PNB 2264 Lecture Notes - Lecture 6: Main Source, Tonicity, Potassium Channel

• School: UConn
• Department: Physiology and Neurobiology
• Course: PNB 2264
• Professor: Kristen Kimball

Document Summary

Double layered membrane: internal surface membrane, hydrophobic tail, phospholipid bilayer. Protein molecule: hydrophilic head, external membrane surface. Peripheral proteins: attach to either inner or outer face of membrane. Integral proteins: protrude partly or all the way across the membrane, include channel proteins and carrier proteins. Drop of oil floating on water and it stays together and float in the ocean, doesn"t dissolve in the ocean. Paracellular: between cells: squeeze between the spaces, hard because of junctions. Tight junctions are like a zipper: no way to regulate this transport. Transcellular: through cells: selectivity to get across this membrane, channels of transporters. Relatively few molecules are permeable (gases, small lipid soluble compounds: like dissolves like, water does not move across. Passive transport: does not require energy from the cell, materials move from a region of higher concentration to a region of lower concentration. Active transport: requires energy, molecules are moved from lower concentration to higher concentration.