Cell Biology Review Part 1 PDF

Cell Biology Review 1 UNITS VETS10018 Animal Systems and Professional Life 1 VETS10021 Principles and Practice of Veterinary Nursing VETS10022 Animal Health and the Veterinary Profession Dr Dominic Harrison BVSc MRCVS Lecturer in Veterinary Pathology, Veterinary Investigations...

Cell Biology Review 1 UNITS VETS10018 Animal Systems and Professional Life 1 VETS10021 Principles and Practice of Veterinary Nursing VETS10022 Animal Health and the Veterinary Profession Dr Dominic Harrison BVSc MRCVS Lecturer in Veterinary Pathology, Veterinary Investigations Officer Email: [email protected]  Cell Biology Review UNITS VETS10018 Animal Systems and Professional Life 1 VETS10021 Principles and Practice of Veterinary Nursing VETS10022 Animal Health and the Veterinary Profession Dr Dominic Harrison BVSc MRCVS Lecturer in Veterinary Pathology, Veterinary Investigations Officer Email: [email protected] Learning Objectives 1) Cell structure Describe the major structural components of the cell Outline the structure and function of the cytoplasm and its organelles Explain the structure and function of the cell nucleus 2) Cell division Outline the process of eukaryotic cell division and its regulation 3) Cell membrane structure and biology Describe the structure and function of the plasma membrane including how transport across the membrane is regulated Outline the structural-functional relationships of a number of different cell types Further reading  What are cells? Structural and functional units of all living things Prokaryotic cells – bacteria Eukaryotic cells – animal and plant cells, generally larger than prokaryotes with a nucleus and membrane-bound organelles with specific functions Viruses are not cells and are not classed as living organisms  ILO: 1 Eukaryotic cell overview Cell membrane (Plasma membrane) Cytoskeleton Nucleus Mitochondria Nucleolus Ribosome Lysosomes s Rough and Smooth Endoplasmic Reticulum Cytoplas m& Cytosol Golgi Body  ILO: 1 Eukaryotic cell structure and function  ILO: 1 Functions of cellular structures – Cell membrane Fluidic phospholipid bilayers that enclose cells and their organelles. First contact with harmful substances, agents, and infectious microbes. Two main functions: 1) Serve as selective barriers. 2) Forms a structural base for the membrane associated proteins (enzymes and receptors) that determine cell function.  ILO: 1 Functions of cellular structures – Cytoplasm & Cytosol Cytoplasm Portion of the cell that is inside the plasma membrane and outside the nuclear envelope. Cytosol Fluid portion of the cytoplasm that surrounds organelles. It contains: Water Dissolved ions Macromolecules such as proteins. Cytosol – A molecular ILO: 1 soup Simulation of dynamic molecular model of the bacterial cytoplasm Sean McGuffee, Adrian Elcock (2011) CIL:28235, Escherichia coli. CIL. Dataset. https://doi.org/doi:10.7295/W9CIL28235  ILO: 1 Functions of cellular structures - Cytoskeleton Intracellular scaffolding of proteins that allows cells to: Adopt a particular shape Maintain polarity Organise intracellular organelles Move Three major classes of cytoskeletal proteins: I. Intermediate filaments – position nucleus II. Actin microfilaments – structural support III. Microtubules – transport and mitosis Actin filaments in a human fibroblast Microtubules in an epithelial cell undergoing mitosis (pig) Don W. Fawcett, Elias Lazarides (2011) Nasser Rusan, 2005 Olympus CIL:36067 BioScapes Competition (2012) CIL:42513  ILO: 1 Functions of cellular structures – Ribosomes & Endoplasmic Reticulum Functions of cellular structures – ILO: 1 Ribosomes Made of ribosomal RNA proteins. Facilitate translation; the synthesis of proteins by converting genetic information encoded in messenger RNA (mRNA) into polypeptide chains of amino acids that make up proteins. Two types of ribosomes 1. Free ribosomes are in the cytosol and can move throughout the cell. 2. Fixed ribosomes are attached to the membrane of the rough Endoplasmic Reticulum (rER). Nucleus and rER of acinar cell (Little Brown Bat) Don W. Fawcett (2011) CIL:10763 Functions of cellular structures - ILO: 1 Endoplasmic reticulum Rough Endoplasmic Reticulum (rER) Membrane-bound network of flattened sack-like cisternae that communicate with the nuclear envelope. Attached ribosomes impart a rough appearance. Function Protein synthesis Smooth Endoplasmic Reticulum (sER) No surface ribosomes Function Synthesis of lipids, steroids, and carbohydrates. Metabolism of exogenous substances, such as drugs or toxins.  Functions of cellular structures – Golgi ILO: 1 body Structure Golgi body is a series of flattened membrane-bound sacs with its inner face near the rER. Proteins made in the rER are delivered to the inner face of the Golgi complex by transport vesicles. Golgi Body, human epithelial cell Function Ethan Perlstein, Daniel Korostyshevsky (2012) The proteins are processed and packaged into CIL:40420 secretory vesicles to be released from the Golgi complex. Processed proteins move into the cytosol, either for use by the cell or more commonly for delivery to the Golgi vesicles, yeast plasma membrane for export. cell David J. Gill, Joanne Chia, Jamie Senewiratne, Frederic Bard (2011) CIL:13570 Transport of vesicles from the Golgi ILO: 1 body Golgi body and vesicles, Brown Rat cell Mardones, Gonzalo A. (2010) CIL:8060  ILO: 1 Functions of cellular structures – Mitochondria Structure Dynamic organelles that can change shape, undergo fission and fusion, and move about within the cell. Contain their own genome consisting of circular mtDNA. Function The generation of energy as adenosine triphosphate (ATP) through oxidative phosphorylation. Involved in programmed cell death (apoptosis), Numerous mitochondria in human epithelial signalling, cell differentiation, and cell growth. Seok cell Min Jin, Michael Lazarou, Chunxin Wang, Lesley A. Kane, Derek P. Narendra, Richard J. Youle (2011) CIL:13722  ILO: 1 Functions of cellular structures – Lysosomes Lysosomes Membrane-bound vesicles that contain enzymes (acid hydrolases). Function Digestion of most chemical compounds (nucleic acids, carbohydrates, proteins, or lipids) endogenous to the cell or extracellular substances taken up by endocytosis or phagocytosis. Neutrophil lysosomes (Human) Don W. Fawcett (2011) CIL:10851  ILO: 1 The nucleus  ILO: 1 Functions of cellular structures – Nucleus & nucleolus Nucleus and nucleolus, Pancreatic acinar cell (Human) Don W. Fawcett (2011) CIL:10974  ILO: 1 DNA molecules – 200 trillion metres of information The DNA in chromosomes is condensed. The DNA is wrapped around histone proteins to form nucleosomes. Nucleosomes pack to form a condensed chromatin fibre. Chromatin condensing around histone proteins Jan Bednar et. al. (2012) CIL:39731, Gallus gallus gallus, erythrocyte. CIL. Dataset. https://doi.org/doi:10.7295/W9CIL39731  ILO: 2 What process is going on here?  ILO: 2 Cell division Embryonic cell, Sea Urchin George Von Dassow (2011) CIL:15806  ILO: 2 Cell division Cells divide and multiply during an organism's growth, in response to injury and with increased demand. Cells can only divide when they have accurately duplicated their genetic information (DNA). The genetic material must then be equally distributed between the two daughter cells.  ILO: 2 The cell cycle - A series of coordinated events Regulation Cell cycle tightly regulated. Cyclin dependant kinases (CDK’s) control cell growth and division Dysregulation of growth > uncontrolled proliferation and cancer