Discussion 7: Problem Solving II
MCB 150
Problem Solving II
1. Describe the synthesis of ATP from ADP and Pi via oxidative
phosphorylation backwards through the electron transport chain,
Krebs cycle, and glycolysis. Also trace the fate of the carbons and
hydrogens in the glucose at the "end" of this (backwards) process.
o At each step, explain how the "stage was set" so the current
process is allowed to proceed.
2. Compare and contrast DNA Polymerase I and DNA Polymerase III in
E. coli.
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What are the requirements for each to do its job?
What can Pol I do that Pol III cannot?
What has it appeared to "sacrifice" in order to gain this
additional activity?
What would be the long-term consequence if Pol I lost this
unique ability?
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Discussion 7: Problem Solving II
MCB 150
3. Why can't DNA Polymerase I seal the nicks in the sugar-phosphate
backbone? What fills this role?
4. What is the sigma factor looking for specifically in a eukaryotic
promoter region?
5. Is it a coincidence that promoter regions, such as the -10 site of the
E. coli promoter, are often rich in A-T base pairs? If not, explain the
significance.
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Discussion 7: Problem Solving II
MCB 150
6. What steps occur in the processing of a eukaryotic mRNA, and
where do these steps occur?
7. Describe the three phases of translation, pointing out differences
between bacteria and eukaryotes (and archae) where relevant.
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