Biotechnology: DNA Recap

1. Biotechnology: DNA Recap Transcription and Translation

2. The Central Dogma • DNA  RNA  Protein

3. Transcription • DNA  RNA • DNA (double stranded) is transcribed in the NUCLEUS with the aid of an enzyme called RNA polymerase.

4. Transcription • RNA polymerase unwinds and unlinks the two strands of DNA. • The two strands are now separated.

5. Transcription: • One of them is called the CODING STRAND and the other is called the TEMPLATE STRAND.

6. Transcription • The TEMPLATE strand will used by RNA polymerase. • RNA polymerase adds the RNA base compliment to the DNA template to make the RNA STRAND .

7. Nucleotides In DNA: A always binds to TC always binds to G In RNA: A binds to U

8. Transcription • The newly formed RNA strand is the same as the coding strand except that U is replaced with T .

9. Transcription

10. Transcription

11. Transcription • The newly formed RNA strand is SINGLE STRANDED. • It gets processed (to mRNA) and leaves the nucleus through large holes in the nucleus called nuclear pores. • The next step is Translation!

12. Translation • RNA Protein • Occurs in the cytoplasm with the aid of a ribosome. • Each strand of RNA codes for multiple amino acids.

13. Translation • The RNA is read by reading the codon sequence. • A codon is 3 BASE PAIRS LONG. Each codon codes for an amino acid. • RNA strand: AUCGUUAUUGCG

14. Translation • RNA strand: AUCGUUAUUGCG

15. The appropriate amino acid is then placed on the growing polypeptide chain. • The polypeptide chain then undergoes structural changes to become a functional protein!