HSCI 100 Lecture Notes - Nuclear Membrane, Cell Membrane, Membrane Transport Protein

• School: Simon Fraser University
• Department: Health Sciences
• Course: HSCI 100
• Professor: Nienke Van Houten

Document Summary

Surface to volume ratio as cell gets larger, sa increases much more slowly than volume: nutrients enter cell and waste leaves @ surface larger cell difficulty moving nutrients across inadequate surface would not survive. Random move from higher concentration to lower concentration. Concentration gradient: difference in relative number of molecules/ions in given substance in two adjacent. Passive transport (doesn"t require energy) areas: facilitated diffusion. With concentration gradient: osmosis (cross through protein) Water moves from higher h2o concentration to lower. Against concentration gradient (lower concentration to higher) Na+/k+ pump bodies have higher potassium, lower sodium: exocytosis, endocytosis. Membrane pinches in and forms vesicle that brings substances in. Hypertonic more solute than inside of cell: water flows out of cell, cell shriveling. Hypotonic less solute than inside of cell: more water outside water flows into cell, cell swelling/burst. Isotonic solutions equal amounts of solute inside & outside of cell.