Lecture Human anatomy and physiology - Chapter 3: Cells (part b)

Chapter 3 - Cells: The living units (part b). The main contents of this chapter include all of the following: Membrane transport: active processes, active transport, primary active transport, secondary active transport, vesicular transport, endocytosis and transcytosis,...and other contents.
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Lecture Human anatomy and physiology - Chapter 3: Cells (part b)Cells:TheLivingUnits:PartB Twotypesofactiveprocesses: ◦Activetransport ◦Vesiculartransport BothuseATPtomovesolutesacrossaliving plasmamembrane Requirescarrierproteins(solutepumps) Movessolutesagainstaconcentration gradient Typesofactivetransport: ◦Primaryactivetransport ◦Secondaryactivetransport EnergyfromhydrolysisofATPcausesshape changeintransportproteinsothatboundsolutes (ions)are“pumped”acrossthemembrane Sodiumpotassiumpump(Na+K+ATPase) ◦Locatedinallplasmamembranes ◦Involvedinprimaryandsecondaryactivetransportof nutrientsandions ◦Maintainselectrochemicalgradientsessentialfor functionsofmuscleandnervetissues Extracellular fluid Na+ Na+-K+ pump K+ Na+ bound ATP-binding site Cytoplasm 1 Cytoplasmic Na+ binds to pump protein. P ATP K+ released ADP 6 K+ is released from the pump protein 2 Binding of Na+ promotes and Na+ sites are ready to bind Na+ again. phosphorylation of the protein by ATP. The cycle repeats. Na+ released K+ bound P Pi K + 5 K+ binding triggers release of the 3 Phosphorylation causes the protein to phosphate. Pump protein returns to its change shape, expelling Na+ to the outside. original conformation. P 4 Extracellular K+ binds to pump protein.Copyright © 2010 Pearson Education, Inc. Figure 3.10 Extracellular fluid Na+ Na+-K+ pump ATP-binding site K+ Cytoplasm 1 Cytoplasmic Na+ binds to pump protein.Copyright © 2010 Pearson Education, Inc. Figure 3.10 step 1 Na+ bound P ATP ADP 2 Binding of Na+ promotes phosphorylation of the protein by ATP.Copyright © 2010 Pearson Education, Inc. Figure 3.10 step 2 Na+ released P 3 Phosphorylation causes the protein to change shape, expelling Na+ to the outside.Copyright © 2010 Pearson Education, Inc. Figure 3.10 step 3 K+ ...