Cellular Respiration

Submitted by sditelberg on Thu, 09/13/2018 - 11:02

One of the most important biological processes for all life on Earth is cellular respiration. This process takes place in an organelle known as the mitochondria, colloquially referred to as the "powerhouse of the cell." Three stages encompass cellular respiration: glycolysis, the Krebs cycle, and oxidative phosphorylation. The final stage is aerobic and generates the most ATP for the energy put in. Glycolysis is an anaerobic process that uses two ATP molecules and produces 4, resulting in a net gain of two ATP molecules. By breaking down glucose, the cell is able to tap into a bit of the energy stores located in the molecule. Glycolysis takes place outside the mitochondria in the cell's cytoplasm.

A molecule known as Acetyl CoA helps take the pyruvate, the ending molecule of glycolysis, into the matrix of the mitochondria. Here, the Krebs cycle occurs and many electrons are stripped from molecules and their intermediates to eventually be utilized in generating ATP. These electrons are picked up by electron carriers, such as NAD+ and FADH, which transport these electrons to the electron transport chain in oxidative phosphorylation. At the electron transport chain, electrons are pulled through a series of proteins by electronegative oxygen. Along the way, proton pumps establish a gradient in the intermembrane space of the mitochondria. The electrons eventually join with oxygen and are released as water, and the protons in the intermembrane space flow down their concentration gradient through ATP synthase. When ATP synthase spins, it generates ATP.

Reaction to Nussbaum's "Shame and People with Disabilities"

Submitted by mmaliha on Thu, 09/13/2018 - 10:29

Does the author recommend getting rid of amenities like telephone, staircases and visual signage , and making sure that everyone has access to the same resources? This way, the distinction between the "public world of ordinary citizens" and the "hidden world of disabled people" will lower a lot. But, it might be difficult to get people to comply with these changes, as they may see this as the reverse end of the norm: now instead of catering to abled people, catering to disabled people. 

Americans with Disabilities Act (ADA)

Submitted by mmaliha on Thu, 09/13/2018 - 10:27

The Americans with Disabilities Act (ADA) of 1990 makes it illegal for discrimination against disabled people for purposes of service or employment. The ADA defines protected disabilities as those that substantially restricts/limits one or more of the major life activities of an individual. How does one define "major life activities"? According to the US Equal Opportunity and Employment Commission, these activities include hearing, seeing, speaking, walking, breathing, caring for oneself, learning or working. But one type of activity might be more substantial/major to one person than another type. How does the ADA account for these subjective preferences in their rules? It is also stated that an employer does not have to provide reasonable accommodations if it imposes an "undue hardship" (significant difficulty or expense relative to employer's size, financial resources, and nature of operation). Does this not hinge upon civil rights of disabled persons seeking employment? Though if we consider it the other way, not allowing businesses to make reasonable choices for their profit might be infringing on their own corporate rights.

Homework draft

Submitted by cdkelly on Thu, 09/13/2018 - 02:45

The primary difference between research and review articles is that research articles describe a particular project and all of the involved components. Whereas review articles describe an entire area of research and all of the relevant studies working toward a similar goal. The research article has the level 1 headings summary, introduction, methods and materials, results and discussion. It also contains level 2 headings in the methods and results, both covering specific parts of their respective sections. In the review article, the level one headings include an abstract, an introduction, sections for myrmecomorphy, myrmecophily, and myrmecophagy, as well as a brief discussion at the end. Like the research article, it also has level 2 headings.

I found it interesting that the review article contained more level 2 headings, but it makes sense since the review is drawing from so many different sources. Also, the writing style of the review came off as more digestible because it was meant to describe a more broad topic.

Glioblastoma background research

Submitted by cdkelly on Wed, 09/12/2018 - 23:38

    Much like other solid tumors, GBM tumorigenesis leads to oxygen deprivation of specific regions and consequently hypoxia. This lack of oxygen tension in critical areas causes the expression of hypoxia-inducible factor 1 (HIF-1), which then causes the overexpression of VEGF. The resultant ligand binds to growth factor receptors on cancerous endothelial cells and induces angiogenesis (Vleeschouwer, 2016). This is an interesting component of cancers in general because the hypoxic areas that come from this process normally lead to cell death, but CSCs, specifically in GBM, thrive under these conditions due to the aforementioned mechanisms of angiogenesis.

There are currently two theories that aim to explain the heterogeneity of GBM solid tumors and the like: the stochastic model and the hierarchy model. The stochastic model posits that the heterogeneity of tumor cells results from both intrinsic and extrinsic factors affecting cells with the same mutations. On the other hand, the hierarchy model takes a more nuanced approach by suggesting that only a few CSCs can initiate growth of a tumor, and the heterogeneity of the GBM tumor cells arises from the related cells being at different points in development/differentiation. This model points to the small subset of CSCs being the root of cancerous growth, resistance, and recurrence (Vleeschouwer, 2016). The issue then becomes identifying the cancer stem cells

Interest in Geomorphology Course

Submitted by lmikaelian on Wed, 09/12/2018 - 22:06

My interests lie in environmental microbiology and astrobiology. I’ve taken a few of [REDACTED]'s microbiology courses, including his summer field course, [REDACTED]. Many of my class projects in his classes and during my summer research, I worked with samples collected from sites from Inyo County, California, including at Deep Springs Lake and the hot springs at Little Hot Creek. I’m interested in these areas because of the growing body of literature coming out of NASA’s Jet Propulsion Laboratory and other researchers publishing in the field of astrobiology. These researchers are looking at hot springs here on Earth—in Inyo County’s hot springs and in Yellowstone National Park—as in situ models for what life on Mars may have looked like millions of years ago. One study published in May this year—while we were on the field course—examined evidence of microbial respiration preserved in mineralized microbial mats. The authors of the study suggested that we may find similar-looking fossils on Mars. Of course, it’s hard for astrobiologists to get close enough to find fossils like these on another celestial body. Until we have the resources to send manned missions to other bodies like Mars, Saturn’s moon Enceladus, or Jupiter’s moon Europa, etc., we can observe them from afar and identify geophysical features—namely, liquid water—that indicate a hospitable environment.

I’ve built up experience in environmental microbiology through [REDACTED]’s classes, as well as a soil microbiology course I’m currently taking. I’ve also taken other environmental science courses, such as [REDACTED]'s biogeochemistry course. I think that geomorphology is probably a key subject for me to build up my knowledge in. Being able to identify the geological features that astrobiologists look for, like surface or subsurface water or evidence of such, historic glaciers, vulcanism, tidal heating, etc., understanding why astrobiologists may look for these things, would be very useful to me in the future.

Literature draft

Submitted by msalvucci on Wed, 09/12/2018 - 21:18

Throughout reading the two articles, I noticed many differences in the style and structure of the writing. The review paper began with an abstract explaining the objectives of this paper; this surprised me because I assumed that a summary of a review paper would sound redundant. However, it is helpful to start the paper with an abstract to prepare the reader for the extensive information regarding spider-ant associations that follows. After the abstract was a heading for the introduction, and this began with a number. The number system for paragraphs is useful as it helps the reader identify the paragraphs and sub-paragraph topics. As for the research article, the abstract was instead named the summary, which provided similar information regarding the journal. The introduction and proceeding paragraphs were not numbered, but instead stated as ‘materials and methods’ and ‘results’. This was different than the review article, but just as easy to understand. I did note that the introduction for the research paper was significantly longer than the introduction of the review paper. 

Love Conquers All Draft

Submitted by curbano on Wed, 09/12/2018 - 21:11

It is debatable whether or not the quote “love conquers all” is true or not. In some ways, I believe that the statement is true. In other ways, I completely disagree with the quote. The quote itself is very broad and vague, so it is hard to make a full conclusion. There are many types of loves in life. Humans can love one another, whether it is in a romantic, platonic, or somewhere in between. Furthermore, we can love things, such as cars or power. While I do believe love is a powerful force, sometimes love is not enough. Love drives us to do many things in life, whether it is good or bad. However, if love is leading us to do something bad, can we still consider it love? When people are passionate about or love something, they often will sacrifice anything for what they love. In the end, however, I believe that when people love one another and join forces for a single cause or thing they love, it can change the world. I think that is one way that “love conquers all.” We often see the idea of “love conquers all” portrayed in movies and books. For example, Disney often glorifies the idea and power of romantic love. The glorification of love can be misleading and dangerous. While love can be healthy and beautiful, there is also abusive and toxic love.

NaCl solution concentrations on the germination Phaseolus vulgaris

Submitted by angelasalaza on Wed, 09/12/2018 - 21:09

The experiment was performed to determine whether salt concentrations directly affected with the bean’s germination and root length. The beans were placed into different solutions of  NaCl concentration. The control group of the experiment, Set one had been diluted with a solution of 0% NaCl, to determine whether salt had any effect on the other beans different bags labeled two through seven were watered with different sodium chloride concentrations. As the concentrations of NaCl increased the percentages of germination decreased along with root length, set two 0.025% NaCl  solution had the highest root growth 8.5 cm. Due to NaCl concentration increase all bean germination after the third experiment the third roots showed lower percent of germination decreasing from by 90% to 0%. Different to the first three sets of lower concentrations of NaCl solutions the beans that did germinate produced shoots in lesser lengths 0.05% 6 cm, 0.1% 7.5 cm, 0.5% 5.6 cm, 1.0% 4.7 cm, 2.5% 0cm, 5.0% ocm. The beans that did not germinate enabled a mold at sprouting phase.  The experiment did show that increasing the NaCl solution would affect bean germination because increased NaCl concentrate prevented shoot growth .

Melting Point Experiment Discussion

Submitted by bthoole on Wed, 09/12/2018 - 19:17

The purpose of this lab was to learn how to accurately determine melting points and to use this technique to then determine the melting points of two unkowns. The melting point is a physical property of a solid which can be used to help identify a substance. Usually, a solid will not melt at a specific temperature but instead will melt over a range. When using a melting point range, a narrow range suggests that the compound is relatively pure, whereas a larger range suggests a relative impurity. For this lab, a range of 2 degrees celsius was considered narrow and pure, with any greater range resulting in a retest with a new sample. 

In this lab, the melting points of two unkowns and the three compounds naphthalene, urea and sulfanilamide were to be determined. By using the melting temperature device it was possible to quickly heat the known compounds to 10 degrees celsius below their given melting point range. From there, the heat could ramp up at about 1 degree celsius per minute so that the melting could be observed when it started and when it finished, thus providing a range. 

The observed melting range for naphthalene was 81-83. The narrow range suggests a level of purity for the sample. The expected range was 79-80. The observed result was slightly higher than the given melting point range , but this could stem from the mel-Temp device thermometer being slightly off, or due to the purity of the sample. The observed melting range for urea was 133-135. Again, the narrow 2 degree range suggests the purity of the substance tested. However, here too the observed melting temperature range was slightly different than the given 132-134 range. Here, the difference is by 1 degree and does not suggest any larger error at play. The temperature range difference was slight and could be applicable to the thermometer device. The last given compound was sulfanilamide and it had an observed melting point range fo 165-167. This is the same range that was given for the known compound and fits within the 2 degree temperature range, suggesting that it is relatively pure.


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