Orgo Lab Esterification

Submitted by bthoole on Tue, 11/13/2018 - 21:06

In this lab, 1-propyl propionate was synthesized through the esterification of 1-propanol and propionic acid to get a percent yield of 19.81%. The product was assessed for smell and analyzed using IR spectroscopy. The smell of esters is usually something fruity and is a stark contrast to its alcohol and carboxylic acid components, which typically have an unpleasant odor. The carboxylic acid and alcohol are the reactants in the mixture, with the sulfuric acid serving as a catalyst. The reactants create an ester and water in a process known as Fischer esterification. This is a seemingly simple reaction where the carbon and hydroxyl group bond is broken in the carboxylic acid and a new bond is formed between that carbon on the carboxylic acid and the carbon chain bonded to the hydroxyl group on the alcohol. Protonation of the carbonyl carbon of the carboxylic acid makes it a better electrophile which undergoes 1,2 addition by the alcohol and a proton from the alcohol is transferred to a hydroxyl group. 1,2 elimination leads to a protonated ester before it is later deprotonated.

A better treatment for Tuberculosis PP

Submitted by yurigarcia on Tue, 11/13/2018 - 19:36

 

There might be a cure for tuberculosis with a short treatment that’s better than the traditional one we have now. Tuberculosis (TB) has been treated with antibiotics since the discovery of streptomycin since 1943. According to a published study in Nature Medicine almost ten million of patients with active tuberculosis are diagnosed every year, that could benefit from this new treatment. 

In a new analysis of the University of California in San Francisco (UCFS) suggests that a more accurate therapy might be more effective, when treating tuberculosis. Scientists of UCSE concurred that the past failures in finding a new treatment was due to patients being treated the same way, without knowing the stage of TB. In the new study, the patients were stratified into three categories of the disease such as, minimal, moderate and severe. During, the four months treatment it showed that the treatment was highly effective for 47% of the patients with the disease. However, the four months were not effective for patients who had moderate or severe TB. The study shows that a stratified medicine approach can be applied in a feasible way to achieve shorter treatment for many patients with TB. With this unique approach leads to a low treatment for patients with a more serious state of the disease, or excessive treatment for patients with the less advanced disease, as they receive their medications that could harm them.

 

A better treatment for Tuberculosis Draft

Submitted by yurigarcia on Tue, 11/13/2018 - 19:35

There might be a cure for tuberculosis with a short treatment that’s better than the traditional one we have now. Tuberculosis (TB) has been treated with antibiotics since the discovery of streptomycin since 1943. According to a published study in Nature Medicine almost ten million of patients with active tuberculosis are diagnosed every year, that could benefit from this new treatment. 

methods

Submitted by kruzzoli on Tue, 11/13/2018 - 16:21

We rewatched the videos and choose a 5 minute period and 10 behaviors that occurred in that time frame for a reliability analysis. One group member watched the 5 minutes worth of video and used Jwatcher to indicate the times at which each behavior took place. This member rewatched the same five minutes of video and used Jwatcher to indicate the times at which each behavior occurred a second time. The reliability was determined between the two data sets and we redid the indication of when each behavior occurred until the reliability was above 65%. A second group member watched the same 5 minutes of video and indicated when behaviors occurred using Jwatcher. This was redone until there was above a 65% reliability between the first and second group member.

Orgo Lab - Esterification Discussion Draft Part 2

Submitted by sbrownstein on Tue, 11/13/2018 - 11:26

The Infrared Spectroscopy (IR) that was created from the product produced two major peaks outside of the fingerprint region. One peak obtained two spikes, one at 2959.90 and the other at 2873.09. This peak resembles the C-H bonding on the product’s structure. The second peak outside of the fingerprint region occurred at 1739.87. This peak resembles the double bond between the carbon and oxygen atom in the product’s structure. Within the fingerprint region, there was one meaningful peak occurring at 1465. This peak resembles the C-C bonding within the product’s structure.

Cell molec draft 2

Submitted by curbano on Tue, 11/13/2018 - 11:26

While I have learned about the cell cycle many times in high school as well as college, I never realized how complex this cycle truly is. I was aware of checkpoints and the steps, but there are so many different "switches," mechanisms, and regulations to make sure cells going through replication come out normal. It amazes me that even though the cycle is so complex, for the most part, our cells and we come out fairly normal and function properly. I guess the many regulations prevent errors from occurring, but it still is amazing! I wasn’t sure what nucleating microtubules was or its purpose, so I looked it up. Microtubules nucleation is the process in which tubulin alpha-beta heterodimers begin aggregation to form an oligomeric tubulin structure, also known as a microtubule seed. The microtubule seed then eventually forms into a microtubule. This means that microtubule nucleation is the initiating step in the formation of a microtubule when there are no microtubules present.

PP

Submitted by curbano on Tue, 11/13/2018 - 11:25

In nearly every living species, temperature influences physiological and biological processes in the body. Spiders are ectothermic organisms, meaning they are unable to regulate their body temperatures relative to their environment. Because of this, changes in temperature can have a large impact on their metabolic rate and overall activity (Barghusen et al). It has been found that even winter active spiders will make less effective webs or no webs at all at temperatures 2° colder than the temperature they are accustomed to. Having a less effective, or no, web greatly reduced feeding, which could be detrimental for spiders (Aitchison 1984). Since web production is a large part of spider activity and survival, we decided to focus our project on how varying temperatures influence web production. Past research has found that spiders in lower temperatures tend to use less spiral silk than spiders in warmer temperatures (Vollrath et al). Our project focuses on how temperature influence the weight of webs.

 

Fish reproductive strategies

Submitted by mtracy on Tue, 11/13/2018 - 09:56

There are many reproductive strategies that fish use. For instance, many fish species reproduce through polygyny, where 1 male will have multiple partners. With this method, the female partners usually choose the territory, not the male. A male will determine and defend its territory and build nests which the females will visit or say in. This of course depends on how sutible the nest or territory is. Fish which are polyandrous have 1 female which reproduces with multiple males. An example of this is the anglerfish. The female in this species is very large. Males are tiny tadpole looking fish, which latch onto the female. Eventually these males become parasitic and literally fuse with the female, becoming a sort of male gonad on the female. This even goes so far as to share the same ciruclatory system. Whenever th female wants to reproduce, the male is signaled and sperm is released into the eggs, fertilizing them.

Microtubules

Submitted by bthoole on Mon, 11/12/2018 - 21:15

During the S and G2 phases of the cell cycle, along with the growth and DNA synthesis, part of the cell’s preparation for M-phase includes the duplication of centrosomes. Centrosomes are the microtubule organizing centers in cells and create the spindle poles during M-phase. Microtubules are protein fibers made of tubulin and along with actin and intermediate filaments, make up the cytoskeleton. Not all microtubules are the same and the differences give polarity and directionality to the fibers. They are made of subunits of alpha and beta tubulin. The microtubules extend from the spindle poles of the centrosomes on either side of the cell during M-phase and overlap in the center where other proteins hold them the overlapping units together, thereby stabilizing the spindle system. This utilizes kinetochore microtubules and interpolar microtubules. Meanwhile, the third type of microtubules, aster microtubules, connect to the cell cortex with other proteins.

Orgo Lab - Esterification Discussion Draft Part 1

Submitted by sbrownstein on Mon, 11/12/2018 - 17:52

In this lab, 3-methylbutyl propanoate was synthesized via a reflux of an 3-methyl-1-butanol and propanoic acid. The reflux was performed with the intention to remove the excess water from the solution. The product was weighed 1.12 g and obtained a sweet, banana/pineapple scent. The percent yield was 70.88%. Although this is a relatively high percent yield, it is not 100%. Some reasons as to why the percent yield was not as high as expected could be due to loss of product during transfers between glassware, not allowing the water to completely evaporate in the reflux reaction, or not thoroughly mixing my solutions before and after the reflux reaction. By not allowing the water to fully evaporate or not mixing the solution completely, impurities may have remained in the product, causing a low percent yield.

 

Pages

Subscribe to Writing in Biology RSS