Main Points of Modules 10.8-10.10

1. Glow of genetic information occurs by transcription and translation.

2. Transcription occurs in the nucleus.

3. Translation takes place in the cytoplasm.

4. Genetic information exists as base triplets called codons.

5. Genetic code is universal.

6. Sixty-one of the 64 codons code for amino acids; there are three stop codons and one start codon.

7. The start codon is AUG, which also codes for the amino acid, methionine.

8. It occurs in three stages: initiation, elongation, termination.

9. RNA polymerase catalyses transcription.

10. Transcription starts at a region called promoter and ends at the terminator sequence.

11. RNA is of three types: mRNA, tRNA and rRNA.

12. mRNA is processed before translation.

13. There are four steps in RNA processing: addition of a cap, addition of a poly-A tail, removal of introns (non-coding sequences), splicing of exons (coding sequences) called RNA splicing.

14. The processed RNA goes out from the nucleus into the cytoplasm.