Question

select all that apply
which four of the following are functions of lipopolysaccharide?

maintains cell shape as a structural support

aids in genome replication

provides energy for flagellar rotation

protects from environmental toxins (and immunological factors)

stabilizes the outer membrane

makes a permeability barrier

contributes to the negative charge of the cell

Explanation:

Lipopolysaccharide (LPS) is part of the outer membrane of Gram - negative bacteria.

1. Protects from environmental toxins (and immunological factors): LPS acts as a barrier, preventing harmful substances like toxins and components of the immune system from entering the cell easily.
2. Stabilizes the outer membrane: It is an important structural component that helps maintain the integrity and stability of the outer membrane.
3. Makes a permeability barrier: The outer membrane with LPS restricts the passage of many molecules, acting as a permeability barrier.
4. Contributes to the negative charge of the cell: The polysaccharide part of LPS has negatively charged groups, which contribute to the overall negative charge of the bacterial cell surface.

• "Maintains cell shape as a structural support" is a function of peptidoglycan, not LPS.
• "Aids in genome replication" is not a function of LPS; genome replication is carried out by enzymes and other cellular machinery related to DNA.
• "Provides energy for flagellar rotation" is done by the proton - motive force, not LPS.

Answer:

• Protects from environmental toxins (and immunological factors)
• Stabilizes the outer membrane
• Makes a permeability barrier
• Contributes to the negative charge of the cell