Question

Q1. Data analysis for Figure 4. a. (SA) For each of the phospholipids in the experiment (DLPC, DLPE and DLPS) state if there is a transporter that catalyzes the transverse motion of that phospholipid (from one side of the lipid bilayer to the other) in RBC, and if the transporter is a passive or active transporter. Briefly explain your reasoning b. [SA] What type(s) of phospholipids is/are preferentially translocated by the flippase? Explain. ) 05 1 1.5 2 253 Time hours ure 4. Time course of shape changes (MI) induced by incubating RBCs with the phospholipid vesicles DLPE, DLPS and PC (Adapted from Daleke & Heustis, c. [SAJ Given the distribution of the the membrane, what can you say about the distribution of charge on each side of the membrane? Additional experiments were carried out to ascertain kinetics of flippase activity. In the next few experiments, phospholipid vesicles containing purified dimyristoylphophatidylserine (DMPS) were added. Although DMPS shares similar chemical qualities as DLPS, DMPS diffusion from vesicle to RBC is slower than DLPS (compare the DLPS dynamics in Fig 4 to the control line in Fig 5) allowing for study of factors that affects kinetics of flippase activity.

Answer 1

Answer-1 DLPC- There is no change in shape due to DLPC, as the graph is constant so we can say that this phospholipid is not showing any motion

DLPE- due to this phospholipd there is change in shape of RBC thus there is a transporter for this but it is active

DLPS- due to this phospholipid there is a drastic change in change of RBC thus there is active transporter associated with it

Answer-2 DLPE and DLPS are translocated because flippase is ATP dependent translocase and these are showing active translocation

Answer-3 the cytoplasmic side of RBC will be more negatively charged due to the presence of phosphatidyl serine and also because it is transported rapidly