1. Nucleic Acids : RNA and DNA
Nucleoproteins – are conjugated proteins, the
prosthetic group of which are nucleic acids
Nucleic acids – are macromolecules found abundant
in tissues possessing closed packed cells with big
nuclei like thymus, liver, spleen, kidney, and
pancreas
- also found in bacteria, bacteriophages,
chromosomes and constitute the whole make-up
of the simple filterable viruses
The protein components of the nucleoproteins are
simple proteins, albumins, histones and protamins
Properties of Nucleoproteins
1. acidic, soluble in alkalis and hot water forming
salts
2. insoluble in alcohol
3. slightly soluble in cold water
4. precipitated by acetic acid but are redissolved by
dilute HCL

2. Importance of Nucleoproteins
1. closely associated with the chromosomes of the
cells
2. act as co-factors to the enzymes – catalytic
activities
3. play a role in the energy transfer in living
organisms
Types of Nucleic acids
1. RNA – less strictly org. than DNA; exists as a
single strand
Types of RNA
a. messenger RNA (mRNA) – 3% - contains
genetic code transcribed from DNA; also
called template RNA or information RNA
b. transfer RNA (tRNA)- 10-20% of cellular
RNA; “soluble RNA”
c. ribosomal RNA (rRNA) -80% - provides the
working area for protein synthesis
d. viral RNA (vRNA) – forms the chemical
nature of viruses; ex. RNA viruses in
poliomyelitis, common colds, influenza
2. DNA – similar to RNA , acid, alkali, heat, and
low ionic strength can cause denaturation of
DNA

3. Melting temperature – temperature at which 50%
of the molecule is denaturated
Renaturation (annealing) of DNA – if the
temperature of the melted DNA is lowered or
below the melting temperature, so double bond is
reformed
RNA DNA
1. functions Protein Storage and
synthesis transmission of genetic
material
2. sugar d- ribose d- deoxyribose
composition
3. Pyrimidine uracil thymine
base
composition
4. structure Single strand Double helix
5. source Isolated Tissues with large
from yeast nuclei- thymus,liver,
spleen,kidney,pancreas
Feulgen test – differentiates the DNA from RNA

4. Properties of purines and pyrimidines
1. they have limited solubilities in water
2. they exist in lactam-lactim form (keto-enol)
tautomeric forms
3. absorb UV light- maximum absorption occurring
around 260nm. This property is frequently used
for the detection and quantitative determination
of nucleic acid
Nucleoproteins when treated with weak acid, alkali
and enzymes will undergo degradation into various
products.
Nucleoproteins
Simple proteins Nucleic acids
Nuclease
Nucleotides
Nucleotidase
Phosphates Nucleosides
Nucleosidase
Sugar N2 Base
d- ribose pyrimidine
d-deoxyribose purine
adenine
guanine