Sunday, 25 November 2007

Genetic engineering (3)

Structure and type of RNA

transfer RNA (tRNA)80-100 type
5S ribosomal RNA 1-2 type
5.8 Sribosomal RNA 1 type
16 S ribosomal RNA 1 type
23 S ribosomal RNA 1 type
18 S ribosomal RNA 1 type
28 S ribosomal RNA 1 type
messenger RNA (mRNA) many thousands type
heterogeneous nuclear RNA (hnRNA) many thousands type
small cytoplasmic RNA (scRNA)
small nuclear RNA (snRNA)

Size, organization, complexity of Genomes
Size and organization of genomes
1000 bp to 10000 mbp
dsDNA except virus: ssDNA, dsDNA, ssRNA, dsRNA, linear or circular, single or multiple
bacteria-circular dsDNA+protein
eukaryote-linear dsDNA (multile)+histone, non histone protein

left hand super helix 1.8 rounds, 145 bpDNA(2nm)+2H2A, 2H2B, 2H3, 2H4- nucleosome core particle(10nm)--> solenoid(30nm)-->filament(300nm)-->supercoiled(700nm)-->chromosome (metaphase 1400nm)
60 bp linker DNA+H1

heterochromatin-inactive-centromere, telomere
active chromatin-10%

packing ratio=DNA length/Final length average 1000-2000

Complexity of genome
unique sequence, repetitive sequence
slow component 1 copies-45% of genome
intermediate component 350 copies-30% of genome
fast component 500000 copies-25% of genome

satellite, minisatellite, microsatellite

Important of DNA
DNA replication
DNA transcription
Complexity of genome

No comments: