BIOS 41 Midterm: Exam 3 Study Guide

• School: Lehigh University
• Department: Biological Sciences
• Course: BIOS 41
• Professor: krystale

Document Summary

Rna polymerase: catalyzes linkage of ribonucleotides, does not need a primer; synthesized 5" to 3", proofreads by backtracking (only one active site, unwinds template in bacteria. Dna polymerase: has second active site for proofreading, binds to a primer to begin replication, uses sliding clamp/clamp loader. Bacterial transcription: occurs in cytoplasm, haloenzyme rna polymerase + sigma factor. Bacterial v. eukaryotic transcription: bacterial cells contain a single rna polymerase, whereas eukaryotic cells have three, bacterial rna polymerase can initiate transcription without the help of additional proteins, whereas eukaryotic rna polymerases need general transcription factors. Increases stability of mrna mrna splicing: process only occurs in eukaryotes, exons: coding regions. Introns: noncoding regions: introns have gu at the 5" end and ag at the 3" end, polypyrimidine before 3" ag, spliceosomes, 5 small nuclear ribonucleoproteins (snrnps, small nuclear rnas + proteins, u1, u2, u4, u5.