Final answer:
Lipopolysaccharide (LPS) is composed of lipid A, a core oligosaccharide, and O-antigen, each requiring a separate biosynthetic pathway. Therefore, the synthesis of LPS entails three distinct pathways tailored for the production of its different components.
Step-by-step explanation:
The biosynthesis of lipopolysaccharide (LPS) is a complex process that involves multiple biosynthetic pathways. LPS is a major component of the outer membrane of gram-negative bacteria, composed of lipid A, a core oligosaccharide, and the O-antigen. The synthesis of these three parts requires different enzymatic processes. Lipid A is a glycolipid that anchors LPS to the bacterial membrane and is considered the endotoxic component responsible for inducing inflammation and fever.
The core oligosaccharide links to lipid A and provides structural stability to LPS. The O-antigen, which varies among bacterial species and strains, extends outwards from the core oligosaccharide and is critical for immune system recognition and determining the serotype of the bacteria. Each part has a distinct biosynthetic pathway, involving fatty acid synthesis, glycosidic linkages, and possibly the involvement of other lipid macromolecules.
Therefore, the correct answer to the question 'Lipopolysaccharide is comprised of three moieties (lipid A, core oligosaccharide, and O-antigen), which require how many biosynthetic pathways?' is three. These pathways are distinct and tailored for the production of each component of the LPS molecule.