Question

The plasma membrane is phospholipids, cholesterol, and peripheral proteins True or False

Answer 1

Ans:- True.

plasma memebrane is composed of

LIPID :- 40% (eg phospholipid , cholesterol)

membrane protein -- 55%

carbohydrate -5%

LIPIDS IN CELL MEMBRANE 00:10:55 .3 groups Phospholipids (most abundant) Glycolipids Cholesterol. . Lom site Phospholipids Phosphatidylcholine : o/k/a Lecithin lungs (surfactant) Lok/a major surfactant lipid i) Sphingomyelin : L» minor surfactant lipid, also a component of nerve cell membrane Ratio 2 a → Adequate Fetal lung maturity S iiPhosphatidylserine : La Normally present over Inner cell membrane • outside exposure of PS → Apoptosis --> Annexin V PS Complex To determine Apoptosis "Annexin V staging" iv) phosphatidyl inositol : 1P, La 'messenger CIP, - DAG ca at] Cardiolipin : : Seen in mitochondrial membrane of human heart In syphillis serum o for Anti Cardiolipin Antibodies + VORL - Test GLYCOLIPIDS 00:24: as • mc seen in Brain GIT a isoforms j) Gangliosides id cerebrosides Gmi Gangliosides - Seen in GI tract epithelium Lo receptor for Cholera Toxin

CHOLESTEROL 00:26: SO Precursor → "Vit D" UV-B Skin →7 dehydro cholesterol (280-320) Sun → Vit D Cholesterol → Fluid state → Rich in PUFA →n membrane fluidity Linoleic Acid Linolenic Acid-Essential Fatty Acids Arachidonic Acid saturated FA membrane fluidity Laka Trans fatty acids ---->Stearic acid, Palmitic Acid Cholesterol is k/a Fluidity Buffer of cell membrane PROTEINS IN MEMBRANE 00:36:17 Protein → major content of cell membrane (55%) Types: 1) Transmembrane p/integtral P Peripheral P ii) Lipid Anchored p j) Transmembrane Protein : La GPCRS (G-protein coupled Receptors) b) Nat Ki Pump → lon channels & Pumps → CFTR Gene - Regulate opening of cl ion channel Function mutation cystic fibrosis oskeletal muscle - iD Peripheral proteins Seeningo RBC - Spectrin, Ankyrin Dystrophin ✓ Function supportive protein (i.e. structural support) Spectrin > Hereditary Elliptocytosis 2 Hemolytic Ankyrin -> Hereditary Spherocytosis) Anaemias Dystrophin mutation, Duchenne muscular Dystrophy Gower's sign ✓ ✓ mutation

idLipid Anchored Proteins - aka GPI Proteins ✓ip is the lipid for attachment ✓ seen in RBC → 0055, 0059 ✓ Function - Prevent Hemolysis if GPI protein absent → paroxysmal nocturnal hemoglobinuria CARBOHYDRATE ✓ 5% of cell membrane ✓ In nerve cell membrane → myelin © La protein is aoth, Lipid is 80%