Which of the following components are found in the cell walls of gram-positive bacteria but not gram-negative bacteria?

Teichoic acids are components specifically found in the cell walls of gram-positive bacteria. These polymers, which can be either wall teichoic acids or lipoteichoic acids, play several essential roles in the bacterial cell wall structure and function. They contribute to the rigidity and structural integrity of the cell wall, help in maintaining the shape of the bacterium, and can be involved in processes like cell division and the binding of cations.

In contrast, gram-negative bacteria have a different cell wall structure, characterized by a thin peptidoglycan layer sandwiched between an inner cytoplasmic membrane and an outer membrane. The presence of an outer membrane in gram-negative bacteria is a key distinguishing feature, as it contains lipopolysaccharide—an important component of their cell envelope that contributes to virulence and immune evasion.

Therefore, teichoic acids are present in gram-positive bacteria but are absent in gram-negative bacteria, making this option the correct choice in distinguishing between these two groups of bacteria.