Question

20 The next set of experiments investigated specific metais are required for flippasesc First, RBCs were treated with mixture of an onophors and cheating agent. The inophore "pokes holes in the membranes that ons leak out. The cheating agent binds the lons so they cannot go back inside the cell Following this treatment, the shape change experiments were conducted as usual. After 15 hours, Mgaions were added back to the RBCs. The results are shown in Figure 7. 004 Figure Figure 7. The effect of lon depletion on RBC dangles represent cells treated with an ionophore and EDTA (chelating agent). EDTA (chelating agent). The arrow indicates the point at which Mg" ions were added, and the open triangles are Q4. [SA] Describe and explain the results obtained in Figure 7. What role does Mg2+ play in flippase? OSIMAI What other experiments could be performed using this system? Consider temperature, pH, the addition of ions, cholesterol or detergent, and design an experiment. Specifically define/state: i) the question the experiment will address; ii) main reagents required; II) experimental protocol/method, and; iv) expected outcomes and interpretations. Case 2: A possible mechanism for blindness associated with diabetes: Nat-dependent glucose uptake by retinal cells Adapted from Dr. Kathleen Cornely, Providence College There are two types of cells in the retina: endothelial cells and pericytes, both present in about equal amounts. Pericytes in particular are not well understood, but it is thought that pericyte damage leads to blindness associated with diabetes. It is known that diabetic retinopathy is associated with thickening of the basement membrane (extra-cellular matrix (ECM] material on which the cells sit). Could the pericytes be responsible for this thickening? Wakisaka et al. (Nat-dependent glucose uptake and collagen synthesis by bovine retinal pericytes. Biochim Biophys Acta, 1362, 87-96) sought to determine

Answer 1

4.

Flippases are transport proteins or enzyme present in the membrane of the cell.In RBCs they are involved in the maintenance of the structure of the membrane. So from the graph when initially the peak holes were made  and chelating agents hindered their re entry the membrane lost a modulated arrangement ; the steady state indicates the time span in which cells were kept such.

Back again when the magnesium ions were added the shape started to regain indicating that these ions (magnesium) play a vital role in the flippase activity, the transport by flippases require magnesium.

5.

i)This system can be used to detect he magnesium defeciency in an individual

ii) EDTA tube , Blood ,centrifuge

iii) The collected blood ; plasma and packed volume are checked for the amount og Mg by methods like Mass Spectrometry

iv) Magnesium levels can be noted and deficiency if present can be identified.