Open AccessThe Osmotic Behavior of Corn Mitochondria
Author(s) -
George H. Lorimer,
R.H. Miller
Publication year - 1969
Publication title -
plant physiology
Language(s) - English
Resource type - Journals
SCImago Journal Rank - 3.554
H-Index - 312
eISSN - 1532-2548
pISSN - 0032-0889
DOI - 10.1104/pp.44.6.839
Subject(s) - osmotic pressure , osmotic concentration , mitochondrion , sucrose , isotonic , volume (thermodynamics) , biophysics , chemistry , diffusion , osmosis , swelling , biochemistry , biology , thermodynamics , materials science , membrane , medicine , physics , composite material
The volume changes undergone by corn (Zea mays L.) mitochondria suspended in solutions of constant or varying osmolarity were studied. Within the range of osmotic pressure from 1.8 to 8.4 atmospheres, corn mitochondria behave as osmometers, if allowance is made for an osmotic "dead space" of about 6.9 mul/mg protein. The final equilibrium volume of mitochondria swollen in solutions containing both ribose and sucrose were shown to depend upon the concentration of impermeable solute (sucrose) present and not upon the concentration of ribose present. Osmotic reversibility was found for mitochondria swollen in isotonic solutions of KCI or ribose. The passive swelling of corn mitochondria may be due to the osmotic flow of water coupled to the diffusion of a permeable solute.