4-Marieb_ch3b.pptx.pdf

3 PART B Cells and Tissues PowerPoint® Lecture Slide Presentation by Jerry L. Cook, Sam Houston University ESSENTIALS...

3 PART B Cells and Tissues PowerPoint® Lecture Slide Presentation by Jerry L. Cook, Sam Houston University ESSENTIALS OF HUMAN ANATOMY & PHYSIOLOGY EIGHTH EDITION ELAINE N. MARIEB Copyright © 2006 Pearson Education, Inc., publishing as Benjamin Cummings Cellular Physiology: Membrane Transport ▪ Membrane Transport – movement of substance into and out of the cell ▪ Transport is by two basic methods ▪ Passive transport ▪ No energy is required ▪ Active transport ▪ The cell must provide metabolic energy Copyright © 2006 Pearson Education, Inc., publishing as Benjamin Cummings Solutions and Transport ▪ Solution – homogeneous mixture of two or more components ▪ Solvent – dissolving medium ▪ Solutes – components in smaller quantities within a solution ▪ Intracellular fluid – nucleoplasm and cytosol ▪ Interstitial fluid – fluid on the exterior of the cell Copyright © 2006 Pearson Education, Inc., publishing as Benjamin Cummings Selective Permeability ▪ The plasma membrane allows some materials to pass while excluding others ▪ This permeability includes movement into and out of the cell Copyright © 2006 Pearson Education, Inc., publishing as Benjamin Cummings Passive Transport Processes ▪ Diffusion ▪ Particles tend to distribute themselves evenly within a solution ▪ Movement is from high concentration to low concentration, or down a concentration gradient PRESS TO PLAY DIFFUSION ANIMATION Figure 3.9 Copyright © 2006 Pearson Education, Inc., publishing as Benjamin Cummings Passive Transport Processes ▪ Types of diffusion ▪ Simple diffusion ▪ Unassisted process ▪ Solutes are lipid-soluble materials or small enough to pass through membrane pores Copyright © 2006 Pearson Education, Inc., publishing as Benjamin Cummings Passive Transport Processes ▪ Types of diffusion ▪ Osmosis – simple diffusion of water ▪ Highly polar water easily crosses the plasma membrane ▪ Facilitated diffusion ▪ Substances require a protein carrier for passive transport Copyright © 2006 Pearson Education, Inc., publishing as Benjamin Cummings Diffusion through the Plasma Membrane Figure 3.10 Copyright © 2006 Pearson Education, Inc., publishing as Benjamin Cummings Passive Transport Processes ▪ Filtration ▪ Water and solutes are forced through a membrane by fluid, or hydrostatic pressure ▪ A pressure gradient must exist ▪ Solute-containing fluid is pushed from a high pressure area to a lower pressure area Copyright © 2006 Pearson Education, Inc., publishing as Benjamin Cummings Active Transport Processes ▪ Transport substances that are unable to pass by diffusion ▪ They may be too large ▪ They may not be able to dissolve in the fat core of the membrane ▪ They may have to move against a concentration gradient ▪ Two common forms of active transport ▪ Solute pumping ▪ Bulk transport Copyright © 2006 Pearson Education, Inc., publishing as Benjamin Cummings Active Transport Processes ▪ Solute pumping ▪ Amino acids, some sugars and ions are transported by solute pumps ▪ ATP energizes protein carriers, and in most cases, moves substances against concentration gradients PRESS TO PLAY ACTIVE TRANSPORT ANIMATION Copyright © 2006 Pearson Education, Inc., publishing as Benjamin Cummings Active Transport Processes Figure 3.11 Copyright © 2006 Pearson Education, Inc., publishing as Benjamin Cummings Active Transport Processes ▪ Bulk transport ▪ Exocytosis ▪ Moves materials out of the cell ▪ Material is carried in a membranous vesicle ▪ Vesicle migrates to plasma membrane ▪ Vesicle combines with plasma membrane ▪ Material is emptied to the outside Copyright © 2006 Pearson Education, Inc., publishing as Benjamin Cummings Exocytosis Figure 3.12a Copyright © 2006 Pearson Education, Inc., publishing as Benjamin Cummings Active Transport Processes ▪ Bulk transport ▪ Endocytosis ▪ Extracellular substances are engulfed by being enclosed in a membranous vescicle ▪ Types of endocytosis ▪ Phagocytosis – cell eating ▪ Pinocytosis – cell drinking Copyright © 2006 Pearson Education, Inc., publishing as Benjamin Cummings Endocytosis Figure 3.13a Copyright © 2006 Pearson Education, Inc., publishing as Benjamin Cummings Cell Life Cycle ▪ Cells have two major periods ▪ Interphase ▪ Cell grows ▪ Cell carries on metabolic processes ▪ Cell division ▪ Cell replicates itself ▪ Function is to produce more cells for growth and repair processes Copyright © 2006 Pearson Education, Inc., publishing as Benjamin Cummings DNA Replication ▪ Genetic material duplicated and readies a cell for division into two cells ▪ Occurs toward the end of interphase ▪ DNA uncoils and each side serves as a template Figure 3.14 Copyright © 2006 Pearson Education, Inc., publishing as Benjamin Cummings Events of Cell Division ▪ Mitosis ▪ Division of the nucleus ▪ Results in the formation of two daughter nuclei ▪ Cytokinesis ▪ Division of the cytoplasm ▪ Begins when mitosis is near completion ▪ Results in the formation of two daughter cells Copyright © 2006 Pearson Education, Inc., publishing as Benjamin Cummings Stages of Mitosis ▪ Interphase ▪ No cell division occurs ▪ The cell carries out normal metabolic activity and growth ▪ Prophase ▪ First part of cell division ▪ Centromeres migrate to the poles Copyright © 2006 Pearson Education, Inc., publishing as Benjamin Cummings Stages of Mitosis ▪ Metaphase ▪ Spindle from centromeres are attached to chromosomes that are aligned in the center of the cell Copyright © 2006 Pearson Education, Inc., publishing as Benjamin Cummings Stages of Mitosis ▪ Anaphase ▪ Daughter chromosomes are pulled toward the poles ▪ The cell begins to elongate ▪ Telophase ▪ Daughter nuclei begin forming ▪ A cleavage furrow (for cell division) begins to form Copyright © 2006 Pearson Education, Inc., publishing as Benjamin Cummings Stages of Mitosis Figure 3.15 Copyright © 2006 Pearson Education, Inc., publishing as Benjamin Cummings Stages of Mitosis Figure 3.15(cont) Copyright © 2006 Pearson Education, Inc., publishing as Benjamin Cummings Protein Synthesis ▪ Gene – DNA segment that carries a blueprint for building one protein ▪ Proteins have many functions ▪ Building materials for cells ▪ Act as enzymes (biological catalysts) ▪ RNA is essential for protein synthesis Copyright © 2006 Pearson Education, Inc., publishing as Benjamin Cummings