PowerPoint ® Lecture Slide Presentation prepared by Dr. Kathleen A. Ireland, Biology Instructor, Seabury Hall, Maui, Hawaii An Introduction to The Cellular Level of Organization
Copyright © 2004 Pearson Education, Inc., publishing as Benjamin Cummings Learning Objectives List the main points of the cell theory. Describe the chief structural features of the cell membrane. Describe the organelles of a typical cell, and give their specific functions. Summarize the process of protein synthesis. Describe the various transport mechanisms used by cells, and relate this to the transmembrane potential. Describe the cell life cycle, mitosis and cellular differentiation.
Copyright © 2004 Pearson Education, Inc., publishing as Benjamin Cummings SECTION 3-1 An Introduction to Cells
Copyright © 2004 Pearson Education, Inc., publishing as Benjamin Cummings Cells are the building blocks of all plants and animals Cells are produced by the division of preexisting cells Cells are the smallest units that perform all vital physiological functions Each cell maintains homeostasis at the cellular level Homeostasis at higher levels reflects combined, coordinated action of many cells The cell theory states:
Copyright © 2004 Pearson Education, Inc., publishing as Benjamin Cummings Figure 3.1 Figure 3.1 The Diversity of Cells in the Human Body
Copyright © 2004 Pearson Education, Inc., publishing as Benjamin Cummings Cytology, the study of the structure and function of cells The human body contains both somatic and sex cells Cell biology
Copyright © 2004 Pearson Education, Inc., publishing as Benjamin Cummings Figure 3.2 The Anatomy of a Representative Cell Figure 3.2
Copyright © 2004 Pearson Education, Inc., publishing as Benjamin Cummings Is surrounded by extracellular fluid, which is the interstitial fluid of the tissue Has an outer boundary called the cell membrane or plasma membrane A typical cell
Copyright © 2004 Pearson Education, Inc., publishing as Benjamin Cummings SECTION 3-2 The Cell Membrane
Copyright © 2004 Pearson Education, Inc., publishing as Benjamin Cummings Physical isolation Regulation of exchange with the environment Structural support Cell membrane functions include:
Copyright © 2004 Pearson Education, Inc., publishing as Benjamin Cummings The cell membrane is a phospholipid bilayer with proteins, lipids and carbohydrates. Figure 3.3 The Cell Membrane Figure 3.3
Copyright © 2004 Pearson Education, Inc., publishing as Benjamin Cummings Integral proteins Peripheral proteins Anchoring proteins Recognition proteins Receptor proteins Carrier proteins Channels Membrane proteins include:
Copyright © 2004 Pearson Education, Inc., publishing as Benjamin Cummings Figure 3.4 Membrane proteins Figure 3.4
Copyright © 2004 Pearson Education, Inc., publishing as Benjamin Cummings Proteoglycans Glycolipids Glycoproteins Membrane carbohydrates form the glycocalyx
Copyright © 2004 Pearson Education, Inc., publishing as Benjamin Cummings SECTION 3-3 The Cytoplasm
Copyright © 2004 Pearson Education, Inc., publishing as Benjamin Cummings The fluid (cytosol) The organelles the cytosol surrounds The cytoplasm contains:
Copyright © 2004 Pearson Education, Inc., publishing as Benjamin Cummings Nonmembranous organelles are not enclosed by a membrane and always in touch with the cytosol Cytoskeleton, microvilli, centrioles, cilia, ribosomes, proteasomes Membranous organelles are surrounded by lipid membranes Endoplasmic reticulum, Golgi apparatus, lysosomes, peroxisomes, mitochondria Organelles
Copyright © 2004 Pearson Education, Inc., publishing as Benjamin Cummings Figure 3.2 The Anatomy of a Representative Cell Figure 3.2
Copyright © 2004 Pearson Education, Inc., publishing as Benjamin Cummings Microfilaments Intermediate filaments Microtubules Thick filaments Microvilli increase surface area Cytoskeleton provides strength and flexibility
Copyright © 2004 Pearson Education, Inc., publishing as Benjamin Cummings Figure 3.5 The Cytoskeleton Figure 3.5
Copyright © 2004 Pearson Education, Inc., publishing as Benjamin Cummings Direct the movement of chromosomes during cell division Organize the cytoskeleton Cytoplasm surrounding the centrioles is the centrosome Centrioles
Copyright © 2004 Pearson Education, Inc., publishing as Benjamin Cummings Is anchored by a basal body Beats rhythmically to move fluids across cell surface Cilia
Copyright © 2004 Pearson Education, Inc., publishing as Benjamin Cummings Figure 3.6 Centrioles and Cilia Figure 3.6
Copyright © 2004 Pearson Education, Inc., publishing as Benjamin Cummings Are responsible for manufacturing proteins Are composed of a large and a small ribosomal subunit Contain ribosomal RNA (rRNA) Can be free or fixed ribosomes Ribosomes
Copyright © 2004 Pearson Education, Inc., publishing as Benjamin Cummings Figure 3.7 Ribosomes Figure 3.7
Copyright © 2004 Pearson Education, Inc., publishing as Benjamin Cummings Remove and break down damaged or abnormal proteins Require targeted proteins to be tagged with ubiquitin Proteasomes
Copyright © 2004 Pearson Education, Inc., publishing as Benjamin Cummings Intracellular membranes involved in synthesis, storage, transportation and detoxification Forms cisternae Rough ER (RER) contains ribosomes Forms transport vesicles Smooth ER (SER) Involved in lipid synthesis Endoplasmic reticulum
Copyright © 2004 Pearson Education, Inc., publishing as Benjamin Cummings Figure 3.8 The Endoplasmic Reticulum Figure 3.8
Copyright © 2004 Pearson Education, Inc., publishing as Benjamin Cummings Forms secretory vesicles Discharged by exocytosis Forms new membrane components Packages lysosomes Golgi Apparatus
Copyright © 2004 Pearson Education, Inc., publishing as Benjamin Cummings Figure 3.9 The Golgi Apparatus Figure 3.9
Copyright © 2004 Pearson Education, Inc., publishing as Benjamin Cummings Figure 3.10 Functions of the Golgi Apparatus Figure 3.10
Copyright © 2004 Pearson Education, Inc., publishing as Benjamin Cummings Lysosomes are Filled with digestive enzymes Responsible for autolysis of injured cells Peroxisomes Carry enzymes that neutralize toxins Lysosomes and Peroxisomes
Copyright © 2004 Pearson Education, Inc., publishing as Benjamin Cummings Figure 3.11 Lysosome Functions Figure 3.11
Copyright © 2004 Pearson Education, Inc., publishing as Benjamin Cummings Continuous movement and recycling of membranes ER Vesicles Golgi apparatus Cell membrane Membrane flow
Copyright © 2004 Pearson Education, Inc., publishing as Benjamin Cummings Responsible for ATP production through aerobic respiration Matrix = fluid contents of mitochondria Cristae = folds in inner membrane Mitochondria
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 3-5 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 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: