It can be argued that almost all diseases have, at their root, a cellular basis. This means we can typically trace every genetic or acquired condition to a problem in a specific type of cell. Is it possible, however, that these diseases/conditions/traits can actually be traced as far as the organelle level? Explore this possibility.

Considerable effort has been directed toward determining the genes in which sequence variation contributes to the development of type 2 diabetes, a disease that results from a loss of sensitivity of cells to insulin. Approximately 800 genes have been implicated. Explain the significance of the observation.

DCMU is marketed as an algicide and an herbicide. It works by blocking the binding site for plastoquinone on photosystem II.

1. If DCMU blocks plastoquinone from binding to photosystem II then in what state (oxidized or reduced) will the chlorophyll a of photosystem II be stuck? Why?
2. Based on your answer above, in what state would plastoquinone be stuck? Why?
3. Considering where DCMU binds, would plants in nature exposed to DCMU be able to produce

ATP and NADPH through the light reactions? Why or why not?

4. If plants exposed to DCMU cannot produce ATP and NADPH through the light reactions, how

would this affect the light-independent reactions?

5. DCMU, as an herbicide, will eventually kill plants that are exposed to it. Why is this the case? In

answering this, relate DCMU to photosynthesis and both DCMU and photosynthesis to cellular respiration.

2. The hydrolysis of ATP is the cell’s most commonly used exergonic reaction when performing energy coupling. Explain energy coupling, why it is necessary, and how the hydrolysis of ATP fits into the process. Use vocabulary words such as “endergonic,” “exergonic,” “spontaneous,” and “nonspontaneous.” (8 points)

4. Prokaryotic organisms do not have membrane-bound organelles. However, they are able to make ATP and survive.

   1. Assuming that bacteria cannot use their membranes to make ATP, which process can they still use in order to generate ATP? (2 points)

   2. Why can they perform this process even though they lack membrane-bound organelles?

      (2 points)

. 1. Explain Hamilton’s Rule in words.

2. Relate indirect fitness and kin selection to the alarm callings of black tailed prairie dogs.

4. Does kin selection explain how humans distribute wealth? (You don’t have to write about this, but what about something like the Bill and Melinda Gates Foundation? Think about how you’d explain that.)

Energetics and Metabolism Activity

Humans are described in a couple of different ways in relation to maintaining body temperature: homeotherm and endotherm are two common phrases. “Homeotherm” translates to “same temperature,” meaning humans maintain a stable body temperature regardless of the external environment. Related is the term “endotherm,” meaning “internal body temperature.” Humans, being warm-blooded, are dependent and capable of internally generating heat when needed. Regardless of the phrase used, the ability to maintain a stable body temperature is a critical part of our homeostasis. Therefore, we expend a lot of energy to maintain a near-constant internal environment of 37°C, which is largely accomplished by our metabolism.

Other organisms are poikilotherms or ectotherms; they cannot internally regulate their body temperature, and their body temperature can change depending on the external environment. Most fish, sharks, reptiles and amphibians fall into this category. While ectothermy is a significant energy-saving adaptation, it also means an organism’s metabolic rate is dependent upon the external environment. Higher temperatures increase metabolic rate, colder temperatures slow it down.  

In this activity, you will be examining the effects increased temperature has on the metabolic rates of three species of fish.

Go to the following website, and perform the experiment:

http://www.glencoe.com/sites/common_assets/science/virtual_labs/CT08/CT08.html

Fill in the table below with your results:

1. Interpret your results from the experiment; what do these data tell you about fish metabolic rate in response to temperature?

2. How might ectotherms have to compensate for their variability in metabolic rate in terms of how much they eat?

3. Compare and contrast the basal metabolic rate of a fish and a human. How are each maintained? How might the BMR of each change in a warm environment? A cold environment?

The plasma membrane is a structure common to all cell types and important in providing the cell with selective permeability. Identify one way that certain organisms can change the construction of their plasma membrane given changing environmental conditions (beside  biochemistry)

Linda has asked Brenn to prepare a 1% agarose gel for a gel electrophoresis analysis. But before he could do that, he needs to prepare 600 ml of 1x TAE from 95x TAE. How much 95x TAE and water should he add to create the 1x TAE solution? Afterwards, how much agarose does he need to weigh out, in grams, and add into 50 ml of 1x TAE?

Imagine a student measures the concentration of a bacterial culture using the "direct microscopic method" (using a hemocytometer) and by "using turbidity to count cells in liquid culture." Based on their calculations, there were 10,000 total cells/mL and the viability of the culture was 90%. Which method allowed the student to determine viability and why/how?

What is the role of news media in a democracy? How is quality journalism compromised by media conglomeration?

Is this a good answer? Would you add anything to it? Thank you

2) Autoimmune polyendocrinopathy ectodermal dystrophy (APECED) is a combined autoimmune/immunodeficiency disorder triggered by defects in expression of the gene AIRE (for the autoimmune regulator). AIRE expression is believed to allow for the production of a ‘shadow self’ within the thymus, allowing for multiple tissue-specific antigens (e.g. insulin from the pancreas, or gonadotropin-releasing hormone from the hypothalamus) to be expressed at very low levels by thymic stromal cells. Thus, AIRE expression strongly correlates with the principle of ‘central tolerance’ whereby autoreactive T cells are deleted by negative self-selection in the thymus.

Read up on APECED, and pick two of the syndrome’s immunological problems. Explain or hypothesize how these defects arise from a failure of AIRE expression.  

(10 points, 5 points per condition)

Answer:

APECED or autoimmune polyendocrinopathy ectodermal dystrophy is an autoimmune disease that is caused by a defect in the AIRE protein. Under the normal functioning of the body, many T cells are produced which may react negatively with the antigens of the body itself, thus disrupting many important and core functions required for the normal functioning of the body (Gregory & Lionakis, 2019). The AIRE protein functions to identify and subdue these antibodies, and in case of any defect of AIRE, these T cells subsequently produced will cause autoimmune diseases.

Usually, in case the AIRE protein is malfunctioning, the effects in the form of autoimmune diseases are usually visible by early childhood. There are several diseases pertaining to this condition, three of the main ones are described as follows:

1. Chronic mucocutaneous candidiasis
2. Hypo para thyroidism
3. Adrenal gland insufficiency

At least two of the three aforementioned conditions must be present in a person at a given moment, who is suffering from some autoimmune disease.

Chronic mucocutaneous candidiasis

This is the first problem that usually appears when you happen to suffer from APECED. Its symptoms include infections on nails, mouth and basically anywhere else with a mucosal lining. These moist areas are usually attacked by the fungi of the candida family (e.g.: Candida Albicans) and these are called yeast infections that are more than often of severe and chronic nature. The person suffering often suffers from an infection in the oral cavity, esophagus and in cases of women, the vaginal cavity as well.

Hypo para thyroidism

The parathyroid glands are secreting hormones, mainly the parathyroid hormone that regulates calcium and phosphorus. The deficiency caused will lead to a tingling sensation in lips, muscle cramps, weakness, and fatigue as well. the severe cases will see muscular spasms and respiratory collapse.

Adrenal gland insufficiency

The adrenal glands are usually heavily effected and therefore will case several metabolic deficiencies in the body. Loss of appetite, short stature, yellowing of the skin, weight loss and slow blood pressure as well.

The hypothesis of how AIRE dysfunctionality occurs and its relation to the conditions above:

1. The first and foremost reason for the unavailability of AIRE, to help the normal functioning of the immune system is obviously a mutation in its genetic background. AIRE has its genes at position 22.3 on the long (q) arm of chromosome 21 with the exact co-ordinates of Cytogenetic Location: 21q22.3. an aberration in base pairs will definitely cause malfunctioning of sorts (reference, 2020).

Autoimmune polyglandular failure type 1 (APS1), is a recessive form of hypoparathyroidism which in turn is unvaryingly caused by Mutations of the autoimmune regulator gene (AIRE) gene this is also called autoimmune polyendocrinopathy candidiasis ectodermal dystrophy (APECED), which we have discussed in detail before (Ergun-Longmire & Maclaren, 2016).

Question 1. Cystic Fibrosis (CF) is an example of a protein mis-folding disorder since most of the mutations associated with CF lead to the improper folding and processing of the plasma membrane-localized Cystic Fibrosis Transmembrane Conductance Regulator ion channel (CFTR).

The CFTR protein initially enters the endomembrane system through the process of co-translational translocation into the endoplasmic reticulum (ER) and is inserted as a Type IV membrane protein. N-linked glycosylation of the CFTR protein then takes place in the ER and continues in the Golgi.

Name the four types of sequence signals in the CFTR protein required for its proper targeting and processing up to this point (the Golgi) and give an explanation for each.

Is this a good answer? Would you add anything to it? Thank you

1) Scientists have observed temporary suppression of B cell development in bone marrow during infection with a number of viruses, including hepatitis A, B, and C, influenza, and parvovirus B19.

Given what you know about B cell development, provide 2 hypotheses to explain this phenomenon, one focusing on why the host might suppress B cell development, and the other focusing on why the virus might do this.  

Also, hypothesize why this sort of development suppression is seen with viral infections, but not with bacterial infections, even very severe bacterial blood infections.

(9 points, 3 per hypothesis)

Answer:

A Suppression of the immune system after contaminations or aggravation is a significant procedure that limits immune-mediated pathogenesis and autoimmunity. A few components of immune concealment have gotten a lot of consideration in the previous three decades. These incorporate components identified with suppressive cytokines, and changing development factor (TGF)- β and interleukin (IL)- 10, delivered by administrative cells, and instruments identified with apoptosis mediated by death-ligand

The immune system contains a huge swath of cell types and effectors specific to identify and demolish pathogenic microorganisms and the cells and tissues that harbor them. With this exceptionally lethal defensive capacity comes the requirement for tight guidelines so that once the risk of disease has passed, the system can come back to relative quiet and further harm can be stayed away from. This guideline is mediated by subsets of cells and immunosuppressive particles that are particular to effectively stifle the immune reaction. In a perfect world, immune concealment adjusts the ruinous powers of aggravation while permitting leeway of pathogenic irresistible operators.

General hypothesis why bacteria don’t factor the same response

The bacteria do not have the necessary DNA/RNA controlling abilities as our usually attributed to the viruses. The viruses have the ability to genetically alter the immunity of the victim that they attack, therefore, their effects are long-lasting and are often shown by the triggered immunodeficiency responses (Lundy, 2012). Bacterial infections do not have these characteristics.

Second Hypothesis

Viruses are obligate intracellular parasites. They are wired to take control of the biological machinery of the host. In this regard, it makes sense that their method of infecting is fundamentally different from those of bacterial infections. The bacteria are complete organisms in of themselves, whereas viruses are just proteins or genetic material encased in some protein covering (Laffin, 2001). This difference in their physiology explains why bacterial and viral infections are fundamentally different in their approaches.

Third Hypothesis

The third hypothesis answers the given question, in light of a different perspective. Viral-bacterial co-existence has been known to present for quite some time. Recently, it has been researched extensively, to see if it has any medically useful implications (Almand, Moore, & Jaykus, 2017). But we can take such an example, in order to see how bacteria and viruses are completely different entities and how they work in different spheres altogether. The viruses might even overtake the bacteria to get its own way into the cells of the host. These types of interactions show us the difference in viral and bacterial mechanisms.

How does each molecule of NADH generate 2.5 ATPs after electron transport and oxidative phosphorylation?

Why does FADH2 only generate 1.5?

Isle Royale SimBio lab model:

You have accepted a position with the U.S. Fish and Wildlife Service. You are asked to advise the U.S. Park Service on likely future population fluctuations in wolf and moose populations on Isle Royale. National Park Service policy is not to intervene in natural ecological processes unless absolutely necessary.

a) Based on your understanding of current ecological concepts, especially the importance of numerical and functional responses of wolves and moose (Krebs, pages 222-223) as well as both direct and indirect species interactions, list three alternatives for the Park Service regarding how to manage the predator population that is currently threatened by local extinction on Isle Royale. What sources did you use in developing your alternative suggestions?

b) Explain which of the three alternatives you would select if you were the Park Superintendent.