Page 1 - Lesson Notes - Biomolecules 1

A cell is composed of variety of molecules (like carbon, hydrogen, oxygen) which
perform various functions.
Other than these basic elements, some metals and non-metals are also present as
cellular materials, thence, all these materials combines in different ways in order to
form various biomolecules, which are found in cells of organisms.
These molecules are not living, but perform various living functions. Thus,
biomolecules are the organic substances (e.g., Carbohydrates, proteins, lipids, etc.)
that play a major role in the structure and function of the living organism.
Water is also an important and most abundant chemical compound present in the
body of living organism.

Topic 1 Analysis of Basic

Units of Biomolecules
Chemical Analysis & Cyanic Compounds
To analyse the chemical composition of any organic compound in a living organism,
the chemical analysis of living tissue is done. As organic compounds play a major
role, it is essential to have knowledge of their molecular formula and structure.
This can be easily predicted out by performing following steps
(i) Weight of a living tissue (like a piece of a liver, fruit, vegetable or any other body
tissue) is taken.
(ii) The tissue is then grinded in trichloroacetic acid (Cl 3CCOOH) with the help of
mortar and pestle.
(iii) The thick slurry obtained is then filtered through a cheese-cloth or cotton.
This will generate two fractions of solution
(a) Filtrate or the acid-soluble fraction.
(b) Retentate or the acid-insoluble fraction.
(iv) The extract can then be subjected to numerous separation techniques, in order
to obtain the desirable compound from all other components.
By successfully performing all the above steps, we can get an idea of the molecular
formula and the probable structure of the compound.
(v) All the carbon compounds that we get from living tissues can be called
biomolecules.
Ash Analysis for Inorganic Compound and Elements
After the analysis of chemical composition of an organic compound in a tissue, it is
necessary to do the analysis of inorganic elements and compounds. It can be done
easily by performing a destructive experiment that separate inorganic compounds
from organic compounds in the form of ash (contains inorganic compounds and
elements).
Ash is the remaining part of apy living tissue which remains back after burning of all
organic compounds.
Ash analysis is done in order to analyse the chemical composition of different
inorganic compounds and elements. It is done in the following way
(i) For analysis, a small amount of a living tissue is taken, which is oven dried till all
the water evaporates.
(ii) This gives the dry weight.
(iii) After that tissue is burnt completely which results in the formation of ash.