i am HAFIZ M WASEEM from mailsi vehari BSc in science college Multan Pakistan MSC university of education Lahore Pakistan I love Pakistan and my teachers

1. HAFIZ
MUHAMMAD
WASEEM
Nucleic Acids (DNA & RNA)
A Brief Introduction
NUCLEIC ACID
• Deoxyribonucleic acid (DNA) and ribonucleic acid (RNA) are the molecular repositories
of genetic information.
• The structure of every protein, and ultimately of every biomolecule and cellular
component, is a product of information programmed into the nucleotide sequence of a
cell’s nucleic acids.
• The ability to store and transmit genetic information from one generation to the next is a
fundamental condition for life.
• Nucleic acid are polymers composed of monomer units called nucleotides in a
conserved sequence
 Each nucleotide iscomposedof one of following nitrogen-bases:
 Cytosine (C)
 Guanine (G)

2.  Adenine (A)
 Thymine (T)
 Uracil (U)
 The purine and pyrimidine bases in cells are linked to deoxyribose and in this form are
termed, nucleosides
 Nucleosides are phosphorylated termed as nucleotides

3.  The nucleotides are joined to one another in a chain by covalent bonds between the sugar
of one nucleotide and the phosphate of the next.

4.  Each base A, C, T/U, or G—can be considered as a letter in a four-letter alphabet that
spells out biological messages in the chemical structure of the DNA /RNA which spell
out the linear sequence of amino acids in a protein

5. • The complete set of information in an organism's DNA is called its genome and it
carries the information for all the proteins the organism will ever synthesize
• A segment of a DNA molecule that contains the information required for the synthesis of
a functional biological product, whether protein or RNA, is referred to as a gene.
• A cell typically has many thousands of genes, and DNA molecules, not surprisingly,
tend to be very large.
• The storage and transmission of biological information are the only known functions of
DNA.
• The exact correspondence between nucleotide of DNA and amino acid alphabets of
proteins is the genetic code
TYPES OF RNA
• RNAs have a broader range of functions, and several classes are found in cells.
• Messenger RNAs (mRNAs) are intermediaries, carrying genetic information from
one or a few genes to a ribosome, where the corresponding proteins can be synthesized.
• Ribosomal RNAs (rRNAs) are components of ribosomes, the complexes that carry out
the synthesis of proteins.
• Transfer RNAs (tRNAs) are adapter molecules that faithfully translate the
information in mRNA into a specific sequence of amino acids.
CENTRAL DOGMA
 The central dogma of molecular biology describes the two-step process, transcription
and translation, by which the information in genes flows into proteins
 DNA → RNA → protein.
 Transcription is the synthesis of an RNA copy of a segment of DNA by the enzyme RNA
polymerase.