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Perfect Paragraph - Urushiol 1

Submitted by kcapri on Fri, 04/21/2017 - 15:11

Poison ivy is a member of the Anacardiaceae family. Its members include cashews, sumac, and mangos, all of which contain urushiol as well (Aguilar-Ortigoza, 2003). Poison ivy’s history in North America dates back to the early 17th century, and possibly even before that. The first published records of poison ivy in North America date to 1609 in Captain John Smith’s writings about the New World after his voyage from England (Armstrong and Epstein, 2011).  Despite this fact, urushiol was first isolated quite recently in the 1920’s by a Japanese chemist named Rikou Majima (Boyd and Rucker, 2013). He named urushiol after the term urushi, the Japanese name for lacquer tree, due to its coloring. Urushiol is colorless until the allergen is exposed to oxygen in the air, and then turns a dark brown or black color - which gives it the same coloring as lacquer that is used for finishing wood (Boyd and Rucker, 2013).  

Plant Physiology - Discussion of Urushiol 3

Submitted by kcapri on Fri, 04/21/2017 - 15:09

Plants are impeccable chemists and it is critical to understand the chemical traits of urushiol before discussing synthesis. This toxin is a mixture of alkyl catechols that is comprised of a 1,2 dihydroxybenzene ring (Flank, 1986). It is a phenolic compound, which means it consists of a benzene ring with a long hydrophobic side chain consisting of a large number of carbons on the carbon-3 position of the benzene ring, as shown in Figure 2. Depending of the specific plant containing urushiol, the amount of carbons in the side chain differs. While poison ivy and sumac have 15 carbons on its chain, poison oak has 17 carbons.

Urushiol is synthesized in the secretory cells of the resin ducts by the shikimic acid pathway. Resin components are derived from carbohydrates that are produced from photosynthesis.  As shown from Figure 3, Protocatechuic acid is a product of the shikimic acid pathway and then used to produce urushiol (Caspi et al., 2013).

When discussing the amount or concentration of urushiol in plants, it does depend on the growth conditions and the particular season. A study performed by Japanese researchers indicated the percentage compositions of urushiol depending on its unsaturated bonds in Japanese, Korean, and Chinese Rhus vernicifera (lacquer trees). Researchers found that the most abundant urushiol was the triene urushiol at 71%, while the next most abundant was mono-urushiol at 14-16%, and diene urushiol at 5-8% concentration (Tetsuo et al., 2002).

Journal - Discussion of Urushiol 2

Submitted by kcapri on Fri, 04/21/2017 - 15:08

Urushiol is stored all throughout the poison ivy plant in the phloem tissue. It is present in the roots, stems, leaves, and fruits, but not in the pollen. The berries and flowers of the poison ivy plants have the highest concentration of urushiol (Bullock, 2011). This allergen specifically resides in resin ducts, which are specialized structures that are located in the secondary phloem. The resin ducts are lined with  secretory cells, where the urushiol is stored until damage is done to the plant and the resin ducts are ruptured. The function of theses ducts is to secrete a resin, or dilute solution of poison within a liquid medium, that will clog up the site of damage (McNair, 1918). The resin ducts leak out the contents in response to tissue damage of the plant, but the toxin is not a deterrent. It is a liquid bandage, similar to p-protein, that prevents water from leaking out (McNair, 1918). As shown from Figure 1, the epithelial cells form the inner wall of the resin duct, also known as the schizogenous cavity. When the cell walls of the plant split, the internal contents dissolve and the resin leaks into the cavity. To transport urushiol for release, the endoplasmic reticulum within the secretory cells transport the resin components into the intercellular storage space by passage through a porous cell wall into the resin duct (Vassilyev, 2000).

It is important to note urushiol storage in different seasons, as well as in different stages in the plant's life cycle - when death is upon it. Urushiol is stored in poison ivy all year round. It is less abundant in plants in the winter, but still present during this season. It is mostly stored and most potent in the spring and early summer (Reeves, 2000). Urushiol is unique in the sense that it is still stored in dead and dried plants from anywhere from one to five years (Reeves, 2000) . A study was conducted by Bedford Shelmire to test if poison ivy still contained urushiol after the plant was “killed” and damaged in different ways. He took pieces of these plants with urushiol and dried some pieces, crushed some, just washed some, and drowned some, and then tested if urushiol was still present and stored. He found that urushiol was still stored and potent after a year and a half in most cases (Shelmire, 1941).

Journal - Discussion of Urushiol 1

Submitted by kcapri on Fri, 04/21/2017 - 15:07

    Throughout our semester of studying plant physiology, most of the class covered processes of normal plant functions that involved anything from development, growth, and reproduction. These processes are complex and directly involve numerous elements and compounds from the environment that are modified and used in intrinsic metabolic systems. These compounds are called primary metabolites. These metabolites can be anything from sucrose to ethanol to lactic acid to cellulose, and can serve vital purposes in the world -- such as in agriculture by providing the populations with fuel, food, and fiber.

In addition to primary metabolites, secondary metabolites are also present in our world. They function differently than primary metabolites in the way that they are produced through modification of primary metabolite synthases and are not required for the functioning of a plant ("Primary and Secondary Metabolites,” 2015). Yet, they can also serve important roles in plant ecosystems, such as attracting pollinators, giving a plant its color, or even defense against predators. Secondary metabolites,  such as opioids, antibiotics, growth factors, and pigments, can aid in human uses, or they can serve as nasty reminders - such as urushiol, the allergenic component of poison ivy. Urushiol is a secondary metabolite of great interest due to its storage, synthesis, and release, as well as its human and environmental impacts.

Poison ivy is a member of the Anacardiaceae family. Its members include cashews, sumac, and mangos, all of which contain urushiol as well (Aguilar-Ortigoza, 2003). Poison ivy’s history in North America dates back to the early 17th century, and possibly even before that. The first published records of poison ivy in North America date to 1609 in Captain John Smith’s writings about the New World after his voyage from England (Armstrong and Epstein, 2011).  Despite this fact, urushiol was first isolated quite recently in the 1920’s by a Japanese chemist named Rikou Majima (Boyd and Rucker, 2013). He named urushiol after the term urushi, the Japanese name for lacquer tree, due to its coloring. Urushiol is colorless until the allergen is exposed to oxygen in the air, and then turns a dark brown or black color - which gives it the same coloring as lacquer that is used for finishing wood (Boyd and Rucker, 2013).  

Discussion of Red Hair

Submitted by kcapri on Fri, 04/07/2017 - 10:56

Less than two percent of people in the world have red hair, yet its uniqueness can be explained. Red hair is a recessive trait that is caused by mutations in the melanocortin 1 reception (MC1R). THis is a gene on chromosome 16. Since it is recessive, it has to be inherited from both parents in order to receive red hair. This results in more peole having the mutation as heterozygotes with one recessive, thus carriers of red hair, than there is people that are actually red-headed. In Scotland, 13% of the population has red hair while 40% carry the red hair mutation.

 

Image 1. Photograph depicting red hair traits. Taken from Matrix.

 

There can be different shades of red hair as well. The shade of the hair depends an other mutation regulating the pigmentation of the skin and hair. Skin and hair pigmentation is determined by eumelanin and pheomelanin. Pheomelanin has a pink to red hue nd is present in lips. The mutations in the MC1R gene causes more pheomelanin than just in the lips and results in red hair, fair skin, and freckles.

 

SOURCE:

http://www.eupedia.com/genetics/origins_of_red_hair.shtml

 

Perfect Paragraph - Rainforest

Submitted by kcapri on Fri, 04/07/2017 - 10:18

A rainforest is different than just a forest because it is a specific category of a forest. A forest is a rainforest if it has a large amount of rainfall each year (around 123 - 660 cm). It also must have humid or hot weather. Less than 10 percent of Earth is a rainforest, yet they are home to more than half of the unique flora and fauna in the world. Many rainforest have rare plants and animals.

Discussion of Forests & Rainforests

Submitted by kcapri on Fri, 04/07/2017 - 10:16

A forest is a habitat or ecosystem with a large populations of trees. Yet, there are often more than just trees in a forest. There are populations of birds, salamanders, insects, bears, and more organisms that exist in a forest. There are many classifications of forests, such as distinguishing them through dominance and variation of trees, differing climates, of differing species. Some types of forests include the taiga, temperate hardwood, tropical dry forest, and the rainforest.

 

A rainforest is different than just a forest because it is a specific category of a forest. A forest is a rainforest if it has a large amount of rainfall each year (1750-2000m). It also has humid or hot weather. Less than 10 percent of Earth is a rainforest, yt they are home to more than half of the unique flora and fauna in the world. Many rainforest have rare pants and extent animals.

 

El Yunque is an example of a rainforest. It is actually the only tropical rainforest in the United States. It is over 29,000 acres and is located on the island of Puerto Rico. It may be one of the smallest rainforest, yet does house a large amount of species diversity.

 

 

SOURCES:

http://www.brighthub.com/environment/science-environmental/articles/72604.aspx

https://www.fs.usda.gov/main/elyunque/about-forest

 

Perfect Paragraph - Mongoose

Submitted by kcapri on Fri, 03/31/2017 - 11:52

Mongoose live in burrows and create tunnel systems. They are social creatures and usually live in colonies and travel and fight as a team. Mongoose are most active during the day, and sleep at night. They are carnivores and were not native to Puerto Rico, but were introduced there. The type of mongoose in Puerto Rico are the Small Indian Mongoose, Herpestes auropunctatus. This species is great at fighting snakes and often eats poisonous ones, such as cobras.

Research Proposal - Discussion Section

Submitted by kcapri on Fri, 03/31/2017 - 11:50

DISCUSSION

Since the methods has not been followed yet, we do not have definite results. Yet, we are able to assume different possibilities and interpretations of potential results. As stated above, results will be evaluated by counting the number of moss colonies on the each group’s petri dishes as well as evaluating the height of the growth of the moss colonies. The height of the moss colonies will be taken before the two weeks with a ruler, as well as after the two weeks.

    If the all of the moss strains grow better in the 21.4℃ growth chamber, then that will portray that moss need warmer environments to grow optimally. This will mean that photosynthesis is more efficient in warmer climates. If the moss strains grow better in the 11.2℃ growth chamber, then one can conclude that moss grows better in colder climates. This could be due to the fact that in cooler, wetter climates, CO2 is more soluble and fixed by rubisco, and therefore photosynthesis is more efficient in colder climates.

 

Research Proposal - Moss Experiment - Powerpoint

Submitted by kcapri on Fri, 03/31/2017 - 11:48

Introduction:

Goal:

  • Determine the effect of  temperature on the growth of moss  from four different moss types

  • From the data, optimal temperature for growth can be inferred for each moss type

  • The results of this experiment can also provide a better understanding of how global warming will affect specific species

 

Methods

  • Collections: Four different types of moss will be used: fern moss, rock cap moss, ceratodon moss, and sheet moss - found on UMass Amherst Campus.

  • Assignment - 8 groups - each group will be assigned one species of moss. Two groups will be doing the same moss species to ensure accuracy.

  • Groups will plate five sprouts of each type of moss on two agar petri dishes.

  • Each group will receive a petri dish that will be kept at 11.2℃ and 21.4℃ - in ISB Growth Chambers.

  • Watch growth for 2 weeks.

  • Timeline:

    • Experiment start: April 3rd

    • Experiment end: April 17th (2 weeks)

    • Data analyzed: April 28th

Discussion

  • Results will be collected by measuring the height of the moss on  April 3rd (the 1st day) and on April 17th (last day) for each petri dish.

  • To measure the height of the moss, each group will utilize a ruler and measure the moss in each petri dish in millimeters.

  • After gathering the measurements, each group will collaborate with the other group that worked on the same strain of moss to compare data.

  • Together, they will create a clustered column graph that compares the height before and after the two week period for each petri dish, displaying the effects of temperature on moss.

  • From the graph, the groups can conclude which temperature results in the greatest growth for their strain of moss.

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