BIOL 1107 Chapter Notes - Chapter 44: Osmoregulation, Tonicity, Osmotic Concentration
Document Summary
Ions sodium and calcium must stay at level that permits normal activity of muscles, neurons and body cells. Osmoregulation: animals control solute concentrations and balance water gain and loss. Dehydration environments cause animals to conserve body water. Marine birds and fishes eliminate salts to stay hydrated. Freshwater animals survive by absorbing salts from surroundings they conserve solutes. Since fresh water does not have them. Ammonia: toxic metabolites produced by nitrogenous molecules and nucleic acids. Excretion: body gets rid of nitrogenous metabolites and waste products. Osmoregulation balances the uptake and loss of water and solutes. Excessive water uptake animal cells swell/bursts. Substantial water loss animal cells shrivel/die. Concentration gradient: movement of water and solutes across plasma membrane. Hyperosmotic: high solute concentration and low free water concentration. Ex. salty lake cells shrivel up and die. Two solutions differ in osmolarity higher solute concentration. Hypoosmotic: low solute concentration and high free water concentration. Ex. blood cells swell and burst.
