Cells: The Fundamental Units of Life PDF

Chapter 1 Cells: The Fundamental Units of Life 01-19 (F) – 01-22 (M) Learning Outcome To be able to state or describe the 3 theories relevant to the understanding of the fundamental principles of the cell The Cell Theory Cells are the fundamental and functional units of life. A cell is the structura...

Chapter 1 Cells: The Fundamental Units of Life 01-19 (F) – 01-22 (M) Learning Outcome To be able to state or describe the 3 theories relevant to the understanding of the fundamental principles of the cell The Cell Theory Cells are the fundamental and functional units of life. A cell is the structural unit of life. All organisms are made of cells. All cells arise from preexisting cells. helps explain commonality found in cells The Theory of Evolution (by Natural Selection) Optional video:https://www.youtube.com/watch?v=BcpB_986wyk Theory of Evolution random variation and natural selection can drive the production of organisms with novel features explains how diversity has arisen from organisms that share a common ancestry helps explain diversity found in cells Endosymbiont (Endosymbiotic) Theory proposes that certain organelles, notably mitochondria and chloroplasts, originated as bacterial symbionts within a nucleus-containing host cell helps explain how complex cells evolved Endosymbiont (Endosymbiotic) Theory https://www.youtube.com/watch?v=9i7kAt 97XYU&t=53s How we think complex cells evolved - Adam Jacobson, TEDEd watch Watch the Video Objectives: To address the following: oWhich theory explains how complex cells evolved? oWhat are the evidences that support this theory? 3 theories relevant to the understanding of the fundamental principles of the cell Theory of Evolution Cell Theory Endosymbiont (Endosymbiotic) Theory Learning Outcomes define a cell explain commonality and diversity of cells differentiate a prokaryotic cell from a eukaryotic cell identify some model organisms and their applications Cells basic unit of life; basic structure and functional unit of living organisms small, membrane-enclosed units filled with a concentrated aqueous solution of chemicals and endowed with the extraordinary ability to create copies of themselves by growing and dividing into two UNITY AND DIVERSITY OF CELLS Genes provide instructions for the form, function, and behavior of cells and organisms. Replicated transcribed translated transcription translation LIFE IS AN AUTOCATALYTIC PROCESS. RNA beginning all Of it These feedback loops create the selfreplicating system that endows living cells with their ability to reproduce. Essential Cell Biology, Fifth Edition Copyright © 2019 W. W. Norton & Company DISCOVERY OF CELLS The discovery of cells and their structure is linked to the development of the magnifying lenses, particularly the microscope. 1665 Robert Hooke – Reported to the Royal Society of London his observation of "Cells" in a piece of cork. NEW CELLS FORM BY GROWTH AND DIVISION OF EXISTING CELLS. (A) In 1880, Eduard Strasburger drew a living plant cell (a hair cell from a Tradescantia flower), which he observed dividing in two over a period of 2.5 hours. Inside the cell, DNA (black) can be seen condensing into chromosomes, which are then segregated into the two daughter cells. (B) A comparable living plant cell photographed through a modern light microscope. (B, from P.K. Hepler, J. Cell Biol. 100:1363–1368, 1985. With permission from Essential Cell Biology, Fifth Edition Rockefeller University Press.) Copyright © 2019 W. W. Norton & Company LEARNING OUTCOMES compare light microscopy and electron microscopy identify different types of microscopes and their respective uses. Reading Assignment: relevant resource: read pages 12-13: Panel 1-1 microscopy Why has it been difficult to study cells? What techniques were used to aid in studying cells? (1) very small (2) colorless transparent  Microscopes reveal some of a cell’s components. What techniques came and are being used to solve the problem of transparency? Staining techniques Using differences in refractive index among organelles optical techniques The use of fluorescent dyes. Highest level Tertiary is structure a a single polypeptide single polypeptide Chain structure quartenery bonded together a peptide chain chain can reach ? Cells form tissues in plants and animals.  Staining or Use of Dyes Essential Cell Biology, Fifth Edition Copyright © 2019 W. W. Norton & Company SOME OF THE INTERNAL STRUCTURES OF A CELL CAN BE SEEN WITH A LIGHT MICROSCOPE. (A) Light Microscope Interference-Contrast Optics (B) Confocal Microscopy Essential Cell Biology, Fifth Edition Copyright © 2019 W. W. Norton & Company  using differences in refractive index among organelles design that antibodies will attach to it  multiple fluorescent probes can be used in a single cell limitation  Light microscope can resolve only up to 0.2 micrometer –anything smaller can not be resolved of light electron microscope Limitation of light Super-resolution fluorescence microscopy can resolve up to 200 nm (0.2 μM) limitation Of light Essential Cell Biology, Fifth Edition Copyright © 2019 W. W. Norton & Company Two-color (d)STORM super-resolution image of nuclear pores in a HeLa cell. Nuclear pore complex protein Nup133 (green) was detected with CF®583R-conjugated secondary antibodies (DOL = 4.18), and Nup62 (magenta). (d)STORM was performed in an oxygen scavenging imaging buffer containing 50 mM MEA. Courtesy of Dr. Leonid Andronov, Moerner Laboratory, Stanford University. CELLS UNDER THE MICROSCOPE The Fine Structure of a Cell Is Revealed by Electron Microscopy can resolve details as small as about 3 nm-20 nm (scanning electron microscope) or about 1 nm (transmission electron microscope) THE FINE STRUCTURE OF A CELL CAN BE SEEN IN A TRANSMISSION ELECTRON MICROSCOPE. Essential Cell Biology, Fifth Edition Copyright © 2019 W. W. Norton & Company TRANSMISSION ELECTRON MICROSCOPY IMAGE Sion transmis electron & , mi croscope individual Fina organelles (peroxisomes 0.1– 1 µm diameter) (lysosomes 0.05– 0.5 µm diameter) Essential Cell Biology, Fifth Edition Copyright © 2019 W. W. Norton & Company Larger molecules can be seen under an electron microscope. Portion of a long, threadlike DNA molecule isolated from a cell and viewed by electron microscopy. Essential Cell Biology, Fifth Edition Copyright © 2019 W. W. Norton & Company SCANNING ELECTRON MICROSCOPE IMAGE details find on the Of surface the cell finer details Trichomes: A. thaliana LEARNING OUTCOMES compare light microscopy and electron microscopy identify different types of microscopes and their respective uses. Reading Assignment: relevant resource: read pages 12-13: Panel 1-1 microscopy Panel 1–1 Microscopy: reading assignment pages 12-13 Essential Cell Biology, Fifth Edition Copyright © 2019 W. W. Norton & Company CELL UNDER THE MICROSCOPE The Invention of the Light Microscope Led to the Discovery of Cells Cells, Organelles, and Even Molecules Can Be Seen Under the Microscope THE PROKARYOTIC CELL Prokaryotes Are the Most Diverse and Numerous Cells on Earth The World of Prokaryotes Is Divided into Two Domains: Bacteria and Archaea Bacteria come in different shapes and sizes. Essential Cell Biology, Fifth Edition Copyright © 2019 W. W. Norton & Company vokaryotic I Note: in a prokaryotic cell o absence of internal membrane bound compartments o absence of organelles no nucleus Essential Cell Biology, Fifth Edition Copyright © 2019 W. W. Norton & Company LEARNING OUTCOMES To be able to define cell’s components i.e. organelles and identify their functions To understand and explain why eukaryotic cells are thought to have evolved from prokaryotic cells 1 2 False.. False. True 3 IN THE EUCARYOTIC CELL The nucleus is the information store of the cell. The nucleus contains most of the DNA in a eukaryotic cell. Essential Cell Biology, Fifth Edition Copyright © 2019 W. W. Norton & Company the most prominent organelle Nucleuse Chromosomes become visible when a cell is nucleus about to divide. Found in Essential Cell Biology, Fifth Edition Copyright © 2019 W. W. Norton & Company Low-power scanning electron Field-emission scanning microscopy (SEM) of whole oocyte electron microscopy (FESEM) nuclear envelope imaging of the oocyte nuclear envelope. THE EUKARYOTIC CELL Mitochondria Generate Usable Energy from Food Molecules present essentially in all eukaryotic cells This budding yeast cell, which contains a green fluorescent protein in its mitochondria, was viewed in a superthe mitochondria are seen to form resolution confocal fluorescence complex branched networks microscope. In this three-dimensional image, the mitochondria are seen to form complex branched networks. Essential Cell Biology, Fifth Edition Copyright © 2019 W. W. Norton & Company MITOCHONDRIA CAN VARY IN SHAPE AND SIZE. typically described to be sausage shaped, worm-like or disc shaped https://www.youtube.com/watch?v=WU4UU2Gmy5w MITOCHONDRIA HAVE A DISTINCTIVE INTERNAL STRUCTURE. de nSI I mitochondria electron transport chain Essential Cell Biology, Fifth Edition Copyright © 2019 W. W. Norton & Company Organelle that energy for generates Eukaryotes Essential Cell Biology, Fifth Edition Copyright © 2019 W. W. Norton & Company MITOCHONDRIA ARE THOUGHT TO HAVE EVOLVED FROM ENGULFED BACTERIA. resemble bacteria and thought to be derived from bacteria engulfed by the ancestor of present day eukaryotes What gives people power ? mitochondria ↳ ATP Essential Cell Biology, Fifth Edition Copyright © 2019 W. W. Norton & Company ONE PROTOZOAN EATS ANOTHER. Essential Cell Biology, Fifth Edition Copyright © 2019 W. W. Norton & Company Didanium ingesting a Paramecium Chloroplast > 2 membrane Sustem mitochondria-3 membrane THE EUKARYOTIC CELL system Chloroplasts Capture Energy from Sunlight is the as same nucleus and typical in plants and algae mitochonaria thylakoid membranes Essential Cell Biology, Fifth Edition Copyright © 2019 W. W. Norton & Company CHLOROPLASTS ALMOST CERTAINLY EVOLVED FROM ENGULFED PHOTOSYNTHETIC BACTERIA. Essential Cell Biology, Fifth Edition Copyright © 2019 W. W. Norton & Company THE EUKARYOTIC CELL Internal membranes create intracellular compartments with different functions. Membrane Functions: Protective Physical Barrier Selective Chemical Barrier Encapsulates Specialized Compartments Compartilization - Organelle allows to THE ENDOPLASMIC RETICULUM PRODUCES MANY OF THE COMPONENTS OF A EUKARYOTIC CELL. Cell types that are more enriched With ER Essential Cell Biology, Fifth Edition Copyright © 2019 W. W. Norton & Company THE GOLGI APPARATUS IS COMPOSED OF A STACK OF FLATTENED, MEMBRANE-ENCLOSED DISCS. Essential Cell Biology, Fifth Edition Copyright © 2019 W. W. Norton & Company INTERNAL MEMBRANE STRUCTURES ER- site of synthesis of cell membrane components and proteins for export; protein modification Golgi – further modification in particular glycosylation Peroxisome- detoxification and in the process H2O2 is produced Lysosome-intracellular digestion Importance of lysosomal enzymes emphasized … Gaucher's disease, one of the 45 known lysosomal storage disorders absence of glucocerebrosidase accumulations of non-degraded products interferes with normal cell metabolism, and eventually in tissue function present as nervous disorders malfunction in organelles diseases can cause VESICLES EUKARYOTIC CELLS ENGAGE IN CONTINUAL ENDOCYTOSIS AND EXOCYTOSIS ACROSS THEIR PLASMA MEMBRANE. going in of molecules from going outside to inside out Essential Cell Biology, Fifth Edition Copyright © 2019 W. W. Norton & Company Terminology: Cytoplasm versus Cytosol Membrane-enclosed organelles are distributed throughout the eukaryotic cell cytoplasm. CUOSO get like Solution all organelles The cytoplasm that fills the space outside of these organelles is called the cytosol (colored blue). THE EUKARYOTIC CELL The cytosol is a concentrated aqueous gel of large and small molecules. In eukaryotic cells, the cytoplasm includes all of the material inside the cell and outside of the nucleus. Cytoplasm is not simply a structure less soup of chemicals and organelles. CYTOPLASM IS NOT SIMPLY A STRUCTURE LESS SOUP OF CHEMICALS AND ORGANELLES. There are structures that give the cell its shape and help organize the cell's parts. Cytoskeleton Supports the Structure THE CYTOSKELETON IS A NETWORK OF PROTEIN FILAMENTS THAT CAN BE SEEN CRISS-CROSSING THE CYTOPLASM OF EUKARYOTIC CELLS. actin microtubules intermediate The three major types of filaments can be detected using different fluorescent stains. Shown here are (A) actin filaments, (B) microtubules, and (C) intermediate filaments. Essential Cell Biology, Fifth Edition Copyright © 2019 W. W. Norton & Company Long fine filaments of protein; the thinnest Actin- in all eukaryotic cells, large numbers in muscle cells- contraction; cell support and cell movement involved in abundant in muscle cell our muscle contraction Microtubules- thickest filament; organelle and chromosome movement anization Org and movement Structure that microtubuleesred allows in element chromosom Essential Cell Biology, Fifth Edition Copyright © 2019 W. W. Norton & Company Intermediate filaments –strengthen the cell mechanically noted to provide mechanical Strenght and organization for Figure 1-26 Essential Cell Biology (© Garland Science 2014) THE EUKARYOTIC CELL The Nucleus Is the Information Store of the Cell Mitochondria Generate Usable Energy from Food Molecules Chloroplasts Capture Energy from Sunlight Internal Membranes Create Intracellular Compartments with Different Functions THE EUKARYOTIC CELL The Cytosol Is a Concentrated Aqueous Gel of Large and Small Molecules The Cytoskeleton Is Responsible for Directed Cell Movements The Cytosol Is Far from Static Eukaryotic Cells May Have Originated as Predators THE EUKARYOTIC CELL The cytoskeleton of a cell is made up of microtubules, actin filaments, and intermediate filaments. They are protein filaments. The cytoskeleton give the cell its shape and help organize the cell's parts. In addition, they provide a basis for movement and cell division. THE EUKARYOTIC CELL The cytoskeleton is responsible for directed cell movements The cytoplasm is far from static