Blogs

Polyandry is rare because in most cases natural selection has favored for females to be choosy and seek the best possible breeding opportunities because they have a greater parental investment and few expensive gametes, while males have many cheap gametes and are limited by access to females so they would achieve greater reproductive success if they reproduce with multiple females.

Extreme sexual displays and ornaments are found in species with promiscuous mating because they are subjected to strong sexual selection. This strong sexual selection is due to lots of variability in reproductive success, with a few males monopolizing reproduction, and a high cost for breeding successfully. (According to Bateman’s gradient, the steeper the slope the stronger the sexual selection).

On the Duty of Civil Disobedience by Henry David Thoreau explores a civilian’s duty to use their conscience, not pure legislation, to lead their actions.  Thoreau argues that the democracy of his time only makes legislation that grants the wishes of the majority by allowing them to decide what is right and what is wrong.  “Must the citizen ever for a moment, or in the least degree, resign his conscience to the legislator? Why has every man a conscience then?”. Thoreau then encourages men whose conscience finds certain laws unjust, to voice their disagreement through a number of ways.

Firstly, Thoreau warns men that they may be “treated as enemies” by the state for resisting the unjust laws at all.  He explains that the men deemed “good citizens” are the people who disregard their morals and act only in ways that serve the state, such as soldiers.  The Mexican- American war is a pressing issue during Thoreau’s time, causing him to point to soldiers as main proponents of unjust actions for the state. Thoreau compares these men to the worth of “wood and earth and stones” along with only commanding the same respect as “men of straw or a lump of dirt”.  Thoreau wants to prepare the men that will act justly for the resistance they will face on their journey. Although it may be more convenient to act with the majority, Thoreau believes that he cannot act this way “without disgrace...associated with it”. In this way, some people may be prone to follow the government instead of standing up for their rights.

Secondly, Thoreau warns the everyday citizen about the dangers of passivity. He says that he is not writing “On the Duty of Civil Disobedience” to Southern conservative politicians, but to the average people around him who “are more interested in commerce and agriculture than they are in humanity, and are not prepared to do justice to the slave and to Mexico, cost what it may”.  He argues that these people are more harmful to virtue than the few fighting against these virtuous ideas. These people wait for some other force to counter the state’s evil, when in reality, if they gathered their strength to fight for what they believe in, they could make a difference. “What is once well done is done forever”, although this quote is referring to a separate event, it is also applicable here.  If many people changed their attitude from passive to active, they could make a difference one time, and well, which would be done forever.

Like many systems and things in our bodies, many proteins work together to carry out certain functions. If one protein in a certain system or group is misfolded, it may cause a chain reaction of errors to appear in the entire system. Studying the interactions between certain proteins can help us better understand how certain interactions operate as well as think of ways to possible fix certain malfunctions. I think this sentence is trying to tell us that there is a variety of ways these complexes can come together. I don't think identical complexes work better or worse than different complexes, it just depends what the protein complex's function is overall. It's like when we look at subunits in quaternary proteins. Some subunits can be the same within the protein, while sometimes they are different. I think this sentence is trying to tell us that there is a variety of ways these complexes can come together. I don't think identical complexes work better or worse than different complexes, it just depends what the protein complex's function is overall. It's like when we look at subunits in quaternary proteins. Some subunits can be the same within the protein, while sometimes they are different.

A:

Figure 1 and 2 show the elephant seals production of offspring, female and male respectively.  The female seal( figure one) has a weak sexual selection and for this species it depends more on the male than female.  In figure 2 you can see that only very little males produce a lot and a little produce some and many produce very little to none.  Compared to the voles the male elephant seal has pretty similar data patterns to figures 3 and 4. The male elephant seal clearly has the strongest sexual selection.  Their ability to reproduce is based solely off of size and strength that is put in competition with one another during fights for the area that contains many fertile females. Figures 3 and 4 are similar to figure 2 in that it shows a gap from offspring around 10-15 off spring to around 35-40 offspring.  This is in both the vole figures and shows that not just one gender of the animal has all the strength in sexual selection but it is more base on each gender having better genes or being stronger or something, instead of elephant seals which have just the male fight over the females. In the vole species both genders compete for reproduction.

B:

OSR is defined as the ratio of sexually competing males to sexually competing females.  For elephant seals the OSR will definitely be above one as we discussed only males compete for sexual reproduction in the elephant seal species.  So there are more males than females competing meaning it must be greater than 1. For the vole species the OSR is harder to predict but should be less than one or equal to one.  This is because a relatively similar number of males and females compete for sexual reproduction in the vole species according to the data in figure 3 and 4. If not more females competing for sex in the species but it looks pretty close so it should be 1 or a little less than 1.

A gentle stream of air was passed over the solution, using the air flow hose in the fume hood, in the 25 mL Erlenmeyer flask to allow the liquid to evaporate. The flask was warmed with a hand until all of the solvent evaporated, and yellow solid remained. The solution was set to dry for 5 minutes.

During recrystallization, 1 mL of acetone was added for every 50 mg of yellow solid. The solution was allowed to cool to room temperature, then the solution was placed in an ice-water bath for an additional 15 minutes. The solution was filtered via vacuum filtration and the crystals were collected on a small Hirsch funnel. The funnel was lifted slightly to cover the crystals with 1 mL of ice-cold acetone, and the filter was placed back down to further vacuum filtration. Air was allowed to pass over the crystals for a few minutes and they were then scraped onto a tared piece of paper. The crystals were allowed to dry to a constant weight.  A small sample was saved to dry further and obtain a melting point.

During hydrolysis, 60 mg of the yellow solid, which is now identified as trimyristin, was weighed and transferred to a clean RB flask using a funnel. 2 mL of 6 M sodium hydroxide, 2 mL of 95% ethanol, and a few boiling chips were added and the solution was refluxed for 45 minutes on sand bath. The rest of the trimyristin was recrystallized a second time while the solution refluxed; allowing the solution to cool to room temperature for 10 minutes before cooling in the ice bath. A minimum amount of acetone was used to dissolve the crystals at the boiling point of the solution. The product was collected using vacuum filtration, and allowed to dry to a constant weight. The melting points of the once recrystallized solid and twice recrystallized solid were compared.

After hydrolysis, the flask was allowed to cool to room temperature. The contents were then poured into a 50 mL beaker containing 8 mL of water. Drop wise, 2 mL of hydrochloric acid were added as the solution was constantly stirred. The solution was filtered and the funnel was lifted 3 times to add very small portions of water (just enough to submerge all of the recovered crystals). The solid was allowed to dry overnight, and a melting point and % yield was taken.

Results:

Starting nutmeg mass: 1 g

Starting material(trimyristin): 0.473 g

After first recrystallization: 0.131 g  MP: 53-54 ℃

After second recrystallization: 0.80 g  MP: 54 ℃

Myristic acid mass:  0.046 g MP: 52-54 ℃

Myristic acid yield: 76.8%

Discussion:

The starting material nutmeg underwent multiple reactions in this lab and the final yield was calculated to be 76.8%.  This is the yield of Myristic acid from 60 mg of starting material after undergoing hydrolysis. Initially 1 g of nutmeg was started with to make .473 g of trimyristin, then a recrystallization was done and 0.131 g were recovered and the product had a melting point of 53-54 ℃.. The product of the second recrystallization had a mass of 0.080 g and had a melting point of 54 ℃. The MP were below the theoretical MP of trimyristin, which means the trimyristin created in this lab contained some impurities decreasing the melting point. Also the range of the MP is important, the higher MP range means the presence of more impurities. The myristic acid from hydrolysis had a mass of 0.046 g which is a percent yield of 76.8 %.  The melting point of the myristic acid was 53-54 ℃, which is very close to actual melting point which is 54.4 ℃. This means the myristic acid was very pure and was easily identified as myristic acid. The yield of the myristic acid and the trimyristin could have been decreased or affected by human error such as letting the mixture boil over and spilling. Other human errors may have contributed to lack of precision and overall error.

Post-Lab Questions

1. A saturated fatty acid is one where hydrogen atoms are attached at all maximum possible locations.  This means that each carbon to carbon bond is a single bond. A fatty with one double bond is a monosaturated fatty acid; a polysaturated fatty acid is one in which there is more than one double bond.  Trimyristin is all single carbon to carbon bonds, which would make it a saturated fatty acid.

2.  The old procedure differs from the new procedure in the fact that a lot of the ether soluble components in the nutmeg will remain in the acetone solution.  If the solution is cooled to room temperature before being put into the ice bath, they ether soluble components would be allowed to dissolve further before being put into the ice bath.

3. (1.8 g of tristearin)*(1 mol tristearin/891.48 g tristearin)*(3 mol stearic acid/1 mol tristearin)*(284.48 g stearic acid/1 mol stearic acid) = 1.723 g stearic acid

4. The mixture is a high boiling mixture.  The mixture needs to be refluxed. Reflux occurs when a mixture is heated at a high temperature for a certain amount of time, which allows vapor to be produced and cooled in a condenser dripping back into the round-bottomed flask.  This allows for a high separation.

5. If the mixture were heated at that temperature for 45 minutes, there would not be as high of a separation achieved from the reflux.  Heat speeds up a chemical reaction, if the solution were allowed to reflux at that temperature for a longer period of time, then the solution may achieve the chemical reaction that is wanted.

On the Duty of Civil Disobedience by Henry David Thoreau explores a civilian’s duty to use their conscience, not pure legislation, to lead their actions.  Thoreau argues that the democracy of his time only makes legislation that grants the wishes of the majority by allowing them to decide what is right and what is wrong.  “Must the citizen ever for a moment, or in the least degree, resign his conscience to the legislator? Why has every man a conscience then?”. Thoreau then encourages men whose conscience finds certain laws unjust, to voice their disagreement through a number of ways.

Firstly, Thoreau warns men that they may be “treated as enemies” by the state for resisting the unjust laws at all.  He explains that the men deemed “good citizens” are the people who disregard their morals and act only in ways that serve the state, such as soldiers.  The Mexican- American war is a pressing issue during Thoreau’s time, causing him to point to soldiers as main proponents of unjust actions for the state. Thoreau compares these men to the worth of “wood and earth and stones” along with only commanding the same respect as “men of straw or a lump of dirt”.  Thoreau wants to prepare the men that will act justly for the resistance they will face on their journey. Although it may be more convenient to act with the majority, Thoreau believes that he cannot act this way “without disgrace...associated with it”. In this way, some people may be prone to follow the government instead of standing up for their rights.

Protein is another macronutrient necessary to promote the health of the body. The body’s growth, repairing of cells,  and regulation of the body’s tissues and organs are all essential functions of the protein, therefore adequate amounts of protein in the diet is necessary to the optimal function of the body. My current food intake indicates a relatively steady amount of protein in my diet, at approximately 21 percent of the total calories I consume in one day. Overall, based on the two days of documenting my food intake, the main sources of protein are chicken, eggs, fish, and pork. The fish, unfortunately, was fried with batter, making a great source of protein that comes along with unnecessary amounts of fat, so in future meals I know to choose fish that’s steamed or cooked differently.The chicken is chicken breast and the pork was a lean piece of boneless pork chop, both relatively healthy options of protein, low in fat and sodium showing that the quality of the protein intake is quite well. Although those options of poultry and chicken are great, I could aim to expand my options and include beans, and nuts to obtain all the essential amino acids. Red meats, like beef, are excluded from being categorized as a healthy protein for it is much higher in saturated fats4. Harvard School of Public Health reported that the risk of dying from cardiovascular disease increased with increased consumptions of red meats, supported with evidence from a study that shows the risk of dying from cardiovascular increasing by 13 percent with every additional 3-ounce serving of red meat4.

Vitamin D is indicated to be lacking in my diet, for the target of 15 micrograms is not met for I only consume about 3 micrograms on average. Not getting enough vitamin D can be dangerous for it plays the role of modulating cell growth, neuromuscular and immune functions, absorption of calcium, therefore, contributing to bone growth. Deficiency not very uncommon because vitamin D is naturally not present in many foods, making it more important that we are aware of our intakes8. Given that we are entering the colder months it also is more challenging to obtain vitamin D from the sun, therefore it must be done by selecting proper foods. As mentioned before, fat-soluble vitamins are more likely to cause toxicity for it is stored in the body, therefore monitoring the intake of this vitamin is extremely important. In most extreme cases toxicity may raise blood levels of calcium, in turn leading to damage to the heart, blood vessels and kidneys8. Some of the best sources of Vitamin D are fatty fish, including salmon and tuna, both of which are foods I enjoy and will add to my diet in greater amounts to make up for the lack of Vitamin D in my diet. Beef liver, cheese, and egg yolks also contain some amounts of vitamin D.

This makes sense since most amino acids have no charge at all or very little charge. The less stable something is, the more energy it will use. The hydrophobic amino acids often are folded into the middle of the final protein structure to avoid instability. Chaperone cells are meant to assist with protein folding to make sure the protein folds into their correct shape. However, sometimes the up regulation or down regulation of these cells can cause the structure to not be folder properly. I'd expect to see more hydrophobic amino acids exposed when there's down regulation of chaperone cells. Is there an enzyme or drug that can be used to help control the regulation? From the reading, I took away that in the dominant-negative mechanism, the mutant protein is either dominant or co dominant to the wild type dominant protein. This causes the mutant protein to influence the function of the wild type dominant protein "negatively," or decreases its function. The mutant protein may completely take control over the dominant protein, or it may just decrease the dominant protein's activity. Proteins play a vital role in the way our bodies function and perform. After reading this article, it showed me how even a slight error or mutation can cause a lot of issues and cause diseases to form. Finding ways to help proteins conform to their proper shape can help cure many diseases. Understanding each level of protein structure is vital when finding cures to certain diseases and finding ways to manipulate protein shape to the correct conformation.