1. Chromosome Structure and DNA Replication
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Chromosome Structure and DNA Replication

2. Chromosomes Prokaryotic cells Eukaryotic cells One single chromosome
Shape?
Eukaryotic cells
Typically have ~1000 times the amount of DNA as prokaryotes
Chromosome number varies between species
Humans are 46, potato is 48 (4 sets of 12)

4. DNA length Very long Requires condensing in order to fit in cells
DNA in E. Coli (bacteria) is over 1 million bases long, over 1 mm in length
Human DNA is roughly 3 billion bases long, length is over 1 meter long
Requires condensing in order to fit in cells
Forms chromatin when tightly coiled around histone proteins
Condenses into chromosomes during prophase

7. DNA Replication Each strand of DNA can be used to create a new one
Replication forks: areas where separation of DNA strands and replication of new strands begins
Essential for cell division to occur

8. DNA Replication
Double helix separates, then each strand has a new complimentary strand created by DNA polymerase
A to T and G to C
DNA helicase: “unzips” the DNA
Essential step for DNA polymerase to bind to DNA
DNA polymerase
Brings the new nucleotides together
Responsible for proofreading the new DNA strands