BIOL 1201 : Biology Exam 2
Document Summary
The problem: a cell and its environment, the interior of a cell is different than its environment, how to defend the internal environment but still communicate with the external environment, transport materials across the membrane. Integral membrane proteins: amphipathic, hydrophobic regions, hydrophilic regions. An optimal intermediate fluidity : not too solid, not too fluid, preserves membrane fuction, at the cell/body temperature, similar fluiditu in different species, species with a. Henrique and hansen 1901: raised pigs wearing underwear in a hot room, changed the properties of the subcutaneous fats, had a higher melting point, membrane fluidity can acclimate, membrane fluidity adjusted by changing. Increase unsaturated fats: increases the fluidity of the membrane. Movement of water across membranes: from high to low water potential. Diffusion: movement down a concentration gradient from high to low. Free energy: energy that"s free and available to do work. Gibbs (free) energy and chemical reactions: spontaneous, release gibbs energy (exergonic, non-spontaneous, requires gibbs energy (endergonic)
