BSC 310 Lecture Notes - Lecture 17: Amine, Spliceosome, Reading Frame

• School: University of Alabama
• Department: Biological Sciences
• Course: BSC 310
• Professor: Julie Olson

Document Summary

Lecture 17- the unit of transcription & protein. Transcription unit- segment of dna transcribed into a single rna molecule that are bounded by transcription initiation and termination sites; can contain single or multiple genes. Most genes encode proteins but others encode nontranslated rnas, such as rrna or trna. Most transcription units for rrnas are longer than a single gene as each subunit is cotranscribed; the same is true for trna genes. These transcription units must be processed by cutting them into individual units to generate functional rrnas or trnas. Processing is rare in most prokaryotes but common in eukaryotes (cid:1) Most mrnas have short half-lives (a few minutes) before they are degraded; alternately rrnas and trnas are stable due to their folded structures which are not readily accessible for degradation by ribonucleases (cid:1) (cid:1) (cid:1) Genes encoding related enzymes are often clustered together so rna. Pol transcribes the entire group into a single long mrna (cid:1)