What are the acid-soluble and acid-insoluble fractions in the chemical composition of living tissues? Name one chemical compound in each of the above amino fractions.

If we grind a living tissue in tri chloro acetic acid, thick slurry is obtained. If we filter it through a cheese cloth or cotton, we can have a filtrate, the acid soluble fraction and the residue is acid insoluble fraction. Together they represent the entire chemical composition of living tissues or organisms.

• The acid insoluble fraction, has only four types of organic compounds i.e., proteins, nucleic acids, polysaccharides and lipids with the exception of lipids. The macromolecules from cytoplasm and organelles become the acid insoluble fraction.
• The acid soluble pool represents roughly the cytoplasmic composition.