LIFESCI 3 Study Guide - Midterm Guide: Nucleoside, Methyl Group, Carcinogen
Document Summary
Dna repair pathways and lab techniques iii. Dna transcription: termination in prokaryotes and initiation in eukaryotes. Increase complexity of organism, increase genome size, increase number of genes, decrease gene density (average # genes per mb of genomic dna) In 65kb stretch of dna, bacteria has mostly genes, few intergenetic sequence. In 65 kb stretch of dna, humans have almost no genes. Introns (non-coding sequence that get cut out during rna splicing) Regulatory seq (control and regulate expression of genes. Repetitive dna (almost half of our genome; non coding) 1. 5 % of genome actually codes for genes transposable elements. Cellular dna associates with proteins and is packaged in chromosomes. Many proteins (make up half the molecular weight of the chromosome) Compact the huge dna into a small size to fit in the nucleus. To transport dna to daughter cells during replication. Can only be replicated in host cell. Has reverse transcriptase: produces dna from its rna genome once inside host cell.
