Copyright © 2004 Pearson Education, Inc., publishing as Benjamin Cummings Human Anatomy & Physiology, Sixth Edition Elaine N. Marieb PowerPoint ® Lecture Slides prepared by Vince Austin, University of Kentucky 3 Cells: The Living Units Part B Modified by Brian Fedigan

Copyright © 2004 Pearson Education, Inc., publishing as Benjamin Cummings Active Transport  Uses ATP (It is an energy source produced during photosynthesis and cellular respiration and consumed by many enzymes and a multitude of cellular processes) to move solutes across a membrane photosynthesiscellular respirationenzymes  Requires carrier proteins Active Transport PLAY

Copyright © 2004 Pearson Education, Inc., publishing as Benjamin Cummings Types of Active Transport  Symport system – two substances are moved across a membrane in the same direction  Antiport system – two substances are moved across a membrane in opposite directions

Copyright © 2004 Pearson Education, Inc., publishing as Benjamin Cummings Types of Active Transport  Primary active transport – hydrolysis (Hydrolysis is a chemical reaction during which one or more water molecules are split into hydrogen and hydroxide ions) of ATP phosphorylates the transport protein causing conformational changechemical reactionwater moleculeshydrogenhydroxide  Secondary active transport – use of an exchange pump (such as the Na + -K + pump) indirectly to drive the transport of other solutes

Copyright © 2004 Pearson Education, Inc., publishing as Benjamin Cummings Types of Active Transport Figure 3.11

Copyright © 2004 Pearson Education, Inc., publishing as Benjamin Cummings Vesicular Transport  Transport of large particles and macromolecules across plasma membranes  Exocytosis – moves substance from the cell interior to the extracellular space  Endocytosis – enables large particles and macromolecules to enter the cell

Copyright © 2004 Pearson Education, Inc., publishing as Benjamin Cummings Passive Membrane Transport – Review ProcessEnergy SourceExample Simple diffusionKinetic energyMovement of O 2 through membrane Facilitated diffusionKinetic energyMovement of glucose into cells OsmosisKinetic energyMovement of H 2 O in & out of cells FiltrationHydrostatic pressureFormation of kidney filtrate

Copyright © 2004 Pearson Education, Inc., publishing as Benjamin Cummings Active Membrane Transport – Review ProcessEnergy SourceExample Active transport of solutesATP Movement of ions across membranes ExocytosisATPNeurotransmitter secretion EndocytosisATPWhite blood cell phagocytosis Fluid-phase endocytosisATPAbsorption by intestinal cells Receptor-mediated endocytosisATPHormone and cholesterol uptake Endocytosis via caveoliATPCholesterol regulation Endocytosis via coatomer vesicles ATP Intracellular trafficking of molecules

Copyright © 2004 Pearson Education, Inc., publishing as Benjamin Cummings Cytoplasm  Cytoplasm – material between plasma membrane and the nucleus  Cytoplasmic organelles – metabolic machinery of the cell  Inclusions – chemical substances such as glycosomes, glycogen granules, and pigment

Copyright © 2004 Pearson Education, Inc., publishing as Benjamin Cummings Cytoplasmic Organelles  Specialized cellular compartments  Membranous  Mitochondria, peroxisomes, lysosomes, endoplasmic reticulum, and Golgi apparatus  Nonmembranous  Cytoskeleton, centrioles, and ribosomes

Copyright © 2004 Pearson Education, Inc., publishing as Benjamin Cummings Mitochondria  Double membrane structure with shelflike cristae  Provide most of the cell’s ATP via aerobic cellular respiration  Contain their own DNA and RNA

Copyright © 2004 Pearson Education, Inc., publishing as Benjamin Cummings Mitochondria Figure 3.17

Copyright © 2004 Pearson Education, Inc., publishing as Benjamin Cummings Ribosomes  Granules containing protein and rRNA  Site of protein synthesis

Copyright © 2004 Pearson Education, Inc., publishing as Benjamin Cummings Endoplasmic Reticulum (ER)  Interconnected tubes and parallel membranes enclosing cisternae  Continuous with the nuclear membrane  Two varieties – rough ER and smooth ER

Copyright © 2004 Pearson Education, Inc., publishing as Benjamin Cummings Endoplasmic Reticulum (ER) Figure 3.18a and c

Copyright © 2004 Pearson Education, Inc., publishing as Benjamin Cummings Rough (ER)  External surface studded with ribosomes  Manufactures all secreted proteins  Responsible for the synthesis of integral membrane proteins and phospholipids for cell membranes

Copyright © 2004 Pearson Education, Inc., publishing as Benjamin Cummings Smooth ER  Tubules arranged in a looping network  Catalyzes the following reactions in various organs of the body  In the liver – lipid and cholesterol metabolism, breakdown of glycogen and, along with the kidneys, detoxification of drugs  In the testes – synthesis of steroid-based hormones  In the intestinal cells – absorption, synthesis, and transport of fats  In skeletal and cardiac muscle – storage and release of calcium