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Biochemistry DVT 1094 Abdul Muhaimin b. Abd Wahab D11 A007 Azwan b. Kamarudin D11 B038

Biochemistry DVT 1094

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Biochemistry DVT 1094. Abdul M uhaimin b. Abd W ahab D11 A007 Azwan b. Kamarudin D11 B038. Questions. Discuss the effect of abnormalities of cell membrane fluidity. - Azwan Kamarudin - State example of disease and explain how the disease develop. - Abdul Muhaimin Abd Wahab -. - PowerPoint PPT Presentation

Text of Biochemistry DVT 1094

biochemistry

BiochemistryDVT 1094Abdul Muhaimin b. Abd Wahab D11 A007Azwan b. KamarudinD11 B038QuestionsDiscuss the effect of abnormalities of cell membrane fluidity. - Azwan Kamarudin -

State example of disease and explain how the disease develop.- Abdul Muhaimin Abd Wahab -Membrane FluidityIn biology, themembrane fluidityrefers to theviscosityof thelipid bilayerof acell membrane. The membrane phospholipidsincorporatefatty acidsof varying length andsaturation. Shorter-chain fatty acids, and ones with greater unsaturation, are less stiff, less viscous and have lowermelting points.

Factors Effecting Membrane FluidityFactor EffectTemperatureIncreasing temperature increases fluiditySaturation Increased unsaturated fatty acid increases fluidityCholesterolIncreasing the ratio of cholesterol to phospholipid decreases membrane fluidity SteroidsBoth increases and decreases (depending on the steroids)PhospholipidHead group determines the stability of the membranePressureHigher pressure induces ordering of the membrane (less fluid)Abnormalities of Membrane FluidityDecreased erythrocyte membrane fluidityWhat causes ?Due to what disease ?

Decreased lipids membrane fluidityIn what cell ?What causes ?What is Bassen-Kornzweig syndrome ?

1. Decreased erythrocyte membrane fluidity and altered lipid composition in human liver disease.

Changes in erythrocyte membrane lipid composition associated with abnormal plasma lipoproteins in liver disease patient.Cholesterol/phospholipid and phosphatidylcholine/sphingomyeli molar ratios are increased.Phospholipid fatty acid composition is abnormal.Proportion of arachidonic acid, stearic acid are decreased while palmitic acid raised.1. Decreased erythrocyte membrane fluidity and altered lipid composition in human liver disease.

Cause membrane fluidity in patient erythrocytes decrease and fluidity of lipid extracts from membranes patient erythrocytes also decrease.Decrease membrane fluidity is MAIN consequence of altered lipid composition rather than protein abnormalities.

1. Decreased erythrocyte membrane fluidity and altered lipid composition in human liver disease.In liver disease, changes in composition of phospholipid bilayer matrix in erythrocytes membrane has little influence on its fluidity.Reduced fluidity predominantly result of increased in cholesterol relative to phospholipid.

2. Decreased Fluidity of Red Cell Membrane Lipids in Abetalipoproteinemia

Acanthocytic red cells in patients with abetalipoproteinemia (Bassen-Kornzweig syndrom) are morphologically similar to red cells in spur cell anemia.Bassen-Kornzweig syndrome is a rare disease passed down through families in which a person is unable to fully absorb dietary fats through the intestines..Decrease in fluidity of membrane lipids is due to excess cholesterol content.Acanthocyte membranes have an increased content of sphingomyelin and a decreased content of lecithin.2. Decreased Fluidity of Red Cell Membrane Lipids in Abetalipoproteinemia

Increased sphingomyelin/lecithin ratio of acanthocytes is responsible for their decreased membrane fluidity.As in spur cells and in red cells enriched with cholesterol in vitro, this decrease in membrane fluidity occurs coincidentally with an abnormality in cell contour and an impairment in cell deformability.

Spiculated thorny RBCs (acanthocytes) in abetalipoproteinemia individual

Acanthocytes in individual with spur cell hemolytic anemia.

SummaryLiver disease and Bassen-Kornzweig syndrome are the disease that cause decrease fluidity in cell membrane of RBCs.Due to increase of lipid composition.Less permeability to water and other small hydrophilic molecule .Abnormalities in membrane fluidity lead to many disadvantages.