BIOL 201 Lecture Notes - Lecture 3: Mass Diffusivity, Atp Hydrolysis, Thermal Energy
Document Summary
Magnitudes of energy in cells: atp hydrolysis -7. 3 kcal/mol. Thermal energy random molecule collision: baseline for cellular energy scales, e=(3/2)kbt. 1 kbt=0. 6 kcal/mol (thermal energy of a molecule: atp hydrolysis produces around 20kbt (physiological conditions, 1 m concentration, molecule brownian motion contributes to diffusion. Diffusion coefficient d (smaller molecule, larger d, diffuse faster) Due to random walk the mean displacement of all molecules = 0 (most molecules return to the origin) A few made further to the sides -mean squared displacement x2=2dt (in 3 dimension displacement = radio distance) (vector calculation) Other energies relevant to cells: cell function in a range that energies such as electromagnetic, mechanical, thermal energies, are all balanced, mechanical energy. Cells and subcellular structures both feel and produce mechanical forces eg. microtubules changes shape in respond to forces in cells. 1kbt=4. 1 pn nm: electromagnetic energy (light) Eg. cells absorb photons during photosynthesis eg. fireflies produce light.
