Cell Ultrastructure Pre-Lecture PDF

The dictionary is the only place that success comes before work. Hard work is the price we must pay for success. I think you can accomplish anything if you're willing to pay the price. -Vince Lombardi Fatigue makes cowards of us all. -Vince Lombardi CELL ULTRASTRUCTURE Dr. Michael J. Kern Object...

The dictionary is the only place that success comes before work. Hard work is the price we must pay for success. I think you can accomplish anything if you're willing to pay the price. -Vince Lombardi Fatigue makes cowards of us all. -Vince Lombardi CELL ULTRASTRUCTURE Dr. Michael J. Kern Objectives To orient you to the central dogma of cell biology and the problems cells face. To focus attention on subcellular structures and their function. To begin to appreciate the molecular composition and how it impacts the function of various subcellular structures. New Terms Replication Transcription Translation Eukaryotic Nucleus Cytoplasm Karyotype Plasma membrane Mitochondria sER-smooth Endoplasmic reticulum rER-rough Endoplasmic reticulum Golgi complex Cristae Lysosomes Peroxisomes Secretory granules Cytoskeleton Microtubules Microfilaments Intermediate filaments Microvilli Cilia Centriole Actin Tubulin Desmin Vimentin Cytokeratin neurofilaments  OUTLINE – I. Life’s Central Dogma – II. Problems Facing Cells – III. Eukaryotic Cell Structure classic view modern view specific subcellular features – IV. Prokaryotic Cell Structure I. Life’s Central Dogma replication transcription translation DNA RNA reverse transcription protein II. Problems Facing Cells A. Laws of Thermodynamics 1. Energy is conserved in any process; the energy gained by a system is exactly equal to the energy lost by the surroundings. 2. There is always an increase in Entropy in any naturally occurring process. B. Nutrition and energy 1.the capture of energy 2. the utilization of energy C. Sickness and disease III. Eukaryotic Cell Structure A. Classic view of eukaryotic cell structure B. Modern view of cell structure C. Major subcellular compartments III A. Classic view of eukaryotic cell structure - up until 1950s 1. cells were merely bags or sacs of protoplasm containing a nucleus with few generally accepted indications of an organized cytoplasm 2. the occurrence of granular and fibrillar structures within the protoplasm was viewed with great suspicion. However, both red blood cells and nucleated white blood cells were known to microscopists in the 19th century. Linear structures in muscle cells were also identified and isolated by microscopists in the 19th century. And the complex structure of neurons in brain was revealed by microscopists in the 19th century. III B. Modern view of cell structure 1. All cells are composed of innumerable small molecules and a few sets of macromolecules including: a. nucleic acids DNA & RNA c. polysaccharides Polymers of saccharides (sugars) b. proteins amino acids linked by peptide bonds d. lipids critical for cell membranes III B. Modern view of cell structure 2. The cell is a compartmentalized unit, not a homogeneous sac of chemicals use is made of membranes to define the limits of subcellular compartments where physiologic and biochemical events occur. III C. The Major Subcellular Compartments 1. the nucleus a. nuclear envelope/membrane b. nuclear skeleton c. chromatin d. nucleolus 2. the cytoplasm a. membrane limited components b. the microtrabecular network c. the cytosol lobulated vs oval nuclei nucleus Nucleus contains genetic material Chromosomes : classification - karyotype III C  2. The Cytoplasm a. membrane limited compartments The Plasma membrane limits the cell plasma membrane Do you know the name and function of these cells? Plasma membranes III. C. 2. The Cytoplasm a. membrane limited compartments i. mitochondria – “powerhouses of the cell” 1. generate ATP 2. generate CO2 and H2O as byproducts of ATP generation ii. endoplasmic reticulum 1. rough ER-protein secretion 2. smooth ER-steroid production iii. Golgi complex 1. secretory granules - hormones, enzymes 2. pigment granules - melanin granules iv. lysosomes – “recycle” organelles and degrade particles/pathogens v. peroxisomes – catabolize (breakdown) long chain fatty acids vi. vacuoles, secretory granules and vesicles 3-D Schematic of Eukaryotic Cell i. MITOCHONDRION cristae matrix i. MITOCHONDRION outer membrane cristae inner membrane ii. ROUGH ENDOPLASMIC RETICULUM nucleus rer rer ii. SMOOTH ENDOPLASMIC RETICULUM iii. the Golgi complex in a neuron Golgi complex nucleus iii. GOLGI COMPLEX iv. Lysosomes -neutrophil iv. LYSOSOMES v. PEROXISOME vi. secretory granules pituitary cells vi. Secretory granules-mast cell heparin, histamine granules vi. Secretory granules- goblet cell mucus granules nucleus vi. Cytoplasmic vesicles-adipocyte nucleus lipid droplet cytoplasm III C 2. The Cytoplasm b. the cytoskeleton (a.k.a microtrabecular network) i. microtubules - tubulins + MAPs ii. microfilaments - actin iii. intermediate filaments 1. cytokeratins - epithelial cells 2. desmin - muscle cells 3. vimentin - mesenchymal cells 4. GFAP - nerve supporting cells 5. neurofilaments - neurons the cytoskeleton (a.k.a. microtrabecular network) i. Microtubules-cilia Longitudinal section i. Microtubules-cilia cross sectioned doublets plasma membrane axoneme microtubules i. Microtubules basal body cilium basal body ciliary rootlet i. Microtubules- isolated mitotic spindle visualized using polarized light i. Microtubules- Centriole, microtubules and MTOCs i. Microtubules vs ii. microfilaments basal bodies, cilia and microvilli cilia microvilli basal bodies ii. microfilaments Longitudinal section of microvilli shows microfilaments ii. microfilaments cross section of microvilli shows microfilaments iii. intermediate filaments fluorescence microscopy III. C. The Major Subcellular Compartments 1. the nucleus 2. the cytoplasm a. membrane limited components b. the microtrabecular network c. the cytosol enzymes and other macromolecules (see BIOCHEMISTRY) IV. Prokaryotic Cell Structure Different than eukaryotic cell structure Prokaryotic Cells lack membrane-limited nucleus lack mitochondria and other compartments have a cell wall and a different cell membrane Similar to eukaryotic cell structure both contain ribosomes, DNA, RNA, and protein Bacterium -focus on this in Microbiology What should you know from this? What is life’s Central Dogma at the molecular level? Discuss cell compartmentalization and how it aids cell function. Name 4 subcellular organelles and one main function of each. Compare and contrast location, molecular composition and size of microtubules, microfilaments, and intermediate filaments. The cytoskeleton will be presented in the laboratory portion and expanded in a future lecture But we have one more item to discuss. 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