Problem Set #1 - Cell Bio PDF

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Cell Bio...

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Problem Set 1

Principles of Cell Biology

Fall 2016

Directions: Problem sets will have three types of questions. The "Conventional" type question won't be labeled as such and can be typically answered by referring to your text book or lecture notes. The "Challenge" question (labeled "Challenge") is one that by design will be challenging for you to answer and may/may not require outside sources. Its skill level is designed to be above what is expected in the course. These Challenge questions will be more typical of later problem sets. Finally, the "Opinion" question (labeled "Opinion") has no right or wrong answer and asks you to think about the science and ethics of the question. 1. Organs on a chip (Labs on a chip) have been a major focus of many institutions including Harvard and MIT as well as others. What are these devices and how might they be useful?

2. Cell and organismic aging is a challenging area with many ideas that have been presented. In this regard how do telomeres, sirtuin genes, mitophagy and stem cells relate to this topic?

3. Speaking of stem cells, one of the hottest topics in cancer research is cancer stem cells and circulating tumor cells (CTCs). Explain the difference between these two cell types and their importance in the clinical diagnosis and treatment of cancer. 4. (Challenge) As referenced in the previous question, the scientific community is actively engaged in trying to develop new methods for cancer treatment, detection and drug discovery. Figure 4.7 describes a process that is referred to as high throughput screening for anti cancer drugs. a. What is high throughput screening and how do libraries relate to this process?

b. You are asked to design a high throughput system that can achieve what is shown in Figure 4.7. What would be the critical components of a high throughput system that could achieve what is described in Figure 4.7?

c. In developing a library of compounds to test why would you need to first consider the hydrophobicity or hydrophilicity of these compounds?

5. Stem cells were referenced earlier in relationship to their nasty role in cancer but stem cells also have a more positive side to their clinical applications. Explain this statement and weigh the pros and cons of adult stem cells versus human embryonic stem cells (hESCs) in clinical and non clinical applications.

6. What is photobleaching and why is it important to consider in point scanning confocal microscopy, spinning disk confocal microscopy and FRAP?

7. Both light and electron microscopy can be accomplished using tissue embedding techniques or cryosections. Discuss the differences between the two and why you would use one or the other in a typical application. 8. Nanoparticles have been favorite experimental entities used by physicists for years but now have become popular in cell and molecular biology as well as the medical field. List a few applications of nanoparticles in these two areas.

9. What are epitope tags and how do they relate to immunocytochemistry?

10. Monoclonal antibodies (mAbs) were developed in the 1970s and 1980s and have major advantages over polyclonal antibodies. Furthermore well as conjugated mAbs. The following questions address this theme. a. What is the difference between polyclonal antibodies and monoclonal antib b. mAbs are regarded as "biologics". What is the definition of a biologic?

c. What is a conjugated mAB and how might ricin be used in this regard?

d. Is it possible to do a double label fluorescent immunocytochemistry experiment? If so, what are the critical issues that need consideration if this is, indeed, possible to execute?

11. Two photon microscopy and confocal microscopy are both used to visualize fluorochromes but each has its own virtues and limitations. How does two photon microscopy work and what distinct advantage does it have over confocal microscopy?

12. (Opinion) NIH has asked through a formal public announcement posted on 8/6/2016 and terminated (website access removed) on 9/6/2016 for comments from US citizens on whether this agency should fund the creation of human-animal chimeras. NIH and the US has steadfastly made generation of human-animal chimeras illegal but NIH is being pushed by certain science lobbyists and others to reconsider its stand. NIH took the same public comment approach on the use of hESCs when President Obama took office now nearly 8 years ago. So this protocol is typical of controversial issues. What might be the pros and cons of supporting this type of work?...