Structure Of Cell Membranes Flashcards
Roles of cell membranes at the surface of cells
Separates cells contents, regulates transport of materials in and out, contains enzymes involved in specific metabolic pathways, releases chemicals to signal other cells,
Roles of cell membranes within cells
Mitochondria have folded inner membrane to increase SA, inner membrane of chloroplasts contains chlorophyll, digestive enzymes catalyse reactions
Explain fluid mosaic model
Singer and Nicholson 1972
Mosaic- bilayer with proteins floating in it
Fluid - lipid molecules change places and some proteins move
Membrane in neurones
Protein channels and carriers allow entry and exit of ions
Myelin sheath gives several layers of membrane
Membrane in white blood cells
Special protein receptors recognise antigens of foreign cells
Membrane in root hair cell
Many carrier proteins to actively transport nitrate ions
Membranes in mitochondria
Folded inner membrane gives large SA
Phospholipid bilateral contains
Phospholipids (hydrophilic head, phobic tail)
Cytoskeletal filaments
Cholesterol - strength and flexibility
Channel and carrier proteins
Glycolipid - carb chain attached to lipid
Glycocalyx - v hydrophilic
Glycoproteins - carb chain attached to protein