Out of the following steps the one which is passive and does not depend on ATP distribution is:
Ans: b (H2O entry via osmosis) Ref: Ganong, 23rd edi., Pg. 46Ref: Ganong, 23rd edi., Pg. 46Osmosis does not need energy ie. not dependant on ATP distributionActive transport Simple diffusionEnergy is required It is a passive process - noATP required Against electrochemical Along electrochemical gradient gradientUnidirectional Bidirectional Carrier proteins are required, Carrier proteins are not so it is saturable, has Vmax required, so it is not (ie transport maximum) saturable and has no Vmax (ie transport maximum) Eg: Na+ K+ pump Eg: diffusion of gases in lungs Note: Endocytosis is an energy requiring processFacilitated diffusionIt is a passive process. Along electrochemical gradient Unidirectional or bidirectional Carrier proteins are required, so it is saturable, has Vmax (i.e. transport maximum) Eg: Glucose uptake by muscles
Na+ cotransport with molecules
H2O entry via osmosis
Na+ exit & K+ entry into cell
Uptake of molecule by endocytosis
General