The purpose of this experiment was not only to test the importance of potassium in setting resting membrane potential but also to test the Nernst equation’s ability to accurately portray this. As seen in Figure 1, all but one of the experimentally derived data points were significantly different from the calculated Nernst value, that one point being at 40mM K+. All experimental values before this point were more depolarized than the Nernst equation’s predicted values, while all experimental values after this point were more hyperpolarized than the Nernst equation’s predicted values. Given that most of the p-values in Table 1 do not exceed .05. This showed that most experimentally derived values differed significantly from the Nernst equation …show more content…
The Nernst equation line in Figure 1 shows only how the change in extracellular potassium concentration can lead to a change in membrane voltage. Therefore, the other lines may be a reflection of the effects of chloride extracellular concentration changes. It is important to realize that these changes in chloride concentration also affected chloride’s reversal potential; increases in chloride’s concentration also lead to an increase in chloride’s reversal potential. Given the membrane’s slight permeability to chloride, the ion was able to more easily than other ions travel down its chemical gradient and into the cell. In the areas of the graph where the experimentally derived data points were significantly depolarized relative to the Nernst values, the chloride ion may have had a lowered driving force, given that the pipet did have a minute amount of chlorine in it that entered the intracellular environment. The point (40mM K+) at which the Nernst equation accurately showed potassium as the main ion which set this particular membrane potential, may have been caused by chloride reaching it’s reversal potential. Note that this reversal potential of about - 40mV is higher than chloride’s usual reversal potential of -70mV. At this point there is no net flow of chloride. However, the following increases in chloride concentration in the extracellular space caused for an increased driving force on chloride to enter the
Compress the safety bulb, hold it firmly against the end of the pipette. Then release the bulb and allow it to draw the liquid into the pipette.
Thorough analysis of the graph displayed enough evidence suggesting that an increase in substrate concentration will increase the height of bubbles until it reaches the optimum amount of substrate concentration, resulting in a plateau in the graphs (figure 2). Hence; supported the hypothesis.
Because it is a way of knowing the pressure that the blood is putting on the walls of arteries and veins.
Okay, if our lithium weight is going to be 6.941 g/moL Then that means we have to take 24.6g of Lithium and multiply it by 1 mol of Lithium over 6.941 g of Lithium. This would equal to be 3.544 mol of Lithium. Then we have to take that 3.544 and multiply it by 1 mol of hydrogen gas over 2 mol of lithium. Which would then equal into 1.772 mol of hydrogen gas. We can then figure out that 1.772 is our “n”. The “T” is our 301 Kelvin, the “P” is our 1.01 atm and the “R” is our 0.0820 which would be the L atm over mol k. And we can’t forget about our “V” which would be V equals nRT over P which equals 1.772 mol divided by 0.0820 L atm over mol kelvin multiplied by 301 kelvin over 1.01 atm which equals to our final answer of: 43.33 of H2
The pump exchanges three sodium molecules for two potassium molecules. In doing so an electrical gradient is formed across the basolateral membrane of the cell due to the imbalance of charge generated. The interior of the cell is negative by about 80mV in relation to the outside...
There are a series of nodes along the axon where there is a high concentration of sodium (Na+) and K+ channels. There is a high concentration of Na+ outside the cell and a high concentration of K+ inside the cell. As the nodes sen...
Lab 1 demonstrates the capabilities of congestion control algorithms implemented by Transmission Control Protocol (TCP). It provides three scenarios to simulate these algorithms and will later compare the results.
Potassium is the main intracellular (inside the cell) cation, which works with sodium, the main extracellular (outside the cell) cation, to maintain water and electrolyte balance in the body. This function influences most of its actions in the body, including the following:
problems within the specific ion channels known to cause the disease. The goal of the
The experiment is aimed at giving a better understanding of the osmosis process and the different conditions in which osmosis occurs. INTRODUCTION When a cell membrane is said to be selectively permeable, it means that the cell membrane controls what substances pass in and out through the membrane. This characteristic of cell membranes plays a great role in passive transport. Passive transport is the movement of substances across the cell membrane without any input of energy by the cell.
Simon, E. J., Reece, J. B., Dickey, J. L. (02/2012). Campbell Essential Biology with Physiology, 4th Edition [VitalSource Bookshelf version 6.2]. Retrieved from http://online.vitalsource.com/books/9781256902089
In life, it is critical to understand what substances can permeate the cell membrane. This is important because the substances that are able to permeate the cell membrane can be necessary for the cell to function. Likewise, it is important to have a semi-permeable membrane in the cell due to the fact that it can help guard against harmful items that want to enter the cell. In addition, it is critical to understand how water moves through the cell through osmosis because if solute concentration is unregulated, net osmosis can occur outside or inside the cell, causing issues such as plasmolysis and cytolysis. The plasma membrane of a cell can be modeled various ways, but dialysis tubing is especially helpful to model what substances will diffuse or be transported out of a cell membrane. The experiment seeks to expose what substances would be permeable to the cell membrane through the use of dialysis tubing, starch, glucose, salt, and various solute indicators. However, before analyzing which of the solutes (starch, glucose, and salt) is likely to pass through the membrane, it is critical to understand how the dialysis tubing compares to the cell membrane.
Introduction Paramecium are single cell organisms that have randomized motion in aqueous solutions, mainly water based solutions. These cells, like many others, have a permeable membrane that allows certain molecules with a net ionic charge to bypass the membrane which in turn helps the paramecium to create an electrostatic potential difference across their membrane that allows them to swim. The purpose of this experiment is to measure the effects of KCL on the plasma membranes of paramecium. When the cell is present in a high ionic solution, the cell develops an electric gradient across its membrane that is higher than usual due to the concentration of ions readily available in the solution in which they are in.
SN2 reactions are described as bimolecular nucleophilic substitution reactions that occur in one concerted step without the formation of a carbocation intermediate. These reactions are performed most effectively in polar aprotic solvents such as acetone. The steric hindrance presented in the substrate is considered the most important factor due to the fact that the more steric hindrance there is around the halide, the harder it is for it to leave. The collected data for the SN2 reactions support this logic by showing that primary halides on substrates 4, 6, and 7 occurred within the first 5 minutes of the reaction. Substrates 6 and 7 were acted on immediately because 6 is allylic and 7 is benzylic, which creates an over lap of the pi bonds
Activity 3: Investigating Osmosis and Diffusion Through Nonliving Membranes. In this activity, through the use of dialysis sacs and varying concentrations of solutions, the movement of water and solutes will be observed through a semipermeable membrane. The gradients at which the solutes NaCl and glucose diffuse is unproportional to any other molecule, therefore they will proceed down their own gradients. However, the same is not true for water, whose concentration gradient is affected by solute ...