Protein Synthesis
Mutations
- Point mutations:changes in one DNA nucleotide pair
- Missense or nonsense mutations: caused by nucleotide-pair substitutions
- Nucleotide-pair insertions or deletions: can produce frameshift mutations
Mutations
- Point mutations:changes in one DNA nucleotide pair
- Missense or nonsense mutations: caused by nucleotide-pair substitutions
- Frameshift mutations: may produce frameshift mutations
Mutagens
Physical and chemical agents interact with DNA in ways that cause mutations
ex: UV light
Translation
2 Overall Protein Synthesis Steps
- Synthesis of a polypeptide whose amino acid sequence is decided by the nucleotide sequence in mRNA
- tRNA
- Anti-codon
- Stages of translation
- Initiation
- Elongation
- Termination
- P, A, and E binding sites
Transcription
- Pre-mRNA is synthesized in the nucleus using information in the template strand of DNA
- Promoter
- TATA box
- Start/stop codon
- Pre-mRNA is spliced and modified to produce mRNA
- Introns and exons
- Spliceosomes
- Capping
Prokaryotes v. Eukaryotes
In prokaryotes, mRNA produced by transcription is immediately translated because of the lack of a nucleus.
In eukaryotes, the nucleus provides a separate compartment for transcription.