Introduction to Cell Biology PDF

INTRODUCTION TO CELL BIOLOGY Mike Philpott Reading: Mol Biol of the Cell (Alberts et al) chapter 1 4th edition is available on line at https://www.ncbi.nlm.nih.gov/books/NBK26864/ accessible by the search feature LEARNING OUTCOMES for this week Thi...

INTRODUCTION TO CELL BIOLOGY Mike Philpott Reading: Mol Biol of the Cell (Alberts et al) chapter 1 4th edition is available on line at https://www.ncbi.nlm.nih.gov/books/NBK26864/ accessible by the search feature LEARNING OUTCOMES for this week This week we will discuss The cell as the smallest living entity What is meant by a living entity The history of cell discovery Cell Theory The importance of microscopy in cell biology Why Study Cell Biology ? 載入中⋯ Why is Cell Biology Important to Medicine?  What are cells? Either ea or pro Small units bound by a plasma membrane Contain aqueous fluid cytoplasm Genetic material nucleoid/nucleus Ability to synthesise proteins ribosomes Membrane bound organelles-eukaryotes* Cell wall plants and bacteria *we will discuss differences between eukaryotic and prokaryotic organisms next week  Cell Theory Unifying Foundation of Cell Biology All organisms are composed or one or more cells 載入中⋯ Cells are the smallest living entity Cells arise only by division of a previously existing 的 cell Howwas thefirst callfomd ? Thefirstaell by the enclosure of selforeplicaing RNA is thought to huve ariben andassuiaed molemes in menbreω uposedof phosphotipids 。 一  Cell Theory Every thing that is alive on our planet is either a cell or is made up of a collection of cells. The cell is the simplest thing can that be definitively said to be alive 一  All organisms are composed of one or more cells Cells Tissues Organs Organ systems (endocrine, reproductive, cardiovascular, renal, etc.) Organism! i.e., YOU  What do we mean by “living”? All living entities have to: harness energy respire grow & develop reproduce respond to stimuli  Important to remember? Smallest living entity Not smallest thing of relevance to biochemistry, biology, medicine or dentistry Not smallest infectious agent! 一  Viruses and Prions Prio n Viruses Can they be defined as living entities ?  viruses rions Viroids - infechous Barile1infechous protlins infectionRuAmolecales □ WA surromdedby justProteinrtself - stvndofRNA single Proteinenveloppe) ( no DAorRNA ) ( roprotein ) clagpsids -infects all orgnisms caube rlurodegeura在 d iHect plutsmostly cliseases resistuttopro 比ases ho Can withstrdextreane onditiors Doitrespond t. imuli Doit usetheirenegy Viruses : Doit veprooluu theirown n Conly veplicate via hostulls ) 項皆不們 ( (5 Doitgrow only live inhostull lo ytoplasm / allular organelles Mometabolismon their own 大 一 一 Do these properties apply to plants? All living entities have to: harness energy respire 載入中⋯ reproduce grow & develop respond to stimuli Do these properties apply to cells? All living entities have to harness energy Take in energy -eat and drink Use that energy to perform work See lecture by Dr Ros Hannen We have to eat and drink to survive. So do cells Endocytosis describes transport into cells phagocytosis = “cell eating” pinocytosis = “cell drinking” Phagocytosis Do these properties apply to cells? All living entities have to: respire Respiration is a chemical reaction by which energy is released from food Aerobic respiration presence of oxygen Anaerobic respiration absence of oxygen  Do these properties apply to cells? All living entities have to: reproduce (biogenesis) Cell Division/Proliferation mitosis (somatic / non-germ cells) meiosis (germ cells e.g. sperm and oocyte) All life come from pre-existing life Cell cycle and Cell Division. Dr Caley 一 Do these properties apply to cells? All living entities have to: grow and develop I cell fertilised oocyte gives rise to 37 trillion cell embryo Cell cycle and Cell Division. Dr Caley & Stem Cells and Differentiation. Dr Biddle All living entities have to: grow and develop cell’s differentiate / specialise Recent estimate of 37 Trillion cells in the human body Approximately 210 Different cell types Make up the tissues and organs of the body Stem Cells and Differentiation. Dr Biddle  Cell-Tissue-Organ Differentiated cells that specify tissue and organ function  Hyperplasia 的 Cell 的九 不變 Abnormal increase in size of organ due to increased cell division in response to a stimuli ∅ normalulls Benign prostatic hyperplasia Psoriasis b abnomalcalls Hyperplasia Cancer. Dr Bergamaschi 。 小  Hypertrophy cell’s can get larger (hypertrophy) e.g. Muscle cells with exercise Hypertrophy can be associated with disease : hard for the heartto pumpblood  All living entities: respond to stimuli Cell Membranes and Transmembrane Transport. Prof Linton Transmembrane Signalling. Dr Maffucci  cells divide in response to mitogens imula all dvisions 在 move in response to morphogens d Cuuleadll 去se. , or orgnism ) to evelop its shape 心 History of cell discovery The importance of and the cell theory microscopy in cell biology History of cell Discovery  The history of cell biology 1665 – Robert Hooke: English philosopher, architect & polymath In Sept.1665 (aged 30), Hooke published:  The history of cell biology 1665 – Robert Hooke: Coined the term “cells” to describe “tiny boxes” (honeycomb) in cork Thought only existed in plants & fungi Never got full credit due to falling out with Isaac Newton  The history of cell biology 1673 – Anton van Leeuwenhoek: Dutch tradesman & scientist Pioneer in microscopy Invented 25 different hand-made microscopes  The history of cell biology 1673 – Anton van Leeuwenhoek: Observed unicellular microorganisms 載入中⋯ (“animalcules”) in pond water  Anton van Leeuwenhoek Observed blood cells in vertebrates 背椎動物 。  The history of cell biology Anton van Leeuwenhoek 1674 – protozoans (Protista) 1676 – bacteria 1677 – vacuole 1677 – spermatozoan 1682 – striated muscle fibres c.560 letters to the Royal Society At the time other scientists including Hooke could not work out how Leeuwenhoek could magnify such small objects 350 years to work out secret of Leeuwenhoek’s success Expertly ground lenses Neutron tomography of Van Leeuwenhoek’s microscopes DOI: 10.1126/sciadv.abf2402  The18th history of Century the age of cell biology enlightenment Often described as a drab century for science advances important time for Chemistry and astronomy And start of popular science  The history of cell biology 1838 – Matthias Schleiden: German botanist 植物學家 Concluded all plant parts are made of cells  The history of cell biology 1839 – Theodor Schwann German physiologist Stated that all animal tissues are made of cells  The history of cell biology 1858 – Rudolf Virchow German physician Didn’t accept the popular theory of spontaneous generation 的在無相物中 然產 Concluded cells arise from pre- existing cells 。 自 生  The history of cell biology The Cell Theory 19th Century - Cell theory postulate: All organisms consist of one or more cells (Schleiden & Schwann) The cell is the basic structural unit of all organisms (Schleiden & Schwann) All cells arise from pre-existing cells – “omnis cellulae cellula” (Virchow)  The history of cell biology Cell theory postulate not only holds the cell to be the①smallest living entity (the fundamental unit of life), but to be the ② basis for reproduction!  The history of cell 1950 –biology Watson & Crick ( 可遺傳物質) = DWA The cell contains the hereditary information (DNA) which is passed from cell to cell during cell division Modern cell biology at cross-roads of cytology biochemistry genetics 。  Microscopy Microscopy was pivotal in the development of the cell theory Pioneering studies used light microscopes https://www.jic.ac.uk/microscopy/scale.html Where do cells sit on the spectrum of life? Atom Max resolution – small moleanles 0.2 nm (2 x 10-10 m) electron microscope 2 nm (2 x 10-9 m) Molecule 20 nm (2 x 10-8 m) Max resolution – 200 nm (2 x 10-7 m) light microscope Organelle 2 µm (2 x 10-6 m) Cells 20 µm (2 x 10-5 m) 200 µm (2 x 10-4 m) Max resolution – unaided eye  Scale This image has been taken from Molecular Biology of the Cell, fourth edition, courtesy of Garland science publishing  Light microscopy: Subtypes of light microscopy: Brightfiel光學夏微鏡 Phase Cuse ) d lighe contrast Differential Fluorescen phase ce only thimscmple contrast - , 3D - image ) Confoc al - Generute D imageof livsng calls. exausMe changes occursin cells owertime True ? exauihethickscample 月  Fluorescence microscopy is probably the most readily oReason ? Uses antibodies toused technique detect a specific protein and a fluorescent probe to detect the binding antibody Immunocytochemist Immunohistochemist ry ry Cells Tissues  Confocal Microscope The confocal microscope is a fluorescent microscope that allows 3D images to be obtained Mumps virus in ER of infected cell  Live cell Imaging Time lapse imaging 縮時攝影 Allows greater understanding of how cells move and function in real time But also intracellular trafficking 0 theactive trusport of pwteins , resicles , organelles bymolecular Motors along micwtabuleland actin 微管 肌動蛋仔 。 Live cell Imaging  Super high resolution microscopy Allows resolution below 100nM - 9 loo × 1 o metve = 10 Ametres https://youtu.be/W-0GWbOFT3w 。 Super high resolution microscopy Makes imaging at theranoscales moreaccessible https://youtu.be/W-0GWbOFT3w  The history of cell biology Subtypes of electron microscopy:→ onty dead organisms Scanning EM small Transmission EM small intestine intestine - magrif乎 y I - 2 mit[ or times - Magrify by Mone than 50 millior times larger Maximum fiesdofvrew: lager only exanme small ofthescmple - - excamine part scample LEARNING OUTCOMES By the time that you have completed this week, you should be able to: Explain what cells are Define what is meant by the term ‘living entity’ Outline the history of cell discovery and the importance of microscopy Antibodies for all cell organelles Next week we will discuss cell organelles and variations on a theme