This website uses cookies to ensure you have the best experience. Learn more

Aquaporin 1 Essay

2018 words - 8 pages

Background

Most modern biology textbooks will tell you that low-molecular-weight molecules like CO2, NH3 (ammonia), and urea cross cell membranes by simple diffusion. Some scientists postulate, however, that specific pores mediate this transport. A recent study conducted to further this hypothesis examines expression of the water channel aquaporin-1 (AQP-1) and its enhancing affect on CO2 permeation into cells.

Why would scientists challenge the traditional simple diffusion theory? Two strong points of evidence led to this experiment:

First, many cell membranes have a very low permeability to small molecules: The outer membranes of some gastric glands allow very little CO2 to enter the cell, while most frog egg cells have membranes that act as virtual barriers to the harsh materials present in their environment. If the simple diffusion theory is correct, diffusion of small molecules into cells should be an unregulated process. If diffusion is an unregulated process, how could some cells have a lower permeability to small molecules than others?

Second, scientists have already found membrane proteins that facilitate the entrance of water and urea: While the UT2 protein enables transport of urea past the cell membrane, an entire class of membrane proteins called the aquaporins enable the permeation of water into cells. If small molecules enter the cell by diffusion, why would the cell have extra mechanisms to facilitate their entry?


Any Questions?

Q) What's this diffusion thing you keep talking about?

A) Particles randomly flow from areas of high concentration (a lot of particles) to areas of low concentration (not many particles) until they are evenly dispersed.

If you've ever put a normal cell in a concentrated salt solution, you know that it quickly shrivels up. This is because the particles inside the cell want to have the same salt concentration as the medium surrounding it- since the cell membrane does not allow salt to enter the cell, water quickly pushes its way out of the cell, causing it to shrink.

On a similar note, most biologists believe that diffusion is what causes small molecules to pass across cell membranes. According to this theory, small molecules can push their way through the plasma membrane into or out of cells simply because they are diffusing into an area of lower concentration.

Q) What is a Xenopus laevis, and why do I need to know?

A) The Xenopus laevis (pictured at the top of this page) is a species of frog from Southern Africa- it is a claw-toed (platanna), smooth-skinned aquatic frog, roughly 13cm (5in) long when full grown. This species and its eggs are used widely in scientific studies, including this one.

Q) Aquaporin-1 (AQP-1)? Isn't that an aftershave?

A) No, you're thinking of Aquavelva tm. Aquaporin-1 (AQP-1) is a water channel located on cell membranes. The aquaporins are a family of proteins known for facilitating water transport, and AQP-1 (first called CHIP28)...

Find Another Essay On Aquaporin-1

When the Bubble Burst Essay

1539 words - 6 pages , and there is no assurance that the toxic assets are going to be worth anything in the future. Boskin notes, “ Estimates on the losses on U.S. loans and securities range from under $1 trillion to almost $4 trillion. The International Monetary Fund puts them at $2.7 trillion, but the range of uncertainty is enormous.” (Boskin 2) After the housing market crashed I wondered why the banks received all the funds and not the borrowers who had lost

phase diagram Essay

4456 words - 18 pages 348.8 K Relative Error 3.4 7.7 0.6 0.1 1.2 Table 1 Summary of results. A = Naphtalene, B = Durene Figure 1 Phase diagram of (Naphtalene/Durene) system via thermal analysis Figure 2 Phase diagram of (Naphtalene/Durene) system via visual analysis Figure 3Experimental data vs fitted data for runs (1 to 6) Figure 4 Experimental data vs fitted data for

Revolutionary Work of Art

1890 words - 8 pages Walter Benjamin emphasizes in his essay, “The Work of Art in the Age of its Technological Reproducibility” that technology used to make an artwork has changed the way it was received, and its “aura”. Aura represents the originality and authenticity of a work of art that has not been reproduced. The Sistine Chapel in the Vatican is an example of a work that has been and truly a beacon of art. It has brought a benefit and enlightenment to the art

Enlightenment Thought in New Zealand Schools

1594 words - 6 pages . (Kramnick, 1995). The enlightenment movement continued evolving over the following centuries. The main aim of the enlightenment was to make the world more focused on the individual rather than the authority of one person. The individual was not longer under the control of a government that had been given authority from God. Kant (1995) described it as a “man’s release from his self-incurred tutelage.” (p.1). This is talking about the individuals

Psychological Egoism Theory

2240 words - 9 pages The theory of psychological egoism is indeed plausible. The meaning of plausible in the context of this paper refers to the validity or the conceivability of the theory in question, to explain the nature and motivation of human behavior (Hinman, 2007). Human actions are motivated by the satisfaction obtained after completing a task that they are involved in. For example, Mother Teresa was satisfied by her benevolent actions and

How Celtic Folkore has Influenced My Family

1587 words - 6 pages birth to the Celtic Cross (Origins and Influences, 1).” Although I am unsure of what the original Pagan customs consist of, it is clear that the cross has acquired different roles in both Irish history and the Desmond family. With the help of other immigrants and traditions that have been passed on, this piece of folklore has become a symbol of both Christianity and womanhood in my family. As is tradition, my mother would give each of my sisters a

Julia Margaret Cameron

1406 words - 6 pages At a time when women were looked upon as being homemakers, wives, mothers and such the late 1850's presented a change in pace for one woman in specific. Photography was discovered in 1826 and soon after the phenomenon of photography was being experimented with and in turn brought new and different ways of photo taking not only as documenting real time, but also conceptualizing a scene in which an image would be taken. Julia Margaret Cameron will

Evaluation of School Improvement

1403 words - 6 pages improve to incorporate planning, resources, and goals in school districts. Mandates for evaluation presented in the Title 1 Elementary and Secondary Education Act (ESEA) of 1965 became a major section to upgrade schools (Dunn, 2005). This Act and many others, such as No Child Left Behind law (NCLB) began the process of change in education reform. Evaluation actions generate objectives, reliable and useful data for the use of decision-making

Case Study: The Benefits of Animal Testing

1757 words - 7 pages . Scientific American Inc: 1989. Print. “Animal Welfare Act as of February 1, 2010.” Animal Welfare Information Center. United ​States Department of Agriculture. 8 Nov. 2011. PDF. 19 Nov. 2011. “Fast Facts on Diabetes.” National Institute of Diabetes and Digestive and Kidney Diseases. ​National Institute of Health. Feb. 2011. Web. 19 Nov. 2011. “FastStats.” Center for Disease Control and Prevention. National Center for Health Statistics. ​6 Sept. 2011. Web. 19 Nov. 2011. Frankie Trull. “Animals in Research is Critical to Continued Progress in Human Health.” Ed. Jeanne Williams. The Society for Advancement of Education: 1989. Print.

Myth and Magic: Realism in "One Hundred Years of Solitude"

1531 words - 6 pages Garcia Marquez." Wikipedia, the Free Encyclopedia. 1 Dec. 2011. Web. 2 Dec. 2011. García, Márquez Gabriel. One Hundred Years of Solitude. New York: Harper & Row, 1970. Print. MacEwan, Michelle. "The Power of Myth and Storytelling: Part 5 – The Sustenance of Myth." Http://www.michellemacewan.com. Michelle MacEwan Trust, 31 July 2009. Web. 2 Dec. 2011. "Magic Realism." Dictionary.com | Find the Meanings and Definitions of Words at

Adiponectin: a Novel Indicator of Malnutrition and Inflammation in Hemodialysis Patients

2384 words - 10 pages hemodialysis patients which is associated with poor prognosis (1). Possible causes of MICS include comorbid illnesses, oxidative stress, nutrient loss through dialysis, hyporexia, uremic toxins, decreased clearance of inflammatory cytokines, volume overload, increased blood phosphate and dialysis-related factors (1). This syndrome is characterized by coexistent protein-energy wasting and inflammation (2). Low appetite secondary to inflammation is

Similar Essays

Carbamazepine Induced Hyponatremia In Patients Essay

573 words - 3 pages Carbamazepine-induced hyponatremia Drug-induced hyponatremia is commonly associated with diuretics (frusemide, indapamide), selective serotonin reuptake inhibitors (sertraline, fluoxetine) and antiepileptics.[1] A 61-year-old female, 38 kg, was scheduled for debridement and superficial skin grafting for post-burn raw area in right arm. History and physical examination was unremarkable. Blood biochemistry was normal except for serum electrolytes

A Discussion On The Abundance Of Osmolytes

526 words - 2 pages images display aquaporin water channels in the kidney as brown stained rings. In two of the four control slides there is an abundance of these shown indicating these were slides of the inner medulla region or papilla. This conclusion can be drawn because it is known that AQP-1 is heavily expressed in this region due to its water permeating function in the fine control of concentrating urine and regulating cellular volume. The other two control slides however have a diffuse distribution of the water channels, indicating that these are slices of the cortex of the nephron. This is expected because this area is known to be virtually impermeable to water.

Free Energy Essay

1078 words - 4 pages about 15 kcal/mol higher compared with the channel mouth region [18]. Additionally, a predominant obstacle preventing proton leakage comes from the collective macro-dipole at the Asn-Pro-Ala domain (NPA) located at the center of the channel. This NPA domain is slightly wider in diameter than the SF domain and is considered as fingerprint of the aquaporin family. The two oppositely orientated Asn-Pro-Ala sequences at the center of the channel are

Effects Of Salt Water On Osmoregulation

2078 words - 8 pages measured every thirty minutes, for a total of 120 minutes.The results of the NaCl group compared to the water group showed significant differences when compared. The average urine volume for each group was largest at time zero; with the water group's mean volume at 101.3 mL and the NaCl group's mean volume at 129.3 mL (Figure 1). At the 60 minute interval the largest volume difference can be seen between each group (Figure 1). As the experiment