32 Mycobacterium tuberculosis is very difficult to stain bec

32) Mycobacterium tuberculosis is very difficult to stain because of the

A) presence of ribosomes in the cytoplasm.

B) location of the DNA within the cell.

C) large amounts of a waxy lipid present in its cell wall.

D) lack of a cell wall.

Solution

C. Large amount of waxy lipid present in its cell wall.

The lipid rich cell wall make them resistant to chemicals.

They cannot be stained by Gram staining because of high lipid content.

Acid fast staining is used to stain mycobacteria. Bacteria are treated with a red dye (fuchsin) and steamed. This drives the stain into the cell and because of the lipid, they become difficult to destain.Once stained they resist decolorization with 3% hydrochloric acid and 95% alcohol (\"acid fast\").

the cell wall of Mycobacterium spp. consists of peptidoglycan plus a number of unusual glycolipids including arabinogalactan, lipoarabinomannan, and mycolic acid. Lipids make up more than 10% of the total weight of the cell of mycobacteria.