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Cell membrane experiments
Bio lab experiment 10 cellular membranes
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Recommended: Cell membrane experiments
MATERIAL AND METHODS
Stability of cell membrane using pH
For the lab experiment for testing the stability of beet cell membranes using pH, many materials were used as follows. Obtaining a beet we punch out cores, using a cork borer. After washing the cores we put each one inside a separate test tube, and added a different pH solution in each one. After 3 minutes in these exposure solutions, we took the beet out with a dissecting needle. Then transferred each beet to a separate test tube containing deionized water. After 20 minutes in these diffusion solutions, we took the beets out with a dissecting needle and discard it. We then stirred each solution in the test tube with a stirring rod, and transferred it to a cuvette. A spectrophotometer was then calibrated, and used to measure the absorbance of each exposure solution, and diffusion solution.
Membrane Damage
For the lab experiment for Membrane Damage, we tested the extract pigment and diluted it. When the pH solutions are added, this will cause it to be in a range of absorbance. We used materials as follows. Obtaining a beet we proceeded to cut small individual cubes. We then rinse each cube to remove any damaged pigments with deionized water. Using a blender, we blend the beets with 15 mL of pH 7 DI water. After blending we used cheesecloth to separate the liquid from the solids for easier centrifuge process. Then we put the liquid beet into a centrifuge tube and centrifuge it for 5 minutes at 2500 rpm. We then remove the supernatant into a beaker, and discarded the sediment. Using a 1:4 ratio mixture of the supernatant and deionized water, we made a stock solution. We then tested the stock solution’s absorbance with a spectrophotometer, and place 1 mL of the solution into separate test tubes. Next we added an additional 4 mL of pH solutions in the 2-11 range into each test tube. After mixing, we tested the absorbance for each solution using a spectrophotometer.
Mixing the Diffusion and Exposure Solution
For the lab experiment of mixing the diffusion and exposure solution, we are going to test if the pigment is released in the exposure solution. We used materials as follows: Obtaining a beet, we punched out 2 cm long beets using a cork borer. Then we wash the beets in running water, after that we prepared 10 test tubes each containing different pH solution.
Experiment #3: The purpose of this experiment to test the chromatography of plant pigments the alcohol test strip test will be used.
Intro: It has been said many times that "You can't judge a book by its cover" and "Don't judge a man until you have walked a mile in his shoes". A person may appear one way on the outside but may be feeling the total opposite on the inside. They may be masking their true emotions with a false appearance. In "We Wear the Mask" it seems that Paul Laurence Dunbar is conveying this message to his audience. Looking at the picture of the girl holding the mask, seems similar to the emotions expressed throughout the poem.
Dunbar begins his poem by introducing the idea of deception through a symbolic “mask”. In the first two lines, Dunbar states “we wear the mask that grins and lies, / it hides our cheeks and shades our eyes” (1,2). These lines portray an image of a dishonest face partially because of Dunbar’s word choice and partially because masks have been used as tools of disguise throughout history. However, the lines
The Cask of Amontillado is considered to be one of the best short stories. Written by Edgar Allan Poe in first person and having all the main events as a three hundred page fiction book, The Cask of Amontillado is a complete novel. This short story has several themes which function from the first page of the story such as: suspense, fear, and revenge.
After five the test tube was removed and cooled to room temperature. Three more test tubes were obtained and labeled 1, 2, and 3. The correct reagent was added to each test tube as seen. The spectrophotometer was adjusted
Osmosis is a type of diffusion which is only applied on water and is a passive process which does not require an input of energy from the cell; this is because materials are moving with the concentration gradient. Osmosis is a process that occurs at a cellular level, which entails the spontaneous net movement of water through a selectively permeable membrane, from a region of high to low water concentration, in order to equalise the level of water in each region. This form of diffusion takes place when the molecules in a high concentration are too large to move through the membrane. The term semi-permeable or selectively permeable means that some substances can easily pass through the cell membrane, whereas others cannot. The significance of osmosis to cells is great, since it is the osmotic pressure that maintains the shape of an animal cell and provides support in the plant cells. Many factors affect the rate of osmosis including size of particles and temperature however in this particular experiment the factor investigated is the concentration of sodium chloride. Tubes of potatoes will be used to demonstrate the fact...
...is presented in a way that “blacks or whites can draw admonition from the subject” (1) . Another perspective from Revell is that the poem presents itself in terms of passionate personal regret. Revell believes that Dunbar felt guilty because he allowed himself to be bound to the “ plantation lifestyle” (1). The plantation life style internal anguish and agony the blacks went through as slaves. Some blacks have moved on from it, but some continue to use slavery as an excuse to not progress in life. It should be noted that Revell draws the most attention to the middle of the poem. The poem itself is masked because it never specifically says who its linked too, even though most would infer that it is linked to the black race. Revell concludes that Dunbar left aside the preconceived image of what it meant to be black in America, and spoke “only from his heart” (1) .
The title itself directs readers towards a sense of assimilation by wearing a mask. Wearing a mask indicates hiding an original identity in order to please the mainstream one. This is exactly the case in “We Wear the Mask”. In this case, blacks had to hide their humiliation and suffering from their white counterparts by wearing a mask that lies. When Dunbar wrote, “With torn and bleeding hearts we smile” (646), it is evident that African Americans were forced to hide their pain by showing a fake smile. They suffered emotionally on the inside but could not express it. In addition to showing a fake smile, African Americans did not care about their heritage. The third stanza reads, “But let the world dream otherwise, / We wear the mask!” (14-15). The lines do not celebrate cultural heritage because the slaves had to show pleasure while they are being tortured. Letting the world dream otherwise shows the slaves’ carelessness when it comes to expressing their identity.They are concealing their true self by hiding their pain. Hiding their pain also means hiding their cultural
The American dream has lost a lot of its innocence as America has developed. Everything in the America of today has become business based, and as a result the purity of the original American Dream has been tainted. It seems necessary in modern society to have loose morals to be successful. Perhaps this is where the American Dream really started to deteriorate; when someone realized they could achieve success much faster by capitalizing at another’s expense. Scott Fitzgerald’s character Gatsby found this out. In his younger days Gatsby had a regiment for self-improvement, a testament to his willingness to work for success and break through class barriers. However, Gatsby learns that the world does not work that way. Gatsby is supposed to have
The effect of temperature on the beetroot membranes Aim of the research: The aim of this investigation is to determine what kind of effect will the increasing temperature have on the plasma membrane of a beetroot cell. Introduction The beetroot contains a red pigment that is kept in the cells by the membranes. If the membranes are damaged, the pigment “betalain” will leek out. The amount of pigment that leeks out can be assessed, as “betalain” will colour any water that surrounds the cell.
Paul Laurence Dunbar’s “We Wear the Mask” is a lyric poem in which the point of attraction, the mask, represents the oppression and sadness held by African Americans in the late 19th century, around the time of slavery. As the poem progresses, Dunbar reveals the façade of the mask, portrayed in the third stanza where the speaker states, “But let the dream otherwise” (13). The unreal character of the mask has played a significant role over the life of African Americans, whom pretend to put on a smile when they feel sad internally. This ocassion, according to Dunbar, is the “debt we pay to human guile," meaning that their sadness is related to them deceiving others. Unlike his other poems, with its prevalent use of black dialect, Dunbar’s “We Wear the Mask” acts as “an apologia (or justification) for the minstrel quality of some of his dialect poems” (Desmet, Hart and Miller 466). Through the utilization of iambic tetrameter, end rhyme, sound devices and figurative language, the speaker expresses the hidden pain and suffering African Americans possessed, as they were “tortured souls” behind their masks (10).
Gender roles have been a predominant factor in our world since the early emergence of human societies whether they are positive or negative. They are based on expectations that societies have over the people in them. The Epic of Sunjata, shows us how men and women are treated almost equally in different forms. Women are praised for their ability to birth leaders, which is similar to the early Greek Society. In most societies, women are treated less equal than men. This was prevalent in the early Indian society. No matter the gender role, it has been shown that any society cannot survive without both men and women.
== § Test tubes X 11 § 0.10 molar dm -3 Copper (II) Sulphate solution § distilled water § egg albumen from 3 eggs. § Syringe X 12 § colorimeter § tripod § 100ml beaker § Bunsen burner § test tube holder § safety glasses § gloves § test tube pen § test tube method = == = =
James Gargano, a famous critic, said The Cask of Amontillado was a masterpiece; a powerful tale of revenge; one of Edgar Allan Poe 's richest aesthetic achievements; deserves more analysis than it has received; and that critics have rightfully expressed admiration for the tale (Gargano). Like Gargano, many critics give Poe’s The Cask of Amontillado great acclamation. Though few critics are displeased with the narrator, The Cask of Amontillado is widely praised by most critics. "The Cask of Amontillado" is a work of art, and not just an ingenious Gothic exercise” (Milne). Other critics such as Bettina Knapp and Charles Dana, did not like The Cask of Amontillado or that Montresor felt no guilt. Poe 's characters murder and commit heinous crimes and feel no remorse towards their victims. "Bettina Knapp places ‘The Cask of Amontillado’ among Poe 's ‘shadow tales,’ which do not offer values. No judgmental forces are at work. Crime is neither a negative nor a positive act. Poe 's psychopaths do not distinguish between good and evil, nor do they usually feel remorse or guilt”
There were five test solutions used in this experiment, water being the control, which were mixed with a yeast solution to cause fermentation. A 1ml pipetman was used to measure 1 ml of each of the test solutions and placed them in separated test tubes. The 1 ml pipetman was then used to take 1ml of the yeast solution, and placed 1ml of yeast into the five test tubes all containing 1 ml of the test solutions. A 1ml graduated pipette was placed separately in each of the test tubes and extracted 1ml of the solutions into it. Once the mixture was in the pipette, someone from the group placed a piece of parafilm securely on the open end of the pipette and upon completion removed the top part of the graduated pipette.