Cell Physiology

Thought Questions for Exam 3

Hao Nguyen


1.   Define a cell cycle.  How is the cell cycle controlled or regulated?  Why does the cell cycle need to be regulated?  What might happen if the cell cycle is not well-            regulated or not regulated at all?


2.   What are the functions of Cdk's and Cyclins?  How are they involved in cell cycle regulation?  What pathway or pathways do they activate?  How are the activities             of these proteins (Cdk and Cyclin) themselves regulated?


3.   What is apoptosis?  What is its function in cell cycle regulation?  Describe the difference between and intrinsic apoptotic pathway and an extrinsic apoptotic        pathway.  What might happen if a cell is unable to undergo apoptosis when required?


4.   What roles do the various types of receptors and signal transduction pathways play in the activation of cell proliferation and cell death?


5.   How is the Cdk-1:CyclinB activity regulated?  Why does it have to be regulated?  What is/are the function(s) of the activated Cdk-1:CyclinB?  Name and describe    the        functions of the different forms of the Cdk-1:CyclinB dimer.  How is the regulation of Cdk-1:CyclinB activity correlated with the various phases of mitosis?


6.   What is the function(s) of cdc-25?  How is its activity regulated?  Why does it have to be regulated?


7.   What is cell cycle arrest?  What is the function(s) of cell cycle arrest?  When is it activated?  How is it regulated?  What is the link between cell cycle arrest and      apoptosis?  What may happen if cell cycle arrest were absent?


8.   Name and describe structural and morphological changes associated with cell division [discussed in class].  Describe the molecular mechanisms of these             processes.


9.   Describe structural and morphological changes associated with apoptosis.  Explain how each change/process contributes to the intended result.  What is the    intended result of apoptosis?  What is the difference between an Intrinsic Apoptotic Pathway and an Extrinsic Apoptotic Pathway?


10.  Describe the two types of asymmetric cell division in relation to cell differentiation.  What is a stem cell?  What are the distinctions among the different types of           stem cells?  How are cell influenced to differentiate?


11.  How do the various levels of DNA mutation influence cell function?  How do DNA mutations influence the ability of a cell progressing through the cell cycle?