Question

Are bacterial walls simpler or more complex?

If you remove the cell wall of a bacterium, the cell must be kept in isotonic solution (same concentration of solutes as the cytoplasm). Why is that?

What does this tell you about the main function of the cell wall in bacteria? What are the other functions?

How is the outer membrane of gram-negative bacteria similar to the plasma membrane and how different?

Define/describe the relevance of lipopolysaccharide and porins What is the relevance of bacterial cell walls in the treatment of bacterial infections?

Answer 1

Bacterial cell walls are complex structure and gram negative bacteria's cell wall is more complex than cell wall of gram positive bacteria. Cell wall of gram positive bacteria are thick and formed of peptidoglycan and teichoic acid . Cell wall of gram negative bacteria is complex as peptidoglycan layer of is thin and further supprted by glycolipids also called lipopolysaccharide .

If cell is kept in hypotonic solution instead of isotonic solution water enters inside cell and bacteria will die due to cell swelling. Again if kept in hypertonic solution water will leave the cell and bacteria will die due to dehydration. From this point of view main function of a cell wall is to balance osmotic pressure.

Other functions include maintaining cell shape, act as coarse filter ,provides tensile strength, protection from mechanical damage, prevents from infection .