Writing in Biology

With 6 million square kilometers of forest that house “approximately 10% of the world’s biodiversity and 15% of its freshwater”, the Amazon is the world’s largest tropical rainforest. It is more biodiverse than any other single area on the planet, and it is here that some of Earth’s strangest creatures live. Part of the reason for the rainforest’s extensive diversity is the year-round rainfall which gives the forest its name. There is also relatively low variability in temperature throughout the year, which means the Amazon is not a traditional seasonal forest; instead, it has a wet season and a dry season. The entire Amazon Basin gets at least 2000mm of rain annually, with the majority of this rainfall occurring during the wet season. In the central Amazon, the wet season starts around December, controlled by monsoon winds and the Intertropical Convergence Zone (ITCZ), which is a belt of trade winds that converge around the equator and shift north or south as the seasons change. In the southern Amazon though, the rainy season starts in mid-October— approximately two months before the monsoon winds and the ITCZ bring the storms—because of increased transpiration during the dry season. 

The ability to control enzyme activity is essential in cells in order to produce molecules when needed and to conserve energy/resources. One way to regulate enzymes is through activators and inhibitors. These molecules alter the enzyme's conformation or block the active site, but they are not involved in the reaction in any way. Enzymes can also be regulated through covalent modification by phosphorylation. The reversible addition of a phosphate group alters the conformation of the enzyme, increasing or decreasing its activity by affecting substrate binding and/or its ability to produce products. In phosphorylation, kinases add phosphate groups while phosphatases remove them. Another form of enzyme regulation is the cleavage of an inactive enzyme, where catalytically inactive precursors are cut to create the active enzyme. The activation of chymotrypsinogen to alpha-chymotrypsin is an example of this.

Irreversible inhibitors also regulate enzymes by permanently impairing enzyme activity, typically via covalent modification. Irreversible inhibitor usually, but not always, result in the complete loss of enzyme activity. On the other hand, reversible inhibitors are not permanent, and they come in three forms: competitive, uncompetitive, and noncompetitive/mixed. Competitive inhibitors bind to the active site and prevent substrate binding while uncompetitive inhibitors only bind to the enzyme-substrate complex at a location other than the active site; however, noncompetitive/mixed inhibitors are able to bind to the free enzyme and the enzyme-substrate complex at a location other than the active site, although not at the same time.

The ability to control enzyme activity is essential in cels in order to produce molecules when needed and conserve energy/resources. One way to reulate enzymes is through activators and inhibitors. These are molecules that alter the enzyme's conformation or block the active site, and they are not involved in the reaction in any way. Heteroallosteric effectors are molecules that interact with allosteric enzymes and alter their activity. Enzymes can also be regulated through covalent modification by phosphorylation. The reversible addition of a phosphate group alters the conformation of the enzyme, increasing or decreasing activity by affecting substrate binding and/or ability to produce products. Kinases are proteins that add phosphate groups, and phosphatases are proteins that remove phosphate groups. The cleavage of an inactive enzyme is another form of regulation. Catalytically inactive precursors are cut to create the active enzyme. The activation of chymotrypsinogen to alpha-chymotrypsin is an example of this. Another form of enzyme regulation is through irreversible inhibitors. These molecules permanently impair enzyme activity, typically via covalent modification. Irreversible inhibitor usually, but not always, result in the complete loss of enzyme activity. On the other hand, reversible inhibitors are not permanent, and they come in three forms: competitive, uncompetitive, and noncompetitive/mixed. Competitive inhibitors bind to the active site and prevent substrate binding, but uncompetitive inhibitors only bind to the enzyme-substrate complex at a location other than the active site. Noncompetitive/mixed inhibitors are able to bind to the free enyme and the enzyme-subtrate complex at a location other than the active site, but not at the same time. 

Ethanol (4.0 mL) and benzoin (0.5004 g) were added to an 25 mL Erlenmeyer flask. The flask was first swirled at room temperature for the solutes to dissolve. Some heat was also added to facilitate the dissolving. Once completely dissolved, sodium borohydride (NaBH4) (0.102 g) was added with a microspatula over the course of several minutes. After, the mixture was swirled for 20 minutes at room temperature. 5 mL of water and 0.3 mL of 6M hydrochloric acid were added to the flask after being cooled in an ice bath. 2.5 mL of water was then added to quench the solution. 1,2-diphenylethane-1,2 diol was collected with the vacuum filtration and rinsed with ice cold water.  The product was left to dry for 15 minutes on the filter. Once the product was weighed, the crude yield mass was determined of 0.512 g. The crude product was then recrystallized with 1.5 mL of acetone. Once the crystals were dry, the melting point of the purified 1,2-diphenylethane-1,2 diol was measured to be 137 degrees celsius and the percent yield and mass yield were.

Mnemiopsis were jellyfish released into the Black Sea while the Black Sea was already facing problems due to increased inputs of nutrients. Eutrophication is an increase in the nutrient content of an ecosystem. Mnemiopsis increased rapidly causing zooplankton to decrease, phytoplankton to increase, oxygen concentrations to decrease, fish to decrease. Populations can change from birth, death, immigration, and emigration. Population dynamics are how populations change in abundance overtime. Population fluctuations are how the population changes in size, abundance, and numbers. Populations rise and fall about the mean. Population outbreak is when populations are exploding in numbers. Population cycles are alternating periods of high and low abundance occur after constant intervals of time. They may be caused by Internal factors (hormones or behavioral changes) or external factors (weather, food, predators).

Hypothyroidism is a condition in which the thyroid gland doesn't produce enough thyroid hormone. Hypothyroidism may not be noticable in the beginning however, if left untreated could cause a numerous amount of health issues including; joint pain, obesity and heart disease. The symptoms of hypothyroidism vary depending on the severity in the lack of hormones. Some common symptoms include; weight gain, fatigue, and increased sensitivity to cold. Most of the causes that are related to hypothyroidism are due to autoimmune disease. Autoimmune disease is when your immune system begins to produce antibodies that attack ones own tissues. Hypothyroidism like other autoimminue diseases is not ideal and is not something an individual wants to live with as there are medications that must be taken to produce a sufficient amount of thyroid hormone. 

Genome editing has potential to eliminate or minimize deadly diseases in the human genome. It has been popularly used among agricultural scientists, for genetically-modified organisms, and those specialized in infectious diseases and epigenetics (Petherick 2015). Genome editing has been progressively trialed for treating single-gene diseases, such as cystic fibrosis and sickle cell disease (Hsu et al. 2015). Germline editing could knock out a disease not only in the embryo in which it is being performed on, but also eliminate the disease from future generations.  Human diseases such as HIV could potentially be eliminated from the human genome. Gene editing in conjunction with stem cells might make it possible to generate gametes for reproductive purposes and correct errors in their genome. This would minimize the need for oocyte donation (Sugarman 2015). Also the use of CRISPR/Cas9 is an efficient and inexpensive method for gene editing.

The debate about genome editing arises as the ethical issues are being exposed towards humans. Genome editing is a form of genetic engineering where DNA can be altered by insertion, deletion, or replacement to modify a targeting gene. One of the most common methods utilized for this desired effect is a CRISPR-Cas9 plasmid (Petherick 2015). This method is achieved by inserting the Cas9 and the CRISPR RNA (crRNA) to the target site on the genome, where Cas9 cuts the current DNA so crRNA can begin to create DNA in the target site. The created DNA leads to alterations in the genome, including insertions, deletions, and homologous recombinations (Zhao et al. 2014). This new tool has led researchers to believe that gene editing could potentially solve health problems linked to genes. Moreover, advancements in gene sequencing allow geneticists to accurately indicate which genes are causing gene-related health issues. However, insufficient studies prove that the mechanics of gene editing are safe and effective. Additionally, countries are banning research on gene editing for not only safety and ethical reasons, but because of potential gene edits that would be passed down to future generations. Regulations are currently being implemented for studies, and guidelines for human use regarding safety.

Male and female Blue Tits looks almost the same to the human eye but not to each other. The pulmage of both sexes includes strong ultraviolet, reflectance, which makes the birds more conpicuous to each other agianst the background colors of the woods in which they live. Males also have a brillant purple crown patch that we cannot see. The males display ultraviolet crown prominently during courtship, especially in the early morning light. Consistent with the process of sexual selection, females prefer males with brightest crown patches. They also pair assortatively: those with the brightest UV reflectance in their own plumage pair with the most brightly colored males.