Which of the following best describes the gram-negative cell wall?

• A. Contains a thin peptidoglycan layer and an outer membrane with lipopolysaccharides
• B. Is composed primarily of a thick peptidoglycan layer without an outer membrane
• C. Contains teichoic acids embedded in a thick peptidoglycan layer
• D. Lacks peptidoglycan and consists only of a plasma membrane

Answer: (A)

Verified step by step guidance

1. Recall the basic structural differences between gram-positive and gram-negative bacterial cell walls. Gram-positive bacteria have a thick peptidoglycan layer, while gram-negative bacteria have a thinner peptidoglycan layer.
2. Understand that gram-negative bacteria possess an additional outer membrane outside the thin peptidoglycan layer, which is absent in gram-positive bacteria.
3. Recognize that the outer membrane of gram-negative bacteria contains lipopolysaccharides (LPS), which are important for the bacteria's structural integrity and can act as endotoxins.
4. Note that teichoic acids are components found only in gram-positive bacteria, embedded within their thick peptidoglycan layer, and are not present in gram-negative bacteria.
5. Conclude that the best description of the gram-negative cell wall is that it contains a thin peptidoglycan layer and an outer membrane with lipopolysaccharides.