It's shortly tell about the Transcription and translation

2. TRANSCRIPTION:
 Transcription is the process by which DNA is
transformed to mRNA.
 It involves two steps
 Pre messenger RNA is formed using the enzyme RNA
polymerase.
 mRNA is edited from Premessenger RNA using
Splicing.

3. Transcription Process:

4. Formation of PreMessenger RNA:
 The strand that contains the gene is called the sense strand,
while the complementary strand is the antisense strand.
 When RNA polymerase binds to the sigma(σ)factor
transcription starts and when it elongates “sigma” factor falls
off . Then RNA Polymerase elongates without any factors .
 Again when it binds to the Row(ϸ) factor transcription stops
(stop signal) and one strand of premessenger RNA is formed .

6. Formation of mRNA after Splicing:
SPLICING:
 The pre-messenger RNA thus formed contains introns (not
required).
 The pre-messenger RNA is chopped up to remove the
introns and create messenger RNA (mRNA) in a process
called RNA splicing.

8. Template and Coding Strands
5’–TCAGCTCGCTGCTAATGGCC–3’
3’–AGTCGAGCGACGATTACCGG–5’
5’–UCAGCUCGCUGCUAAUGGCC–3’
Sense (+) strand
DNA coding strand
Non-template strand
DNA template strand
antisense (-) strand
RNA transcript
transcription

9. Released mRNA

10. TRANSLATION:
 The mRNA formed in transcription is transported out of the
nucleus, into the cytoplasm.
 In Translation information contained in mRNA is used to make
the polypeptide.
 Here, it directs protein synthesis.
 Agents Involved:
 Transfer RNA (tRNA) is required for Translation.
 Ribosomes
 Release factor.

11. The process by which mRNA directs protein
synthesis with the assistance of tRNA is called
Translation. Nuclear
membrane
Transcription
RNA Processing
Translation
DNA
Pre-mRNA
mRNA
Ribosome
Protein

12. STAGES OF TRANSLATION:
 There are three important stages in Translation process namely
 Initiation
 Elongation
 Termination

13. INITIATION:
 Initiation begins when small subunits of Ribosome attach to the
Methylated cap of mRNA and moves to the Translation
Initiation site. ie) start codon (AUG)
 The tRNA that contain the anticodon (UAC) which is
complementary with the mRNA codon to which it binds.
 The initiator tRNA carries Methionine.

14. ELONGATION:
 The aminoacid-tRNA is able to base pair with the next codon
on the mRNA that binds at the “P” site associated with the
Elongation Factor.
 The preceding aminoacid link with the incoming aminoacid
using the Peptide Bond.
 The initiator tRNA is released from the P site.

16. TERMINATION:
 When Stop codon is encountered at the “A site” the
Release Factor enters the A site and the translation is
terminated.
 When the termination is reached the Ribosomes
dissociates and forms Protein.
 GTP releases the Polypeptide from the ribosome.

17. Any comments ?