Which of the following is NOT a typical characteristic of most bacterial plasma membranes?

• A. Contains integral and peripheral proteins
• B. Functions as a selective barrier for transport
• C. Presence of sterols such as cholesterol
• D. Composed of a phospholipid bilayer

Answer: (C)

Verified step by step guidance

1. Step 1: Understand the typical composition of bacterial plasma membranes. Most bacterial membranes are composed of a phospholipid bilayer with embedded proteins, including both integral and peripheral proteins.
2. Step 2: Recognize the functional role of the bacterial plasma membrane. It acts as a selective barrier, controlling the transport of substances into and out of the cell.
3. Step 3: Identify the presence or absence of sterols such as cholesterol in bacterial membranes. Unlike eukaryotic membranes, most bacterial plasma membranes do not contain sterols like cholesterol, with some exceptions in certain bacteria.
4. Step 4: Compare each option against these known characteristics: integral and peripheral proteins are typical, selective transport is a key function, and the phospholipid bilayer is the structural basis.
5. Step 5: Conclude that the presence of sterols such as cholesterol is NOT a typical characteristic of most bacterial plasma membranes, making it the correct answer to the question.