BIOCH200 Lecture Notes - Atp Hydrolysis, Passive Transport, Homotrimer

• School: University of Alberta
• Department: Biochemistry
• Course: BIOCH200
• Professor: Walter Dixon

Document Summary

Lecture & start of: passive transport takes advantage of concentration gradient so it doesn"t take any energy or charge transfer, *porins and ion channels enable this via pore formation. *porins characterized by -barrels grouped together into a homotrimer: relatively non-selective. *ion channels are characterized by -helices arranged in a homotetramer: highly selective. *active transport transports molecules against their concentration gradient; requires energy: *two types: *energy source from established ion gradient that was created separately by atp hydrolysis. *[s] outside of cell need to reach vmax/2 = ktr. Na+/glucose transporter; sodium ions are brought into the cell along with glucose molecules. Secondary active transport: *antiport two different molecules transported across membrane in opposing directions. *usually, the two molecules are of the same charge to maintain membrane potential. * atpase makes it a given that this transporter is one that carries out primary active transport because atpase means that it hydrolyzes atp.