curbano's blog

Cancer research is so challenging because there are SO many different influences. Many things we encounter in our lives, such as radiation, technology, red meat, smoking, etc., are said to cause cancer, yet we still expose ourselves to those things. Clearly we can't avoid everything that is said to cause cancer, but I find it interesting that only 1% of cancers are found to be hereditary. In cancer, I would expect to see p53 mutations or there could be many other signaling/survival/etc pathways influenced in cancers. For example, we talked about the Bcr-AbI mutation that leads to a certain type of leukemia.

When we were first assigned to make about 6 drafts per week, I was a little intimidated. I was not sure if I would be able to write that much, especially since none of my other classes required much writing. At first I would work on exercises for the Writing in Biology for my draft entries as well as my Life After Biology seminar. I also would make draft entries for my Cellular and Molecular Biology class. With writing assignments, I often do not spend much time creating drafts or editing my work. Doing draft entries prevented me from procrastinating on most of my assignments. I think making several drafts allows us to reevaluate our work and make improvements over time. It can be challenging to see mistakes or room for improvement. Some weeks it was challenging for me to make enough drafts since sometimes I felt that my work came out well. Overall, I thought doing draft entries made me a better writer and helped me organize my thoughts and projects more efficiently.

Chromosome shortening can be life threatening to any organism. If a chromosome shortens every time it gets replicated, vital and important information is going to get deleted. This will eventually lead to terrible birth defects or the cells not being able to function properly. Most likely death will occur. Because of this, there must be a mechanism to prevent shortening from occurring. DNA replication occurs so much to go right and must be very precise. If the alignment is not proper, chromosome shortening will most likely occur or errors will occur in the process. I feel like cells that have an error will be sent to cell death. It now makes sense to me why HIV can be such a deadly virus for humans. The virus infects and alters the DNA. In addition to that, it reverses transcriptase, which makes DNA from RNA templates. This causes a half DNA half RNA double stranded sequence to form, which ultimately leads to a single strand of DNA. A single DNA strand cannot be duplicated properly.

Temperature affects many physiological and biological processes in the body. Spiders are ectothermic organisms, so they are unable to regulate their body temperatures relative to their environment. As a result, changes in temperature can have a large impact on their metabolic rate and overall activity. Our project focuses on the effect of temperature on web production in P. phalangioides. To study this, we created three different environments with varying temperatures for spiders to live in and create webs. We had a cool environment that averaged at 11.6 degrees celsius, warm environment at 26.2 degrees celsius, and a control environment at 19.4 degrees celsius. We put three spiders, each in their own cup, in each environment and allowed them to produce webs for five days. We then compared the final weights of the webs in the different environments. It was concluded that spiders in cooler environments typically yielded lighter webs than spiders in warmer environments. 

The fact that there is a stretch of RNA at the 5' end of the Okazaki fragment emphasizes the fact that RNA does not need anything but itself to start replication. The leading strand only needs one RNA primer to begin replication since it can replicate continuously. Since the lagging strand replicated discontinuously, primers must be put down after Okazaki fragments. If this did not occur or if there was a mutation in these primers, the lagging strand would not carry out replication correctly or at all.  E.coli has 5 DNA polymerases while eukaryotes have about 13. It makes sense that E. coli would have less DNA polymerases than eukaryotic DNA polymerases since eukaryotic organisms are more complex than a bacteria like E. coli. However, I did not know that there were at least 13 DNA polymerases in eukaryotes and I'm a little surprised. I have learned about several different DNA polymerases. They each seem to have their own specific function in the DNA replication process. It is important to have several DNA polymerases in case one has a mutation or fails. This will help prevent the entire process from failing. n nick translation, DNA polymerase I cuts/nicks random parts of the DNA to tag certain parts of the DNA. The tagged sequence can then be used as a probe or for IF staining.

In many ways, RNA is the same as DNA. They both represent genetic information. They are kind of like different translations or languages of the same information. DNA has adenine, guanine, cytosine, and thymine. RNA has all the same expect thymine is replaced with uracil. Since they have so much overlapping similarity, it is thought that the first living organisms were made from RNA, and it eventually evolved to DNA. I never really considered that nucleotides would have other functions in the cell other than genetic information, but it makes sense. It makes sense that they would be involved in intracellular signaling and regulation of enzyme activity. I would think that transcription factors and things like post-translation modifications would be the nucleotides involved in signaling s well as enzyme activity. However, I wonder how nucleotides influence energy transduction. Hydrogen bonding and van der waals interactions help stabilize the structure of DNA and helps it maintain the double helix shape. Since two hydrogen bonds are between adenine and thymine while guanine and cytosine have three hydrogen bonds, G and C would be more stable. It is important for DNA to be able to denature itself as well as renature itself. This reminds me of an on and off switch. Denaturing means breaking apart DNA bonds/structure. Increasing temperature and signals can lead to the denature of DNA. Renaturing DNA brings the nucleotides back together.

While I know GTP-tubulin is what tells the microtubule to polymerize and GDP-tubulin tells the microtubules to depolymerize, I would assume something must initiate/signal the GTP or GDP to bind to tubulin. I am curious how this signaling system works and how the microtubule knows whether or not it wants to lengthen or shorten. Microtubules have a variety of important functions in the cell. They help with chromosome segregation, cell structure, cell movement, and directionality. The article does not say exactly how microtubules influence directionality, but I would think that the motor proteins, especially kinesin and dynein, play a large role in direction and movement.

It is important to remember that the plus end and minus end do not reflect the charge of the microtubules. While polymerization occurs at both the plus and minus ends, polymerization occurs much more quickly at the plus end. Additionally, the alpha subunits are exposed at the minus end while beta subunits are exposed at the plus end. I wonder if the alpha or beta subunits have any influence the speed of polymerization. We talked a little bit about the gamma tubulin in class. y-tubulin plays an important role in microtubule development since it initiates the nucleation/formation of microtubules. Since it initiates formation, the y-tubulin complex is located in the centrosome. It makes sense that it would be located in the centrosome since that is where spindle production occurs. If there is a mutation at this complex, microtubules will most likely not form properly and possibly lead to improper chromosome segregation.

I never really considered how gene therapy and editing could ultimately lead to a transformation society values, economic status, injustice, and more. If gene therapy becomes more popular in the medical field, the division of classes will be even more noticeable. A lot of gene therapy costs hundreds of thousands of dollars, so only very wealthy people can get cured for certain diseases and disabilities. Is this fair to allow only the top 1% to get cured for these things? It is hard to know, because many people cannot afford chemotherapy for cancer, which is such a common treatment in our society. Also, I have heard the idea about using gene therapy to help parents decide the appearance of their children. While it is good to know if a future child is likely ro have a condition such as Down syndrome, is it ethically okay for us to start picking and choosing characteristics we like for our children? How would a child feel about finding out their parents put them together like a Sims character?

The cytoskeleton  plays a huge role in the function of an organism and cell. The main function of cytoskeletons is to help maintain the structure of the cell. An important characteristic of cytoskeleton structures is dynamic instability, which allows these structures to polymerize and depolymerize. Some common cytoskeleton structures in the cell include microtubules and actin. Dynamic instability allows these structures to move and help the cell carry out processes like chromosome segregation (microtubules) and muscle contraction (actin). In chromosome segregation, microtubules must be able to become shorter to pull chromosomes apart. It would be difficult for the cell to carry out vital processes and maintain its structure without the help of the cytoskeleton.