The results of our experiment were similar to the actual isoelectric point of BSA with the exception of one data record. The calculated pI for BSA was approximately 4.5 after experimentation in comparison to 4.7, the real pI value of BSA. The isoelectric point was calculated after graphing the averages of each buffer solution and taking the x-intercept of the data. The isoelectric point detailed the pH at which the substance had a net charge of zero. The second strip of pH 6.0 with a value of +5mm, was omitted from calculations to improve the accuracy and precision of data. Buffers with a pH greater than the isoelectric move towards the negative end. Most of the buffer solutions with a pH of 4.7 and greater from the data, migrated to the negative …show more content…
What is electrophoretic mobility? Describe two ways in which the mobility of a molecule is affected during electrophoresis. Electrophoretic mobility is the ability of substance to migrate during a period of time which is proportional to speed. The speed and distance a molecule or substance moves in result of the electric field that electrophoresis applies, can indicate the size and charge of the molecule. Bigger molecules will move slower than small and greater net charges will move faster to the opposite charge. 3. For this experiment, your sample was applied to a cellulose acetate strip and the migration in an electric field was measured at various pH values. There are other methods that can be used during an electrophoresis experiment. Discuss one alternative electrophoresis method and compare and contrast it to the method used in lab this week. In slab gel electrophoresis agarose or polyacrylamide is used. The conducting buffer is contained in the porous gel and the gel is then poured in between glass plates. These plates are separated by spacers. An electric field is applied at the rear after the substance of experimentation is added to the wells at the top. The substance will then move a certain distance towards the positive electrode. This method uses gel unlike the cellulose acetate strips but it still uses a buffer and a electric field to migrate the substances based on their size and charge. Slab gel electrophoresis is usually used in the biological
“Active transport, the protein transporter moves molecules against, or up, the concentration gradient” (McCance & Huether, pg. 29).
After you have reviewed the principles of electrophoresis, use what you know to complete the following:
1. In passive transport, what determines the direction of movement of small particles? The direction of movement of particles in passive transport is determined by the concentration gradient (diffusion) between the cytoplasm and the extracellular fluid. 2. Why do the molecules in facilitated diffusion need help moving across the plasma membrane? Likely, the molecules are too large to pass unaided through the plasma membrane with the concentration gradient; they need to pass through special transport proteins.
The mole is a convenient unit for analyzing chemical reactions. Avogadro’s number is equal to the mole. The mass of a mole of any compound or element is the mass in grams that corresponds to the molecular formula, also known as the atomic mass. In this experiment, you will observe the reaction of iron nails with a solution of copper (II) chloride and determine the number of moles involved in the reaction. You will determine the number of moles of copper produced in the reaction of iron and copper (II) chloride, determine the number of moles of iron used up in the reaction of iron and copper (II) chloride, determine the ratio of moles of iron to moles of copper, and determine the number of atoms and formula units involved in
A major determinant of diffusion in a biological system is membrane permeability. Small, uncharged molecules pass through cellular membranes easily, while most and/or charged molecules cannot pass through the membrane. The movement of water across a selectively permeable membrane, like the plasma membrane
Diffusion is the movement of molecules from an area of high concentration to an area of low concentration until equilibrium is reached. Osmosis, however, is the movement of water according to its own concentration gradient across a selectively
Cells and molecules in the environment are constantly moving and changing, for cells to function properly there is a need for equilibrium to be met. The size of the cell and the solution outside of the cell affects the rate of diffusion and osmosis in the cell. Cells are constantly trying to reach an equilibrium with the molecules and substances around it, which is why there are such terms as: hypertonic, hypotonic and isotonic. The procedures allowed testing of whether or not surface area or volume increased diffusion and how different substance control diffusion. Cells are constantly moving to reach equilibrium through diffusion and osmosis.
The establishment of electrochemical gradient is one of the driving forces for ion movement across the cell membrane. Cells are usually negative and surrounded by positively charged extracellular fluids. All transport processes across cells impact the chemical gradients. There are two primary transport processes that affect electrical gradients, electroneutral carriers and electrogenic carries. Electroneutral carries transport uncharged molecules or exchange an equal number of particles with the same charge across the membrane, ultimately not changing the overall elecrtochemical gradient. Electrogenic carriers result
All cells contain membranes that are selectively permeable, allowing certain things to pass into and leave out of the cell. The process in which molecules of a substance move from an area of high concentration to areas of low concentration is called Diffusion. Whereas Osmosis is the process in which water crosses membranes from regions of high water concentration to areas with low water concentration. While molecules in diffusion move down a concentration gradient, molecules during osmosis both move down a concentration gradient as well as across it. Both diffusion, and osmosis are types of passive transport, which do not require help.
In this lab, neutral red was used as a pH indicator. The color changes from yellow to red in a basic solution to an acidic solution. The neutral red dye was applied to Saccharomyces Cerevisiae. When the S. Cerevisiae cells come in contact with the neutral red dye, the dye gets to the cell by crossing the cell membrane. The cell membrane is the outer surface of the cell that functions as a barrier. The outside of the cell membrane is made of lipid and membrane proteins (Hardin, 2012). It is selectively permeable, which means only select ions and molecules can pass through it by transport. Membrane transport can be actively or passively moving a substance from side of the membrane to another (Hardin, 2012). Passive transport does not require energy to move molecules across the cell membrane. Diffusion is a form of passive transport that moves molecules across the membrane from an area of higher concentration to an area of lower concentration. Osmosis, diffusion, and facilitated diffusion are all examples of passive transport. Active transport requires energy to move molecules across the membrane from areas of lower concentration to higher concentration. It requires energy because it pushes sodium ions (Na+) and potassium ions (K+) (Hardin, 2012). When the dye entered the cell, it also showed its location. Sodium azide (Na+N3-) is a metabolic inhibitor that blocks the flow of electrons along
Diffusion is the movement of molecules from a region of higher concentration to a region of lower concentration. The rate at which molecules diffuse can be determined by the relationship of molecular weight and that rate of diffusion through a membrane. Hypothesis of this experiment is that the fluid with higher molecular weight will diffuse at a slower rate and distance.
Cells are always in motion, energy of motion known as kinetic energy. This kinetic energy causes the membranes in motion to bump into each other, causing the membranes to move in another direction – a direction from a higher concentration of the solution to a lower one. Membranes moving around leads to diffusion and osmosis. Diffusion is the random movement of molecules from an area of higher concentration to an area of lower concentration, until they are equally distributed (Mader & Windelspecht, 2012, p. 50). Cells have a plasma membrane that separates the internal cell from the exterior environment. The plasma membrane is selectively permeable which allows certain solvents to pass through
For this process it is often only found when the particles or cells move down from their concentration gradient from one area of higher concentration to an areas of lower standard. The most common type of passive transport is known as Osmosis. This process is solely responsible for moving water throughout a cell membrane. Other types of particles can also move throughout the cell as well. They are frequently very small molecules such as oxygen and simple pass between the spaces in the lipid bilayer of the cell's membrane. This is a very difficult or hard to understand process. However, it is a very important process that all cells need to survive. One type of passive transport is diffusion. This process is the process which it moves things from a higher concentration to a lower concentration. The difference between the concentration between the two areas is often called concentration gradient. Diffusion will continue until this gradient is terminated or no longer is there. Since diffusion moves material from an area of higher concentration to an areas of low concentration it is, identified as moving solutes "down the concentration gradient". However, in many cases the moving forces of passive transport can not be identified to the simplified
diffusion is one of the passive transport processes. it is used in oxygen entering a cell and carbon dioxide leaving a cell. diffusion is the movement of particles such as atoms or molecules from a high concentration place in an area of a low concentration. this shows that they diffuse down the concentration gradient. the concentration gradient is a gradual change in the concentration of solutes in a solution as a function of distance through a solution. in biology a gradient results from an unequal distribution of particles across the cell membrane. When this happens solutes move along the concentration gradient until the concentration of the
The plasma membrane, as well as lipids, includes several proteins; the proteins that are within the membrane are found buried or embedded into the lipid bilayer. These proteins include enzymes, receptors and antigens. There are four methods of transportation both in and out of a cell; diffusion, facilitated diffusion, osmosis, and active transport. Fick's law is used to measure the rate of diffusion: [IMAGE] Diffusion is the movement of atoms, molecules or ions from a region of high concentration to a region of low concentration (down the concentration gradient²). The energy for this to occur comes directly from the particle itself; this is defined as passive (not requiring energy).