and are not able to form pores. Phospholipids are components of the membrane, but they cannot act as channels. Enzymes may be embedded in the plasma membrane, but they do not form pores for ion passage. While some membrane proteins are able to move within the phospholipid bilayer, this is not a requirement for ion channels.

Ion Channels Are Formed by a Particular Kind of Membrane