| Describe 3 phases in DNA replication | Initiation
- recognising origin of replication
- action of DNA polymerase and DNA helicase
Elongation
- 5' to 3' chain growth
Termination
- When replication forks meet
- action of DNA ligase |
| Where does transcription and translation occur? | Transcription
- in the nucleus
Translation
- in the cytoplasm |
| Describe 3 phases in transcription | Initiation
- promoter recognition and blinding
- e.g) TATA
- RNA polymerase binds to the site
Elongation
- 5' to 3' chain growth, copy of mRNA by complementary base pairing
Termination
- sequence dependent termination of of RNA chain growth |
| Describe the process of transformation from pre-mRNA to mature mRNA | Capping
- addition of 5' cap
- protection against degradation of polynucleotide at 5' end
Tailing/Polyadenylation
- addition of 3'polyA tail
- protection against degradation of polynucleotide at 3' end
Splicing
- removal of introns
- spliceosome cut introns and join exons together |
| Describe 3 phases in translation | Initiation
- Starting codon recognition and binding
- formation of functional ribosome
- recognition done by hydrogen bond between codon and anticodon
Elongation
- Addition of 5' nitrogen to 3' carbon, creating peptide bond (N to C chain growth)
- tRNA synthetase acts as a catalyst, binds tRNA with aminoacid
Termination
- stopping codon recognition |
