chapter 7 molecular organization of chromosomes. the range of genome sizes in the animal & plant...
Post on 20-Dec-2015
230 views
TRANSCRIPT
![Page 1: Chapter 7 Molecular Organization of Chromosomes. The range of genome sizes in the animal & plant kingdoms](https://reader036.vdocuments.us/reader036/viewer/2022062308/56649d425503460f94a1e136/html5/thumbnails/1.jpg)
Chapter 7Chapter 7
Molecular Organization of Molecular Organization of ChromosomesChromosomes
![Page 2: Chapter 7 Molecular Organization of Chromosomes. The range of genome sizes in the animal & plant kingdoms](https://reader036.vdocuments.us/reader036/viewer/2022062308/56649d425503460f94a1e136/html5/thumbnails/2.jpg)
The range of genome sizes The range of genome sizes in the animal & plant kingdomsin the animal & plant kingdoms
![Page 3: Chapter 7 Molecular Organization of Chromosomes. The range of genome sizes in the animal & plant kingdoms](https://reader036.vdocuments.us/reader036/viewer/2022062308/56649d425503460f94a1e136/html5/thumbnails/3.jpg)
DNA can assume alternative conformations DNA can assume alternative conformations such as partially melted or supercoiled such as partially melted or supercoiled
statesstates
![Page 4: Chapter 7 Molecular Organization of Chromosomes. The range of genome sizes in the animal & plant kingdoms](https://reader036.vdocuments.us/reader036/viewer/2022062308/56649d425503460f94a1e136/html5/thumbnails/4.jpg)
Mechanism of action of a Mechanism of action of a topoisomerasetopoisomerase
![Page 5: Chapter 7 Molecular Organization of Chromosomes. The range of genome sizes in the animal & plant kingdoms](https://reader036.vdocuments.us/reader036/viewer/2022062308/56649d425503460f94a1e136/html5/thumbnails/5.jpg)
Mechanism of folding of a bacterial Mechanism of folding of a bacterial chromosomechromosome
There are many supercoiled loops (~100 in E. coli) attached to a central core. Each loop can be independently relaxed or condensed.
![Page 6: Chapter 7 Molecular Organization of Chromosomes. The range of genome sizes in the animal & plant kingdoms](https://reader036.vdocuments.us/reader036/viewer/2022062308/56649d425503460f94a1e136/html5/thumbnails/6.jpg)
Packing of DNA in an eukaryotic cell involves wrapping Packing of DNA in an eukaryotic cell involves wrapping around a core of basic (positively charged) proteins called around a core of basic (positively charged) proteins called
histoneshistones
![Page 7: Chapter 7 Molecular Organization of Chromosomes. The range of genome sizes in the animal & plant kingdoms](https://reader036.vdocuments.us/reader036/viewer/2022062308/56649d425503460f94a1e136/html5/thumbnails/7.jpg)
Steps in the folding of DNA Steps in the folding of DNA to create an eukaryotic chromosometo create an eukaryotic chromosome
![Page 8: Chapter 7 Molecular Organization of Chromosomes. The range of genome sizes in the animal & plant kingdoms](https://reader036.vdocuments.us/reader036/viewer/2022062308/56649d425503460f94a1e136/html5/thumbnails/8.jpg)
The rate of renaturation of single stranded DNA The rate of renaturation of single stranded DNA depends upon the concentration and sequence complexitydepends upon the concentration and sequence complexity
![Page 9: Chapter 7 Molecular Organization of Chromosomes. The range of genome sizes in the animal & plant kingdoms](https://reader036.vdocuments.us/reader036/viewer/2022062308/56649d425503460f94a1e136/html5/thumbnails/9.jpg)
The rates of renaturation of DNAs The rates of renaturation of DNAs with different kinetic complexitieswith different kinetic complexities
![Page 10: Chapter 7 Molecular Organization of Chromosomes. The range of genome sizes in the animal & plant kingdoms](https://reader036.vdocuments.us/reader036/viewer/2022062308/56649d425503460f94a1e136/html5/thumbnails/10.jpg)
DNA of an eukaryotic cell has several DNA of an eukaryotic cell has several components components
with different kinetic complexitieswith different kinetic complexities
![Page 11: Chapter 7 Molecular Organization of Chromosomes. The range of genome sizes in the animal & plant kingdoms](https://reader036.vdocuments.us/reader036/viewer/2022062308/56649d425503460f94a1e136/html5/thumbnails/11.jpg)
DNA with low kinetic complexity is located in the DNA with low kinetic complexity is located in the middle (near the centromere) and at the endsmiddle (near the centromere) and at the ends
(near the telomeres) of a chromosome (near the telomeres) of a chromosome
![Page 12: Chapter 7 Molecular Organization of Chromosomes. The range of genome sizes in the animal & plant kingdoms](https://reader036.vdocuments.us/reader036/viewer/2022062308/56649d425503460f94a1e136/html5/thumbnails/12.jpg)
Structure of the centromere Structure of the centromere in a in a
SaccharomycesSaccharomyces chromosome chromosome
The centromere DNA has 4 centromere determining
elements (CDEs)
![Page 13: Chapter 7 Molecular Organization of Chromosomes. The range of genome sizes in the animal & plant kingdoms](https://reader036.vdocuments.us/reader036/viewer/2022062308/56649d425503460f94a1e136/html5/thumbnails/13.jpg)
Replication of telomere DNA repeatsReplication of telomere DNA repeats
![Page 14: Chapter 7 Molecular Organization of Chromosomes. The range of genome sizes in the animal & plant kingdoms](https://reader036.vdocuments.us/reader036/viewer/2022062308/56649d425503460f94a1e136/html5/thumbnails/14.jpg)
Mechanism of replication of telomere Mechanism of replication of telomere DNA DNA
by the enzyme telomeraseby the enzyme telomerase
The enzyme telomerase has a
RNA molecule that serves as the template
for telomere DNA synthesis.
![Page 15: Chapter 7 Molecular Organization of Chromosomes. The range of genome sizes in the animal & plant kingdoms](https://reader036.vdocuments.us/reader036/viewer/2022062308/56649d425503460f94a1e136/html5/thumbnails/15.jpg)
Telomerase has protein and Telomerase has protein and RNA componentsRNA components
![Page 16: Chapter 7 Molecular Organization of Chromosomes. The range of genome sizes in the animal & plant kingdoms](https://reader036.vdocuments.us/reader036/viewer/2022062308/56649d425503460f94a1e136/html5/thumbnails/16.jpg)
Proposed 4-stranded structure of Proposed 4-stranded structure of telomere DNA telomere DNA
in two protozoansin two protozoans
![Page 17: Chapter 7 Molecular Organization of Chromosomes. The range of genome sizes in the animal & plant kingdoms](https://reader036.vdocuments.us/reader036/viewer/2022062308/56649d425503460f94a1e136/html5/thumbnails/17.jpg)
Hydrogen bonding Hydrogen bonding structure of G quartetstructure of G quartet