BMS 360 Lecture Notes - Sodium Chloride, Exocytosis, Active Transport
Document Summary
Second transporter is coupled to primary (e. g. pump na+ in (downhill) while moving another molecule uphill) Energy of na+ leaking back into the cell used to move other molecule. In countertransport, a molecule is pulled out of the cell while another is moved downhill into the cell (or vice versa) Two molecules involved in countertransport move in opposite directions. Solute 1 m glucose, 1 osm 54. 5 m h2o. 1 m nacl, 2 osm 53. 5 m h2o. 1 m mgcl2, 3 osm 52. 5 m h2o. Osmolar shows moles of solute 1 m nacl 1 m na+, 1 m cl- = 2 m. Isotonic same concentration of nonpenetrating solutes on either side of membrane. Greater solute concentration outside hypertonic cell shrinks. Lower solute concentration outside hypotonic cell swells. Vesicle with solutes fuses with plasma membrane, disgorges solutes. E. g. nerve terminal neurotransmitters released into synaptic cleft.
