If you were looking at an enlarged liver cell (60 microns in diameter), how many mitochondria could it hold assuming there were no other cellular components? (Assume mitochondria are spherical with a diameter of 1.4 µM; assume the liver cell is spherical, and the volume of a sphere is 4/3 t º ).

4) Two membrane preparations have been made from the plasma membrane of erythrocytes (i.e red blood cells) and are being maintained in an isotonic buffer solution: (1) right-side-out membrane vesicles, in which the exoplasmic leaflet of the vesicle faces the buffer (equivalent in orientation to that of the exoplasmic leaflet of the intact plasma membrane); and (2) inside-out membrane vesicles in which the exoplasmic leaflet faces the interior of the vesicles and the cytoplasmic leaflet faces the buffer. 80 a. Right-side-out vesicles (ROVS) Very Low Fluorescence Inside-out vesicles (IOVS) Very High Fluorescence A newly discovered phosphoglyceride, called phosphotidylalanine is currently being studied. Annexin V is a protein that binds to phosphatidylalanine, which is one of the phospholipids present in the cell membrane preparations described above. Fluorescently labeled Annexin V is mixed with each vesicle preparation. The vesicles are washed to remove unbound Annexin V and then…

For the following questions, match the labeled component of the cell membrane (Figure 3) with its description. Write the letter that corresponds the concept being asked. E D- Figure 3. 1. Peripheral protein 2. Cholesterol 3. Fiber of the extracellular matrix 4. Microfilament of the cytoskeleton 5. Glycolipid

A solution containing 3.58 x 1023 molecules/m3 of protein in water is separated from pure water by a membrane 3.20 μm thick.  The diffusion coefficient of the protein through the membrane is 7.15 x 10-18 m2/s.  On average, how many molecules cross 0.0240 μm2 of this membrane each second? [Answer as a positive number with 3 sig digits, but do not enter units with your answer]

The surface area to volume ratio affects the ability of the cell to exchange nutrients and waste products with the outside environment. Many factors affect the movement of molecules across the cell membrane, including membrane thickness, temperature, pressure, concentration gradient, molecular mass, distance travelled, solvent properties and surface area of the cell. In general, according to Einstein’s approximation equation (Equation 1), diffusion time is inversely proportional to the to the diffusion coefficient (D), where t is time and x is distance travelled. The diffusion coefficient is unique to each type of molecule and is determined experimentally. Waste products such as carbon dioxide (CO2) pose a unique problem to cells as their accumulation may be lethal. Exchange with the external environment is dependent upon the distance the waste must travel; for a round cell this will be up to half the cell diameter. Using the diffusion coefficient (D) for carbon dioxide (1.97 × 10-5…

An artificial cell consisting of an aqueous solution enclosed in a selectively permeable membrane (but with no cell wall) is immersed in a beaker containing an aqueous solution. The outside environment concentration consists of 0.01 M glucose and the inside of the cell has a concentration of 5.0 M glucose. The plasma membrane is permeable to water and monosaccharides, but impermeable to the disaccharides. Complete the following for the image below: Is the glucose going down or against its concentration gradient? Is the movement of the solute in the cell going out of the cell?       Down...Yes     Down...No     Against...Yes     Against...No

Shown below are cells (colored) that were recently placed into a beaker containing a clear solution For each scenario, indicate whether movement of the molecule into the cell will occur using facilitated diffusion or active transport. А. B. 125mM 20mM fructose glucose 85MM 35mM fructose glucose OA= facilitated diffusion; B= facilitated diffusion OA= active transport; B= active transport O A= active transport; B= facilitated diffusion A= facilitated diffusion; B= active transport

Of the following cell membrane lipids, which one prefers to reside in the inner leaflet (or inner half) of the membrane bilayer, AND has an overall neutral charge at physiological pH (7.4)? a) PE (phosphatidylethanolamine) is inner-leaflet with an overall neutral charge at pH 7.4 b) SM (sphinogomyelin) is inner-leaflet with an overall neutral charge at pH 7.4 c) PS (phosephatidylserine) is inner-leaflet with an overall neutral charge at pH 7.4 d) PC (phosphatidylcholine) is inner-leaflet with an overall neutral charge at pH 7.4

The classic demonstration that cell plasma membranes are composed ofbilayers depends on the following kinds of data:• The membrane lipids from 4.74 x 109erythrocytes will form a monolayer of area 0.89 m2when spread on a water surface.• The surface of one erythrocyte is approximately 100 μm2in area. Show that these data can be accounted for only if the erythrocyte membrane is a bilayer.