Page 10 - Lesson Notes - Biomolecules 1

Note:
* Nucleic acids (DNA and RNA) are composed of only nucleotides, both DNA and
RNA acts as a genetic material.
* Uracil is found only in RNA in place of thymine.
* Ribose molecule differs from deoxyribose molecule in having a -OH group instead
of H at carbon 2.
* Heterocyclic compounds have more than one kind of atoms.
Functions
Both primary and secondary metabolities serves the followingjunctions
(i) Many of them are useful in human welfare, e.g., Rubber, drugs, spices, scents,
pigments.
(ii) Some have ecological importance.

Topic 2 Biomacromolecules

Biomacromolecules are large in size, higher molecular weight molecules 10,000
daltons (Da) and above (except lipids).
These are generally formed by linking a number of micromolecules commonly
known as monomers.
All these compounds are found in the acid insoluble pool. These are of four major
types, i.e., proteins, polysaccharides, nucleic acids and lipids.
Except lipids all other macromolecules are formed by polymerisation (condensation)
of monomeric subunits.
The molecules which are found in living organisms are divided into two main types
(i) Biomicromolecules These are molecules which have their molecular weight less
than 10,000 Da.
Biomicromolecules has already been described in detail in topic 1 of the chapter. .
(ii) Biomacromolecules These are molecules which have their molecular weight,
10,000 Da and above.
All these macromolecules are actually polymers of their biomicromolecules.
For example, Polysaccharides are polymers of monosaccharides, proteins are
polymers of amino acids and nucleic acids are polymers of nucleotides.