Which of the following best explains why bacteria lack ether-linked cell membranes?

• A. Bacteria possess enzymes that specifically synthesize ester-linked phospholipids rather than ether-linked lipids.
• B. The presence of ether-linked membranes would make bacteria susceptible to viral infection.
• C. Bacteria lack cell membranes entirely and therefore do not require ether linkages.
• D. Ether-linked membranes are required for aerobic respiration, which bacteria do not perform.

Answer: (A)

Verified step by step guidance

1. Understand the difference between ester-linked and ether-linked phospholipids in cell membranes. Bacteria typically have ester-linked phospholipids, while archaea have ether-linked phospholipids.
2. Recognize that the type of linkage in membrane lipids is determined by the enzymes present in the organism. Bacteria have enzymes that synthesize ester bonds, not ether bonds.
3. Consider the biological implications: the presence or absence of certain enzymes dictates the membrane composition, rather than susceptibility to viral infection or metabolic processes like aerobic respiration.
4. Recall that bacteria do have cell membranes, so the option stating they lack membranes entirely is incorrect.
5. Conclude that the best explanation is that bacteria possess enzymes that specifically synthesize ester-linked phospholipids rather than ether-linked lipids.