Copyright © 2004 Pearson Education, Inc., publishing as Benjamin Cummings SECTION 3-5 How Things Get Into and Out of Cells
Copyright © 2004 Pearson Education, Inc., publishing as Benjamin Cummings The ease with which substances can cross the cell membrane Nothing passes through an impermeable barrier Anything can pass through a freely permeable barrier Cell membranes are selectively permeable Permeability
Copyright © 2004 Pearson Education, Inc., publishing as Benjamin Cummings Movement of a substance from an area of high concentration to low Continues until concentration gradient is eliminated Diffusion
Copyright © 2004 Pearson Education, Inc., publishing as Benjamin Cummings Figure 3.18 Diffusion Figure 3.18
Copyright © 2004 Pearson Education, Inc., publishing as Benjamin Cummings Figure 3.19 Diffusion across the Cell Membrane Figure 3.19
Copyright © 2004 Pearson Education, Inc., publishing as Benjamin Cummings Diffusion of water across a semipermeable membrane in response to solute differences Osmotic pressure = force of water movement into a solution Hydrostatic pressure opposes osmotic pressure Water molecules undergo bulk flow Osmosis
Copyright © 2004 Pearson Education, Inc., publishing as Benjamin Cummings Figure 3.20 Osmosis Figure 3.20
Copyright © 2004 Pearson Education, Inc., publishing as Benjamin Cummings The effects of osmotic solutions on cells Isotonic = no net gain or loss of water Hypotonic = net gain of water into cell Hemolysis Hypertonic = net water flow out of cell Crenation Tonicity
Copyright © 2004 Pearson Education, Inc., publishing as Benjamin Cummings Figure 3.21 Figure 3.21 Osmotic flow across a cell membrane
Copyright © 2004 Pearson Education, Inc., publishing as Benjamin Cummings Carrier mediated transport Binding and transporting specific ions by integral proteins Cotransport Counter-transport Facilitated diffusion Compounds to be transported bind to a receptor site on a carrier protein transport
Copyright © 2004 Pearson Education, Inc., publishing as Benjamin Cummings Figure 3.22 Facilitated Diffusion Figure 3.22
Copyright © 2004 Pearson Education, Inc., publishing as Benjamin Cummings Active transport Consumes ATP Independent of concentration gradients Types of active transport include Ion pumps Secondary active transport Active transport
Copyright © 2004 Pearson Education, Inc., publishing as Benjamin Cummings Figure 3.23 Figure 3.23 The Sodium Potassium Exchange Pump
Copyright © 2004 Pearson Education, Inc., publishing as Benjamin Cummings Figure 3.24 Figure 3.24 Secondary Active Transport
Copyright © 2004 Pearson Education, Inc., publishing as Benjamin Cummings Endocytosis is movement into the cell Receptor mediated endocytosis (coated vesicles) Pinocytosis Phagocytosis (pseudopodia) Exocytosis is ejection of materials from the cell Vesicular transport: material moves into or out of cells in membranous vesicles
Copyright © 2004 Pearson Education, Inc., publishing as Benjamin Cummings Figure 3.25 Receptor-Mediated Endocytosis Figure 3.25
Copyright © 2004 Pearson Education, Inc., publishing as Benjamin Cummings Figure 3.26 Pinocytosis and Phagocytosis Figure 3.26
Copyright © 2004 Pearson Education, Inc., publishing as Benjamin Cummings Difference in electrical potential between inside and outside a cell Undisturbed cell has a resting potential The transmembrane potential
Copyright © 2004 Pearson Education, Inc., publishing as Benjamin Cummings Fundamentals of Anatomy & Physiology SIXTH EDITION Frederic H. Martini PowerPoint ® Lecture Slide Presentation prepared by Dr. Kathleen A. Ireland, Biology Instructor, Seabury Hall, Maui, Hawaii Chapter 3, part 3 An Introduction to The Cellular Level of Organization
Copyright © 2004 Pearson Education, Inc., publishing as Benjamin Cummings SECTION 3-4 The Nucleus
Copyright © 2004 Pearson Education, Inc., publishing as Benjamin Cummings Surrounded by a nuclear envelope Perinuclear space Communicates with cytoplasm through nuclear pores The nucleus is the center of cellular operations
Copyright © 2004 Pearson Education, Inc., publishing as Benjamin Cummings Figure 3.13 The Nucleus Figure 3.13
Copyright © 2004 Pearson Education, Inc., publishing as Benjamin Cummings A supportive nuclear matrix One or more nucleoli Chromosomes DNA bound to histones Chromatin Contents of the nucleus
Copyright © 2004 Pearson Education, Inc., publishing as Benjamin Cummings Figure 3.14 Chromosome Structure Figure 3.14
Copyright © 2004 Pearson Education, Inc., publishing as Benjamin Cummings The cells information storage system Triplet code A gene contains all the triplets needed to code for a specific polypeptide The genetic code
Copyright © 2004 Pearson Education, Inc., publishing as Benjamin Cummings Gene activation initiates with RNA polymerase binding to the gene Transcription is the formation of mRNA from DNA mRNA carries instructions from the nucleus to the cytoplasm Gene activation and protein synthesis
Copyright © 2004 Pearson Education, Inc., publishing as Benjamin Cummings Figure 3.16 An overview of Protein Synthesis Figure 3.16
Copyright © 2004 Pearson Education, Inc., publishing as Benjamin Cummings A functional polypeptide is constructed using mRNA codons Sequence of codons determines the sequence of amino acids Complementary base pairing of anticodons (tRNA) provides the amino acids in sequence Translation is the formation of a protein
Copyright © 2004 Pearson Education, Inc., publishing as Benjamin Cummings Figure 3.17 The Process of Translation Figure 3.17
Copyright © 2004 Pearson Education, Inc., publishing as Benjamin Cummings Figure 3.17 The Process of Translation Figure 3.17
Copyright © 2004 Pearson Education, Inc., publishing as Benjamin Cummings SECTION 3-6 The Cell Life Cycle
Copyright © 2004 Pearson Education, Inc., publishing as Benjamin Cummings Cell division is the reproduction of cells Apoptosis is the genetically controlled death of cells Mitosis is the nuclear division of somatic cells Meiosis produces sex cells cell division
Copyright © 2004 Pearson Education, Inc., publishing as Benjamin Cummings Most somatic cells spend the majority of their lives in this phase Interphase includes G1 S G2 Interphase
Copyright © 2004 Pearson Education, Inc., publishing as Benjamin Cummings Figure 3.27 The Cell Life Cycle Figure 3.27
Copyright © 2004 Pearson Education, Inc., publishing as Benjamin Cummings Figure 3.28 DNA Replication Figure 3.28
Copyright © 2004 Pearson Education, Inc., publishing as Benjamin Cummings Prophase Metaphase Anaphase Telophase Mitosis, or nuclear division, has four phases During cytokinesis, the cytoplasm divides and cell division ends
Copyright © 2004 Pearson Education, Inc., publishing as Benjamin Cummings Figure 3.29 Interphase, Mitosis, and Cytokinesis Figure 3.29a-d
Copyright © 2004 Pearson Education, Inc., publishing as Benjamin Cummings Figure 3.29 Interphase, Mitosis, and Cytokinesis Figure 3.29e, f
Copyright © 2004 Pearson Education, Inc., publishing as Benjamin Cummings Generally, the longer the life expectancy of the cell, the slower the mitotic rate Stem cells undergo frequent mitoses Growth factors can stimulate cell division Abnormal cell division produces tumors or neoplasms Benign Malignant (invasive, and cancerous) Spread via metastasis Oncogenes Mitotic rate and cancer
Copyright © 2004 Pearson Education, Inc., publishing as Benjamin Cummings Process of specialization Results from inactivation of particular genes Produces populations of cells with limited capabilities Differentiated cells form tissues Differentiation
Copyright © 2004 Pearson Education, Inc., publishing as Benjamin Cummings The main points of the cell theory. The chief structural features of the cell membrane. The organelles of a typical cell, and their specific functions. The process of protein synthesis. The various transport mechanisms used by cells, and how this relates to the transmembrane potential. The cell life cycle, mitosis and cellular differentiation. You should now be familiar with: