DNA Replication and Repair
DNA Replication and Repair
DNA contains cell informationCompletecellDNAsequence=genome Genome of bacteria usually circular (Can be linear)Bacterial genome = 0.6 - 9.4 million bpHumangenome=4billionbp1000xaslargeas E.coli But 8× genes: 30,000 (us) vs. 4,000 (E. coli)E.coli genes uselessDNA sequence:About 1000 bases in typical bacterial gene:3000to2.4millioninhumangene
DNA contains cell information Complete cell DNA sequence = genome Genome of bacteria usually circular (Can be linear) Bacterial genome = 0.6 – 9.4 million bp Human genome = 4 billion bp 1000× as large as E. coli But 8× genes: 30,000 (us) vs. 4,000 (E. coli) E. coli genes use less DNA sequence • About 1000 bases in typical bacterial gene • 3000 to 2.4 million in human gene
deoxyriboseOHOHNucleic acidsstructure(Deoxy) Ribose (A sugar)5'end3phosphategroups on5'carbonThymin 5'phosphateof onenucleotideAdenine(A)links to 3" OH of previousnucleotide2-DeoxyriboBase attached to sugarPhosphodiestbond
Nucleic acids structure (Deoxy) Ribose (A sugar) 3 phosphate groups on 5’ carbon 5’ phosphate of one nucleotide links to 3’ OH of previous nucleotide Base attached to sugar
B-type DNA HelixA.Space-filledB.SurfaceDNA not a perfectly linear helix Contains major and minor grooves Gives regulatory proteins access toMajorMajorgroovegrooveinternal basesMust be able to recognize sequenceMinorMinor-groovegroove
B-type DNA Helix DNA not a perfectly linear helix Contains major and minor grooves Gives regulatory proteins access to internal bases Must be able to recognize sequence
+DNACoilingDNA double helix is a right-handed helix Thumb points from bottom to top口Strands coil in the same direction as thefingersDNATowerinPerth,Australia
DNA double helix is a right-handed helix Thumb points from bottom to top Strands coil in the same direction as the fingers