Transcript Slide 1
http://www.youtube. com/watch?v=Pfu1D E9PK2w CELL MEMBRANE https://www.youtub e.com/watch?v=rAB KB5aS2Zg CELL SONG 4-2 PARTS OF THE EUKARYOTIC CELL CELL MEMBRANE •Selectively permeable 1. Membrane lipids •both sides of cell surrounded by water; polar hydrophilic phosphate heads orient themselves toward the water; nonpolar, hydrophobic fatty acid tails make up the interior of the membrane and orient themselves AWAY from water •phospholipids form a bilayer; • cholesterol also found among fatty acid tails 2. Membrane Proteins • some are attached to inner or outer surface of membrane – peripheral proteins • others embedded in the membrane and span membrane – integral proteins •integral proteins often have carbohydrates attached to them on the exterior face of the cell – these function as receptors, or for cellular recognition sites – form “fuzzy coat” or glycocalyx 3. Fluid Mosaic Model •membrane is fluid in nature and allows for lateral movement of the lipids and proteins ORGANELLES •contained in the cytosol, a gelatin like fluid containing ions, and organic molecules 1. Mitochondria •site of ATP synthesis •energy of ATP fuels most of the chemical reactions in a cell •surrounded by a double membrane; outer membrane serves as a boundary and inner membrane is highly folded to form cristae, which increase the surface area available for chemical reactions that occur in the mito 2. Ribosomes • NOT surrounded by a membrane • Made up of RNA and protein, assembled in the nucleolus, shipped out through nuclear pores and are found attached to the endoplasmic reticulum (exported or become inserted into membrane) or free floating (proteins made on these remain in the cell interior for use by the cell) 3. Endoplasmic Reticulum •a system of membranous tubules and sacs that function as an intracellular (within the cell) highway •smooth ER synthesizes lipids and carbohydrates, breaks down toxic substances • rough ER makes proteins for export or proteins to be inserted into membranes 4. GOLGI APPARATUS A system of flattened stacks of membranes that process, package and secrete biomolecules for export (proteins, lipids and carbohydrates)