Nucleic acids are the primary information-carrying molecules in cells and play an especially important role in directing protein synthesis. The two main classes are deoxyribonucleic acid (DNA) and ribonucleic acid (RNA). DNA and RNA are both polynucleotides composed of nucleotides with a sugar, phosphate group, and one of five nitrogenous bases. The bases found in DNA are adenine, cytosine, guanine, and thymine, while RNA contains adenine, cytosine, guanine, and uracil instead of thymine. Watson and Crick discovered that DNA exists as a double-stranded helical structure, with the bases on the inside pairing in

1. By
Dr. G. Balakrishnan
Assistant Professor
Department of Chemistry
Vivekananda College
Madurai, Tamil Nadu
4/20/2020
Nucleic acids
BIOMOLECULES-(II B.Sc)
Subject Code: 07SB4A

2. Nucleic acids
 Nucleic acids are naturally occurring chemical
compounds that serve as the primary information-
carrying molecules in cells.
 They play an especially important role in directing
protein synthesis.
 The two main classes of nucleic acids are
deoxyribonucleic acid (DNA) and ribonucleic acid (RNA).

3. Basic structure of Nucelic acid
Nucleic acids are polynucleotides.
Each nucleotide consists of sugar, which is in turn attached to a phosphate
group.
Each nucleic acid contains four of five possible nitrogen-containing bases:
adenine (A), guanine (G), cytosine (C), thymine (T), and uracil (U).
All nucleic acids contain the bases A, C, and G; T, however, is found only in
DNA, while U is found in RNA.
These nucleoside linkages are called phosphodiester bonds and are the
same in RNA and DNA.
https://courses.lumenlearning.com/wm-nmbiology1/chapter/reading-structure-of-nucleic-acids/

4. Nucleosides Vs Nucleotides
https://www.differencebetween.com/difference-between-nucleoside-and-nucleotide-reverse-transcriptase-inhibitors/

5. Double helical structure of DNA
(Watson - Crick Model)

6.  Watson and Crick shared the Nobel Prize in 1962 for
their discovery.
 Deoxyribonucleic Acid (DNA) is a double-stranded,
helical molecule. It consists of two sugar-phosphate
backbones on the outside, held together by hydrogen
bonds between pairs of nitrogenous bases on the inside.
 The bases are of four types (A, C, G, & T): pairing
always occurs between A & T, and C & G.
 James Watson (1928 - ) and Francis Crick (1916 -
2004) realized that these pairing rules meant that either
strand contained all the information necessary to make a
new copy of the entire molecule, and that
the aperiodic order of bases might provide a "genetic
code".

7. various forms of DNA
Three major forms of DNA are double stranded and connected by
interactions between complementary base pairs. These are terms A-form,
B-form,and Z-form DNA.

8. RNA (Ribonucleic acid )
 Ribonucleic acid is a polymeric molecule
essential in various biological roles in
coding, decoding, regulation and expression
of genes.
 Ribonucleic acid (RNA) is a linear
molecule composed of four types of smaller
molecules called ribonucleotide bases:
adenine(A), cytosine(C),
guanine(G), uracil (U).
http://www.phschool.com/science/biology_place/biocoach/transcription/difgns.html

9. types of RNA (each encoded by its own type of gene)
 mRNA-Messenger RNA: Encodes amino acid sequence of a polypeptide.
 tRNA- Transfer RNA: Brings amino acids to ribosomes during translation.
 rRNA- Ribosomal RNA: With ribosomal proteins, makes up the ribosomes,
the organelles that translate the mRNA.
 snRNA-Small nuclear RNA: With proteins, forms complexes that are used in
RNA processing in eukaryotes. (Not found in prokaryotes.)

10. Biological difference between DNA and RNA