Copyright © The McGraw-Hill Companies, Inc. Permission required for reproduction or display. 2-1 Human Genetics Concepts and Applications Eighth Edition Powerpoint Lecture Outline Ricki Lewis Prepared by Dubear Kroening University of Wisconsin-Fox Valley

Copyright © The McGraw-Hill Companies, Inc. Permission required for reproduction or display. 2-2 Chapter 2 Cells

Copyright © The McGraw-Hill Companies, Inc. Permission required for reproduction or display. 2-3 Cells The Basic Unit of Life Organisms can be single cells or collections of many cells Mutations affect whether the cell functions normally Cell numbers are important, critical to growth, development, and healing

Copyright © The McGraw-Hill Companies, Inc. Permission required for reproduction or display. 2-4 Human Cells > 260 cell types Four categories – Epithelial – Muscle – Nerve – Connective

Copyright © The McGraw-Hill Companies, Inc. Permission required for reproduction or display. 2-5 Types of Cells Prokaryotic cells Lack a nucleus Eukaryotic cells Contain a nucleus and complex organelles Figure 2.2

Copyright © The McGraw-Hill Companies, Inc. Permission required for reproduction or display. 2-6 Domains of Life Genetic material Domain in a compartment? Example Bacteria no (prokaryote) E. coli Archaea no (prokaryote) Methanopyrus Eukarya yes (eukaryote) amoeba, plant, human

Copyright © The McGraw-Hill Companies, Inc. Permission required for reproduction or display. 2-7 Macromolecules in Cells Carbohydratessugars, starches energy Lipidsfats, oilsmembranes Proteinsmyosin, collagenstructures, enzymes Nucleic acidsDNA, RNAgenetic material

Copyright © The McGraw-Hill Companies, Inc. Permission required for reproduction or display. 2-8 An Animal Cell Surrounded by the plasma membrane Contains a nucleus and cytoplasm with specialized organelles Figure 2.3

Copyright © The McGraw-Hill Companies, Inc. Permission required for reproduction or display. 2-9 Structures and Functions of Organelles Table 2.1

Copyright © The McGraw-Hill Companies, Inc. Permission required for reproduction or display The Nucleus Surrounded by double layered nuclear membrane Contains – Nuclear pores that allow movement of some molecules in and out – Nucleolus, which is the site of RNA production –Chromosomes composed of DNA and proteins

Copyright © The McGraw-Hill Companies, Inc. Permission required for reproduction or display Figure 2.3 Figure 2.4

Copyright © The McGraw-Hill Companies, Inc. Permission required for reproduction or display Secretion Figure 2.5

Copyright © The McGraw-Hill Companies, Inc. Permission required for reproduction or display Endoplasmic Reticulum (ER) Interconnected membranous tubules and sacs Rough ER contains ribosomes, site of protein synthesis Smooth ER does not contain ribosomes and is important in lipid synthesis Figure 2.3

Copyright © The McGraw-Hill Companies, Inc. Permission required for reproduction or display Golgi Apparatus Final protein folding Stores secreted material Forms sugars, glycoproteins, and glycolipids Vesicles of material are released Figure 2.3

Copyright © The McGraw-Hill Companies, Inc. Permission required for reproduction or display Lysosomes Break down bacteria, cellular debris, and nutrients Contain > 40 types of digestive enzymes Tay-Sachs is an inherited lysosomal storage disorder Figure 2.6

Copyright © The McGraw-Hill Companies, Inc. Permission required for reproduction or display Peroxisomes Contain several types of enzymes Break down lipids, rare biochemicals Synthesize bile acids Detoxify compounds from free radicals Abundant in liver and kidney cells

Copyright © The McGraw-Hill Companies, Inc. Permission required for reproduction or display Mitochondria Site of ATP (energy) production Has its own circular DNA Mitochondrial genes are inherited from the mother Figure 2.7

Copyright © The McGraw-Hill Companies, Inc. Permission required for reproduction or display Plasma Membrane Selectively permeable A phospholipid bilayer forms a hydrophobic barrier Contains proteins, glycoproteins, and glycolipids Important to cell function and interactions May be receptors Form channels for ions Figure 2.8

Copyright © The McGraw-Hill Companies, Inc. Permission required for reproduction or display Figure 2.9

Copyright © The McGraw-Hill Companies, Inc. Permission required for reproduction or display Faulty Ion Channels May Cause Inherited Diseases Sodium channels – ability to detect pain Potassium channels – Long-QT syndrome Chloride channels – cystic fibrosis

Copyright © The McGraw-Hill Companies, Inc. Permission required for reproduction or display Cytoskeleton Fibers, filaments, and their associated proteins Dynamic Functions: Maintain cell shape Connect cells to each other Transport organelles and small molecules Provide cell motility (some cell types) Move chromosomes in cell division Compose cilia

Copyright © The McGraw-Hill Companies, Inc. Permission required for reproduction or display Cytoskeleton Figure 2.10

Copyright © The McGraw-Hill Companies, Inc. Permission required for reproduction or display Cell Division and Death Are required for normal growth and development. Mitosis produces new cells –Mitosis occurs in somatic cells (all cells but egg and sperm) Apoptosis is cell death that is part of normal development Necrosis is cell death in response to injury

Copyright © The McGraw-Hill Companies, Inc. Permission required for reproduction or display Figure 2.12

Copyright © The McGraw-Hill Companies, Inc. Permission required for reproduction or display The Cell Cycle The sequence of events associated with cell division S phase: DNA synthesis G phase: gap for growth M phase: mitosis (nuclear division) Cell division or cytokinesis follows Figure 2.13

Copyright © The McGraw-Hill Companies, Inc. Permission required for reproduction or display Stages of the Cell Cycle Interphase –Prepares for cell division –Replicates DNA and subcellular structures –Composed of G 1, S, and G 2 –Cells may progress to mitosis or enter G 0, a quiescent phase Mitosis division of the nucleus Cytokinesis division of the cytoplasm

Copyright © The McGraw-Hill Companies, Inc. Permission required for reproduction or display Replication of Chromosomes Process of duplicating a chromosome Occurs prior to division, during S of interphase Produces sister chromatids Held together at centromere Figure 2.14

Copyright © The McGraw-Hill Companies, Inc. Permission required for reproduction or display Mitosis Produces two identical daughter cells Replicated chromosomes align Sister chromatids separate and move to opposite poles. Nuclear membranes form around each new nucleus Division of cytoplasm or cytokinesis occurs.

Copyright © The McGraw-Hill Companies, Inc. Permission required for reproduction or display Overview of Mitosis Continuous process divided into Prophase Metaphase Anaphase Telophase

Copyright © The McGraw-Hill Companies, Inc. Permission required for reproduction or display Mitosis in a Human Cell Figure 2.15

Copyright © The McGraw-Hill Companies, Inc. Permission required for reproduction or display Prophase Replicated chromosomes condense Microtubules organize into a spindle Nuclear membrane breaks down Figure 2.15

Copyright © The McGraw-Hill Companies, Inc. Permission required for reproduction or display Metaphase Chromosomes line up on the metaphase plate Spindle microtubules are attached to centromeres of chromosomes Figure 2.15

Copyright © The McGraw-Hill Companies, Inc. Permission required for reproduction or display Anaphase Centromeres divide Chromosomes move to opposite ends of the cell Figure 2.15

Copyright © The McGraw-Hill Companies, Inc. Permission required for reproduction or display Telophase Chromosomes uncoil Nuclear membranes form Spindle disappears Figure 2.15

Copyright © The McGraw-Hill Companies, Inc. Permission required for reproduction or display Cytokinesis Cytoplasmic division occurs after nuclear division is complete. Two cells are formed.

Copyright © The McGraw-Hill Companies, Inc. Permission required for reproduction or display Cell Cycle Control Proteins called “checkpoint proteins” monitor progression through the cell cycle. Figure 2.16

Copyright © The McGraw-Hill Companies, Inc. Permission required for reproduction or display Telomeres Located at the ends of the chromosomes Contain hundreds to thousands of six nucleotide repeats Most cells lose repeats after each cell division After about 50 divisions, shortened telomeres signal the cell to stop dividing Sperm, eggs, bone marrow, and cancer cells produce telomerase that prevent shortening of telomere

Copyright © The McGraw-Hill Companies, Inc. Permission required for reproduction or display Apoptosis Orderly destruction, stepwise process –Caspases destroy cellular components, signal phagocytes to clean up Mitosis and apotosis work together to form functional body Cancer can result from too much mitosis, too little apotosis

Copyright © The McGraw-Hill Companies, Inc. Permission required for reproduction or display Apoptosis Programmed cell death is part of normal development Figure 2.18

Copyright © The McGraw-Hill Companies, Inc. Permission required for reproduction or display Cell-Cell Interaction: Signal Transduction The process of transmitting a signal from the environment to a cell Figure 2.19

Copyright © The McGraw-Hill Companies, Inc. Permission required for reproduction or display Signal Transduction Receptor binds to messenger Interacts with regulator Causes enzyme to produce second messenger Activates enzymes Amplification due to cascade Defects cause disease

Copyright © The McGraw-Hill Companies, Inc. Permission required for reproduction or display Cell-Cell Interactions: Cell Adhesion Molecules (CAMs) Figure 2.20

Copyright © The McGraw-Hill Companies, Inc. Permission required for reproduction or display Stem Cells and Cell Specialization Stem cells and progenitor cells renew tissues Retain the ability to divide and specialize Described in terms of potential –Totipotent –Pluripotent

Copyright © The McGraw-Hill Companies, Inc. Permission required for reproduction or display Figure 2.22

Copyright © The McGraw-Hill Companies, Inc. Permission required for reproduction or display Medical Treatments Using Stem Cells Regenerative medicine Sources of stem cells –Early embryos from fertility clinics –Somatic cell nuclear transfer –Tissue-based (adult) stem cells Ethical issues associated with use of embryos

Copyright © The McGraw-Hill Companies, Inc. Permission required for reproduction or display Figure 2.24