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DNA. 1/22/09. The homonculus. The Different Parts of a Nucleotide. Nitrogenous Base. Phosphate. Sugar. Fig. 16-5. Nitrogenous bases. Sugar–phosphate backbone 5 end. Thymine (T). Adenine (A). Cytosine (C). DNA nucleotide. Phosphate.
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DNA 1/22/09 The homonculus
The Different Parts of a Nucleotide Nitrogenous Base Phosphate Sugar
Fig. 16-5 Nitrogenous bases Sugar–phosphate backbone 5 end Thymine (T) Adenine (A) Cytosine (C) DNA nucleotide Phosphate Sugar (deoxyribose) 3 end Guanine (G)
Percentage of Nitrogenous Bases in Four Organisms Source of DNA A T G C Streptococcus 29.8 31.6 20.5 18.0 Yeast 31.3 32.9 18.7 17.1 Herring 27.8 27.5 22.2 22.6 Human 30.9 29.4 19.9 19.8
Fig. 16-6 (b) Franklin’s X-ray diffraction photograph of DNA (a) Rosalind Franklin
Fig. 16-7a 5 end Hydrogen bond 3 end 1 nm 3.4 nm 3 end 0.34 nm 5 end (a) Key features of DNA structure (b) Partial chemical structure
Fig. 16-8 Adenine (A) Thymine (T) Cytosine (C) Guanine (G)
Fig. 16-12 Origin of replication Parental (template) strand Daughter (new) strand Replication fork Double- stranded DNA molecule Replication bubble 0.5 µm Two daughter DNA molecules (a) Origins of replication in E. coli Origin of replication Double-stranded DNA molecule Parental (template) strand Daughter (new) strand 0.25 µm Replication fork Bubble Two daughter DNA molecules (b) Origins of replication in eukaryotes
Fig. 16-14 New strand 5 end Template strand 3 end 5 end 3 end Sugar T A A T Base Phosphate C G C G G C G C DNA polymerase 3 end A A T T 3 end Pyrophosphate C C Nucleoside triphosphate 5 end 5 end
Fig. 16-15 Overview Origin of replication Leading strand Lagging strand Primer Lagging strand Leading strand Overall directions of replication Origin of replication 3 5 RNA primer 5 “Sliding clamp” 3 5 DNA poll III Parental DNA 3 5 5 3 5
Fig. 16-16a Overview Origin of replication Leading strand Lagging strand Lagging strand 2 1 Leading strand Overall directions of replication
Fig. 16-16b1 3 5 3 5 Template strand
Fig. 16-16b2 3 5 3 5 Template strand 3 5 3 RNA primer 1 5
Fig. 16-16b3 3 5 3 5 Template strand 3 5 3 RNA primer 1 5 3 Okazaki fragment 5 3 1 5
Fig. 16-16b4 3 5 3 5 Template strand 3 5 3 RNA primer 1 5 3 Okazaki fragment 5 3 1 5 3 5 3 2 5 1
Fig. 16-16b5 3 5 3 5 Template strand 3 5 3 RNA primer 1 5 3 Okazaki fragment 5 3 1 5 3 5 3 2 5 1 5 3 3 5 1 2
Fig. 16-16b6 3 5 3 5 Template strand 3 5 3 RNA primer 1 5 3 Okazaki fragment 5 3 1 5 3 5 3 2 5 1 5 3 3 5 1 2 5 3 3 5 1 2 Overall direction of replication
Fig. 16-18 Nucleotide Excision Repair Nuclease DNA polymerase DNA ligase
Fig. 16-19 5 Ends of parental DNA strands Leading strand Lagging strand 3 The chromosome end replication problem Last fragment Previous fragment RNA primer Lagging strand 5 3 Parental strand Removal of primers and replacement with DNA where a 3 end is available 5 3 Second round of replication 5 New leading strand 3 5 New lagging strand 3 Further rounds of replication Shorter and shorter daughter molecules