Molecular Biology

Thought Questions for Exam 3

Hao Nguyen

 

1.   Describe the initiation of translation under normal condition.  Where does this take place within the cell?  Name and describe the function(s) of all molecules and structures that are involved in translation.  How is translation terminated?

 

2.   Describe the Wobble hypothesis.  Know the mathematical basis for this hypothesis.  What might happen to translation if the activities described by the Wobble hypothesis were not true?  Can translation still occur?

 

3.   Think about situations where a cell may want to regulate translation.  Which step or steps of translation is more likely to be regulated (initiation, elongation, or termination)?  How would the cell regulate translation?  Why would a cell want to inhibit translation after having spent all that time and energy undergoing transcription and post-transcriptional modifications?  Why isn't the initiation of translation a spontaneous event as long as the mRNA's are present in the cytoplasm?

 

4.   How is the initiation of translation altered during stress or viral infection?  Describe the difference between Cap-dependent and Cap-independent initiation of translation.

 

5.   What is the correlation between a codon and an anticodon?  What is the correlation between an anticodon and an amino acid?  What is the correlation between a codon and an amino acid?  What is the correlation between an aminoacyl-tRNA synthetase and the tRNA that is being charged?

 

6.   What may happen if one of the types of post-translational modification cannot occur in the cell?  What may happen if none of the post-translational modifications can occur in the cell?  Would the cell still produce a functional protein?  Would the cell still be able to carry out translation?

 

7.   What might happen to translation if a cell is not able to synthesize functional chaperone proteins?  What might happen to post-translation modification if a cell is not able to synthesize functional chaperone proteins?

 

8.   What is post-translational modification and why is it important?  Describe all types of post-translational modifications and indicate where each occurs.

 

9.   How does the regulation of gene expression contribute to the differentiation of a cell and development of an organism?  How does the regulation of gene expression contribute to phenotypic expression from various genotypes?  Integrate Molecular Biology into the concept of epistasis, pleiotropy, and polygenic inheritance.

 

10.  Why is the idea of "One Gene, One protein" flawed [at so many levels]?

 

11.  Describe Cell Differentiation.  What are stem cells?  What are the different types of stem cell?

 

12. Describe the process of DNA purification/isolation.  What is the function of ethanol?  What is the function of proteinase K?  What is the function of RNase?  What happens if you don't have any or all of these items?

 

13.  What is a vector?  Describe the difference between a plasmid and a cosmid.  What is/are the advantage and disadvantage of both complexes?  How are they used in DNA cloning?  What is a competent cell?  Why is it necessary to make these cells?  What is the problem if you don't have competent cells?

 

14.  Describe the process of Polymerase Chain Reaction.  What is a primer and what is its function?  What is Taq polymerase?  What is the uniqueness/significance of this enzyme?  What is RT-PCR?  What is Real Time RT-PCR?