The Phospolipid Bilayer
Our cell membrane is made up of a dispersion of different proteins onto a 2 dimensional fluid of lipids, compounded mainly of phospholipids, a class of membrane lipids that are amphipathic in their properties, meaning that they are both hydrophilic and hydrophobic (Ratto, 2002). Of all the phospholipids, the most common type that makes up most cell membranes is phosphatidylcholine, which has a hydrophilic head group and two hydrophobic hydrocarbon tails (Alberts et al, 1998, p349). Because of their hydrophobic nature, the hydrocarbon tails resist against the aqueous environment, thus, forcing away from it leaving the hydrophilic head groups exposed to the aqueous environment, hence, forming a bilayer (Alberts et al, 1998, p350). The hydrophilic head groups face the outside environment and the hydrophobic tails face each other (Hanke and Schlue, 1993). The main focus is, however, the fluidity of the phospholipid bilayer and a disease involving the phospholipid bilayer called Antiphospholipid Syndrome. The phospholipids in membranes are fluid because they can move laterally from one place to another in the plane of the bilayer without being restrained (Alberts et al, 1998, p352); hence, scientists
One experiment that scientists manipulated to prove this was the Fluorescent Recovery After Photo-Bleaching (FRAP) experiment (Bultmann, T. This is done by labelling a region on the cell membrane and then bleaching a spot on that region; subsequent analysis showed that the fluorescent intensity of the bleached spot increases with respect to time. Antiphospholipid Syndrome is of a similar cause where the phospholipids in our cell membrane are recognized as foreign (Rand 2002); thus, our body produces antibodies that targets the antigen, indentified as antiphospholipid antipbody-(beta)2 glycoproteinI complex, and attacks anionic phospholipid-protien complexes (Rand 2002). When anionic phospholipid-protein complexes are recognized as foreign by our immune system, the antibodies produced attacks these complexes (Rand 2002): this is the possible mechanism that explains recurrent pregnancy loss and thrombosis with experimental evidence (Rand 2002). When that is done, other diagnostic factors are considered such as thrombosis, clots in blood vessels; thrombocytopenia, loss of platelets; and recurrent pregnancy loss (Rand 2002). Scientists bleached a spot on the fluorescent region by exposing it to extreme bright light called laser (Bultmann, T. The phospholipid bilayer is important to the cell because it provides a barrier to the outside environment, controls the transport of certain ions and solutes, and regulate the communication between cells (Hanke and Schlue 1993). named the phospholipid bilayer "The Fluid Mosaic Model" (Hanke and Schlue 1993). The major problem is, sometimes by mistake, our immune system recognizes its own parts as foreign; for example, the cells in our body are sometimes recognized as foreign (Rand 2002) . Two antibodies are known: Lupus anticoagulant (LAC) and anticardiolipin (ACA) (Rand 2002).
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