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Medical cell biology /

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Bibliographic Details
Other Authors: Goodman, Steven R.
Format: Book
Language:English
Published: Philadelphia, Pa. : Lippincott-Raven, [1998]
Edition:Second edition.
Subjects:
Cell Biology.
Molecular Biology.
Table of Contents:
  • Organization of the cell
  • Clinical case
  • Cell structure
  • The Cell is the smallest functional unit of tissues and organs, and eukaryotic cells contain organelles
  • Tools of the cell biologist
  • The Resolving power of a microscope is limited by the wavelength of the illuminating source
  • The Characteristics of light waves can be exploited for visualization of living cells
  • Tissues usually are fixed and stained for histologic examination
  • Individual proteins can be identified in cells using selective-staining procedures.
  • The Electron microscope permits analysis of fine ultrastructural detail
  • Samples for electron microscopy require special methods of preparation
  • Cell surface morphology can be studied with modified electron-microscopic procedures
  • Cell fractionation allows for the purification and analysis of individual organelles and proteins
  • Methods have been developed that permit the purification of individual proteins
  • Electrophoresis permits the size of a protein to be calculated
  • Mammalian cells can be studied by growing tissue preparations in a culture flask.
  • Cultured cells can also be used as systems for the study of physiologic processes, developmental events, and immune system activity
  • Pulse chase experiments are used to study important biomolecules in cells
  • Recombinant dna technology is revolutionizing the study of cells
  • Clinical case discussion
  • Cell membranes
  • Clinical case
  • Membrane structure
  • The Basic structure of biological membranes is a lipid bilayer
  • The Lipid composition of human and animal biological membranes includes phospholipids, cholesterol, and glycolipids.
  • Whereas membrane lipids form the foundation of the bilayer, membrane proteins are primarily responsible for function
  • Protein and lipids are asymmetrically distributed across biological membranes
  • Biological membranes are fluid, but that does not mean that every membrane macromolecule is mobile
  • Diffusion
  • The Cell membrane is a selective permeability barrier that maintains distinct internal and external cellular environments
  • Osmosis
  • Water can freely diffuse across membranes in the direction of lower to higher osmolarity.
  • Donnon effect and its relation to water flow
  • Transport
  • Multipass transmembrane proteins facilitate the diffusion of specific molecules across biological membranes
  • Active transport requires ATP hydrolysis, either directly or indirectly
  • Secondary active transport involves the cotransport of a molecule with sodium as it moves down its electrochemical gradient
  • Antiport of sodium and calcium ions plays an important role in cardiac muscle contraction
  • ABC transporters are a distinct class of atpase
  • Ion channels and membrane potentials.
  • Protein channels permit the rapid flux of ions across membranes
  • Ion channels have a common structural motif: the transmembrane A-helix
  • Ion channels are allosteric proteins, the conformation of which is regulated by different types of stimuli
  • Structural studies provide insight concerning channel-gating mechanisms
  • Pore size and charge interactions determine the ion selectivity of channels
  • Membrane potential is caused by a difference of electric charge on the two sides of the plasma membrane.
  • Membrane potential for any cell at rest depends primarily on the transmembrane potassium ion gradient through nongated potassium ion leak channels
  • Resting membrane potential is maintained by sodium/potassium ATPase
  • Action potentials
  • Transmembrane electrical signals not conveyed as action potentials are limited by the intracellular distance they can travel
  • Voltage-gated sodium and potassium ion channels make cells electrically excitable
  • Action potentials travel long distances without decrement
  • Two factors accelerate the velocity of an action potential: axonal caliber and myelin
  • Clinical case discussion
  • Cytoskeleton.
  • Clinical case
  • Microfilaments
  • Actin-based cytoskeletal structures were first described in muscle tissue
  • Skeletal muscle is formed from bundles of muscle fibers
  • The Functional unit of skeletal muscle is the sarcomere
  • Thin filaments are built from the proteins actin, tropomyosin, and troponin
  • Thick filaments are composed of the protein myosin
  • Accessory proteins are responsible for maintenance of myofibril architecture
  • Muscle contraction involves the sliding of the thick and thin filaments relative to each other in the sarcomere.
  • Adenosine triphosphate hydrolysis is necessary for cross-bridge interactions with thin filaments
  • Calcium regulation of skeletal muscle contraction is mediated by troponin and tropomyosin
  • Intracellular calcium in skeletal muscle is regulated by a specialized membrane campartment, the sarcoplasmic reticulum
  • There are three types of muscle tissue
  • Myocardial tissue: striated muscle built from individual cells
  • The Contractile apparatus of cardiac muscle is similar to that of skeletal muscle
  • The Smooth muscle cell does not contain sarcomeres.
  • The Contractile apparatus of smooth muscle contains actin and myosin
  • Smooth-muscle contraction occurs via myosin-based calcium ion regulatory mechanisms
  • Smooth-muscle contraction is influenced at multiple levels
  • Actin-myosin contractile structures are found in nonmuscle cells
  • Bundles of F-actin form a structural support for the microvilli of epithelial cells
  • The Gel-sol state of the cortical cytoplasm is controlled by the dynamic status of actin
  • The Spectrin membrane skeleton.
  • The Erythrocyte spectrin membrane skeleton's structure and function is understood in exquisite detail
  • We now know that spectrin is an ubiquitous component of nonerythroid cells
  • Spectrins I and II, A-actinin, and dystrophinform the spectrin supergene family of actin-binding proteins
  • Intermediate filaments
  • A Heterogeneous group of proteins form intermediate filaments in various cells
  • How can such a heterogeneous group of proteins all form intermediate filaments?
  • Microtubules
  • Microtubules are polymers composed of tubulin
  • Microtubules undergo rapid assembly and disassembly.
  • By capping the minus ends of microtubules, the centrosome acts as a microtubule-organizing center
  • The Behavior of cytoplasmic microtubules can be regulated
  • Microtubules are involved in intracellular vesicle and organelle transport
  • Cilia and flagella are specialized organelles composed of microtubules
  • Axonemal microtubules are stable
  • Microtubule sliding results in axonemal motility
  • The Neuronal cytoskeleton
  • The Shape of neurons is determined by their cytoskeleton
  • Neuronal metabolism requires stable and dynamically unstable filamentous structures
  • Accessory proteins of the neuronal cytoskeleton are functionally diverse.
  • Organelle structure and function
  • Regulation of gene expression
  • Cell adhesion and the extracellular matrix
  • Intercellular signaling
  • Signal transduction events
  • Cell division
  • Cell motility.