Microbiology with Diseases By Taxonomy (PDF)

Microbiology with Diseases by Taxonomy Sixth Edition Chapter 3 Cell Structure and Function PowerPoint® Lecture...

Microbiology with Diseases by Taxonomy Sixth Edition Chapter 3 Cell Structure and Function PowerPoint® Lecture Presentations prepared by Mindy Miller-Kittrell, North Carolina State University Copyright © 2020, 2017, 2014 Pearson Education, Inc. All Rights Reserved Processes of Life (1 of 2) Growth Reproduction Responsiveness Metabolism Copyright © 2020, 2017, 2014 Pearson Education, Inc. All Rights Reserved Table 3.1 Characteristics of Life and Their Distribution in Microbes Characteristic Bacteria, Archaea, Viruses Eukaryotes Growth: increase in size Occurs in all Growth does not occur Reproduction: increase in Occurs in all Host cell replicates the virus number Responsiveness: ability to react Occurs in all Reaction to host cells seen in to environmental stimuli some viruses Metabolism: controlled chemical Occurs in all Viruses use host cell’s reactions of organisms metabolism Cellular structure: membrane- Present in all Viruses lack cytoplasmic bound structure capable of all of membrane or cellular structure the above functions Copyright © 2020, 2017, 2014 Pearson Education, Inc. All Rights Reserved  Prokaryotic Cells: An Overview (1 of 3) Prokaryotes – Lack nucleus ▪ Can read DNA and make protein simultaneously – Lack various internal structures bound with phospholipid membranes – Are typically 1.0m in diameter or smaller – Includes bacteria and archaea Copyright © 2020, 2017, 2014 Pearson Education, Inc. All Rights Reserved  Eukaryotic Cells: An Overview (2 of 3) Eukaryotes – Have nucleus – Have internal membrane-bound organelles – Are larger: 10–100 µmein diameter – Have more complex structure – Composed of algae, protozoa, fungi, animals, and plants Copyright © 2020, 2017, 2014 Pearson Education, Inc. All Rights Reserved Figure 3.4 Approximate Size of Various Types of Cells Copyright © 2020, 2017, 2014 Pearson Education, Inc. All Rights Reserved External Structures of Bacterial Cells (1 of 7) Glycocalyces – Gelatinous, sticky substance surrounding the outside of the cell – Composed of polysaccharides, polypeptides, or both Two Types of Glycocalyces – Capsule ▪ Composed of organized repeating units of organic chemicals ▪ Firmly attached to cell surface ▪ May prevent bacteria from being recognized by host – Slime layer ▪ Loosely attached to cell surface ▪ Water-soluble ▪ Sticky layer allows prokaryotes to attach to surfaces. Copyright © 2020, 2017, 2014 Pearson Education, Inc. All Rights Reserved Figure 3.5 Glycocalyces Copyright © 2020, 2017, 2014 Pearson Education, Inc. All Rights Reserved Motility Copyright © 2020, 2017, 2014 Pearson Education, Inc. All Rights Reserved  External Structures of Bacterial Cells (3 of 7) Flagella – Are responsible for movement Figure 3.6 Proximal Structure of Bacterial Flagella – Have long structures that extend beyond cell surface – Are not present on all bacteria – Structure ▪ Composed of filament, hook, and basal body – Basal body anchors the filament and hook to cell wall. Copyright © 2020, 2017, 2014 Pearson Education, Inc. All Rights Reserved Flagella: Structure Copyright © 2020, 2017, 2014 Pearson Education, Inc. All Rights Reserved Figure 3.7 Micrographs of Basic Arrangements of Bacterial Flagella Copyright © 2020, 2017, 2014 Pearson Education, Inc. All Rights Reserved Flagella: Arrangement Copyright © 2020, 2017, 2014 Pearson Education, Inc. All Rights Reserved Figure 3.8 Axial Filament Copyright © 2020, 2017, 2014 Pearson Education, Inc. All Rights Reserved Spirochetes Copyright © 2020, 2017, 2014 Pearson Education, Inc. All Rights Reserved External Structures of Bacterial Cells (5 of 7) Flagella – Function ▪ Rotation propels bacterium through environment. ▪ Rotation is reversible; can be counterclockwise or clockwise ▪ Bacteria move in response to stimuli (taxis). – Runs Figure 3.9 Motion of a Peritrichous Bacterium – Tumbles Copyright © 2020, 2017, 2014 Pearson Education, Inc. All Rights Reserved Flagella: Movement Copyright © 2020, 2017, 2014 Pearson Education, Inc. All Rights Reserved  External Structures of Bacterial Cells (6 of 7) Fimbriae and Pili – Fimbriae ▪ Sticky, bristlelike projections ▪ Used by bacteria to adhere to one another and to substances in environment ▪ Shorter than flagella ▪ Serve an important function in biofilms Copyright © 2020, 2017, 2014 Pearson Education, Inc. All Rights Reserved  External Structures of Bacterial Cells Fimbriae and Pili – Pili ▪ Special type of fimbriae ▪ Also known as conjugation pili ▪ Longer than fimbriae but shorter than flagella ▪ Bacteria typically have only one or two per cell. ▪ Transfer DNA from one cell to another (conjugation) Copyright © 2020, 2017, 2014 Pearson Education, Inc. All Rights Reserved  Bacterial Cell Walls (1 of 4) Provide structure and shape and protect cell from osmotic forces Assist some cells in attaching to other cells or in resisting antimicrobial drugs Can target cell wall of bacteria with antibiotics Give bacterial cells characteristic shapes Figure 3.13 Bacterial Shapes and Arrangements Copyright © 2020, 2017, 2014 Pearson Education, Inc. All Rights Reserved Bacterial Cell Walls (2 of 4) Composed of peptidoglycan Scientists describe two basic types of bacterial cell walls: – Gram-positive and Gram-negative Figure 3.15 Possible Structure of Peptidoglycan Copyright © 2020, 2017, 2014 Pearson Education, Inc. All Rights Reserved  Bacterial Cell Walls (3 of 4) Gram-Positive Bacterial Cell Walls – Relatively thick layer of peptidoglycan – Contain unique chemicals called teichoic acids and lipoteichoic acids – Appear purple following Gram staining procedure – Up to 60% mycolic acid in acid-fast bacteria helps cells survive desiccation Copyright © 2020, 2017, 2014 Pearson Education, Inc. All Rights Reserved  Bacterial Cell Walls (1 of 2) Gram-Negative Bacterial Cell Walls – Have only a thin layer of peptidoglycan – Bilayer membrane outside the peptidoglycan contains phospholipids, proteins, and lipopolysaccharide (LPS) ▪ Lipid A portion of LPS can cause fever, vasodilation, inflammation, shock, and blood clotting. – May impede the treatment of disease. – Appear pink following Gram staining procedure Copyright © 2020, 2017, 2014 Pearson Education, Inc. All Rights Reserved Bacterial Cell Walls (2 of 2) Bacteria Without Cell Walls – A few bacteria lack cell walls – Often mistaken for viruses due to small size and lack of cell wall – Have other features of prokaryotic cells such as ribosomes Copyright © 2020, 2017, 2014 Pearson Education, Inc. All Rights Reserved  Bacterial Cytoplasmic Membranes (1 of 4) Structure – Referred to as phospholipid bilayer ▪ Composed of lipids and associated proteins: – Integral proteins – Peripheral proteins – Fluid mosaic model describes current understanding of membrane structure Figure 3.17 Structure of a Prokaryotic Cytoplasmic Membrane: A Phospholipid Bilayer Copyright © 2020, 2017, 2014 Pearson Education, Inc. All Rights Reserved Membrane Structure Copyright © 2020, 2017, 2014 Pearson Education, Inc. All Rights Reserved  Bacterial Cytoplasmic Membranes (2 of 4) Function – Controls passage of substances into and out of the cell – Harvest light energy in photosynthetic bacteria – Selectively permeable – Naturally impermeable to most substances – Proteins allow substances to cross membrane – Maintain concentration and electrical gradient Copyright © 2020, 2017, 2014 Pearson Education, Inc. All Rights Reserved Membrane Permeability Copyright © 2020, 2017, 2014 Pearson Education, Inc. All Rights Reserved Figure 3.18 Electrical Potential of a Cytoplasmic Membrane Copyright © 2020, 2017, 2014 Pearson Education, Inc. All Rights Reserved Passive Transport: Principles of Diffusion Copyright © 2020, 2017, 2014 Pearson Education, Inc. All Rights Reserved Bacterial Cytoplasmic Membranes (3 of 4) Function – Passive processes ▪ Diffusion ▪ Facilitated diffusion ▪ Osmosis Figure 3.19 Passive Processes of Movement Across a Cytoplasmic Membrane Copyright © 2020, 2017, 2014 Pearson Education, Inc. All Rights Reserved Figure 3.20 Osmosis, the Diffusion of Water Across a Semipermeable Membrane Copyright © 2020, 2017, 2014 Pearson Education, Inc. All Rights Reserved Figure 3.21 Effects of Isotonic, Hypertonic, and Hypotonic Solutions on Cells Copyright © 2020, 2017, 2014 Pearson Education, Inc. All Rights Reserved Passive Transport: Special Types of Diffusion Copyright © 2020, 2017, 2014 Pearson Education, Inc. All Rights Reserved  Bacterial Cytoplasmic Membranes Function – Active processes ▪ Active transport ▪ Group translocation – Substance is chemically modified during transport. Figure 3.23 Group Translocation Figure 3.22 Mechanisms of Active Transport Copyright © 2020, 2017, 2014 Pearson Education, Inc. All Rights Reserved Active Transport: Overview Copyright © 2020, 2017, 2014 Pearson Education, Inc. All Rights Reserved Active Transport: Types Copyright © 2020, 2017, 2014 Pearson Education, Inc. All Rights Reserved Table 3.2 Transport Processes Across Bacterial Cytoplasmic Membranes Blank Description Examples of Transported Substances Passive Transport Processes require no use of energy by the cell; Blank Processes the electrochemical gradient provides energy. Diffusion Molecules move down their electrochemical Oxygen, carbon dioxide, gradient through the phospholipid bilayer of the lipid-soluble chemicals membrane. Facilitated diffusion Molecules move down their electrochemical Glucose, fructose, urea, gradient through channels or carrier proteins. some vitamins Osmosis Water molecules move down their concentration Water gradient across a selectively permeable membrane. Active Transport Cell expends energy in the form of ATP to move Blank Processes a substance against its electrochemical gradient. Active transport ATP-dependent carrier proteins bring Na+, K+, Ca2+, H+, Cl− substances into cell. Group translocation The substance is chemically altered during Glucose, mannose, transport. fructose Copyright © 2020, 2017, 2014 Pearson Education, Inc. All Rights Reserved  Cytoplasm of Bacteria Cytosol – Liquid portion of cytoplasm – Mostly water – Contains cell’s DNA in region called the nucleoid Inclusions – May include reserve deposits of chemicals Endospores – Unique structures produced by some bacteria – Defensive strategy against unfavorable conditions – Vegetative cells transform into endospores when multiple nutrients are limited – Resistant to extreme conditions such as heat, radiation, chemicals Figure 3.25a Formation of an Endospore Copyright © 2020, 2017, 2014 Pearson Education, Inc. All Rights Reserved Cytoplasm of Eukaryotes (1 of 3) Nonmembranous Organelles – Ribosomes ▪ Sites of protein synthesis ▪ Composed of polypeptides and ribosomal R N A ▪ Prokaryotic and eukaryotic ribosomes have structural differences – Prokaryotes have 70S ribosomes – Eukaryotes have 80S ribosomes Copyright © 2020, 2017, 2014 Pearson Education, Inc. All Rights Reserved Cytoplasm of Prokaryotes (2 of 3) Nonmembranous Organelles – Cytoskeleton ▪ Composed of three or four types of protein fibers ▪ Can play different roles in the cell: – Cell division – Cell shape – Segregate DN A molecules – Move through the environment Copyright © 2020, 2017, 2014 Pearson Education, Inc. All Rights Reserved External Structures of Archaea (1 of 2) Glycocalyces – Function in the formation of biofilms – Adhere cells to one another and inanimate objects Flagella – Consist of basal body, hook, and filament – Numerous differences with bacterial flagella Fimbriae and Hami – Many archaea have fimbriae. – Some make fimbria-like structures called hami. ▪ Function to attach archaea to surfaces Copyright © 2020, 2017, 2014 Pearson Education, Inc. All Rights Reserved Figure 3.27 Archaeal Hami Copyright © 2020, 2017, 2014 Pearson Education, Inc. All Rights Reserved Archaeal Cell Walls and Cytoplasmic Membranes (1 of 2) Most archaea have cell walls. – Do not have peptidoglycan – Contain variety of specialized polysaccharides and proteins All archaea have cytoplasmic membranes. – Maintain electrical and chemical gradients – Control import and export of substances from the cell Figure 3.28 Representative Shapes of Archaea Copyright © 2020, 2017, 2014 Pearson Education, Inc. All Rights Reserved Cytoplasm of Archaea (1 of 2) Archaeal cytoplasm similar to bacterial cytoplasm: – 70S ribosomes – Fibrous cytoskeleton – Circular DNA Archaeal cytoplasm also differs from bacterial cytoplasm: – Different ribosomal proteins – Different metabolic enzymes to make RNA – Genetic code more similar to eukaryotes Copyright © 2020, 2017, 2014 Pearson Education, Inc. All Rights Reserved Table 3.3 Some Structural Characteristics of Prokaryotes Feature Archaea Bacteria Glycocalyx Polypeptide or polysaccharide Polypeptide or polysaccharide Flagella Present in some; 10–14 n m in diameter; ano eter Present in some; about 20 n m in diameter; grow at ano eter grow at base; rotate both counterclockwise the tip; rotate counterclockwise in bundles to cause and clockwise as bundles runs; rotate independently clockwise to cause tumbles Fimbriae Proteinaceous; used for attachment and in Proteinaceous; used for attachment, gliding formation of biofilms motility, and in formation of biofilms Pili None discovered Present in some; proteinaceous; used in bacterial exchange of DNA Hami Present in some; used for attachment Absent Cell Walls Present in most; composed of Present in most; composed of peptidoglycan, a polysaccharides (not peptidoglycan) or polysaccharide proteins Cytoplasmic Present in all; membrane lipids are made Present in all; phospholipids are made with ester Membrane with ether linkages; linkages in bilayer some have single lipid layer Cytoplasm Cytosol contains circular DNA molecule and Cytosol contains a circular DNA molecule and 70S 70S ribosomes; ribosomal proteins are ribosomes with bacterial proteins similar to eukaryotic ribosomal proteins Copyright © 2020, 2017, 2014 Pearson Education, Inc. All Rights Reserved External Structure of Eukaryotic Cells (1 of 2) Glycocalyces – Not as organized as prokaryotic capsules – Help anchor animal cells to each other – Strengthen cell surface – Provide protection against dehydration – Function in cell-to-cell recognition and communication Copyright © 2020, 2017, 2014 Pearson Education, Inc. All Rights Reserved Eukaryotic Cell Walls and Cytoplasmic Membranes (1 of 3) Fungi, algae, plants, and some protozoa have cell walls. Composed of various polysaccharides: – Cellulose found in plant cell walls – Fungal cell walls composed of cellulose, chitin, and/or glucomannan – Algal cell walls composed of a variety of polysaccharides Copyright © 2020, 2017, 2014 Pearson Education, Inc. All Rights Reserved Eukaryotic Cell Walls and Cytoplasmic Membranes (2 of 3) All eukaryotic cells have cytoplasmic membranes. – Are a fluid mosaic of phospholipids and proteins – Contain steroid lipids to help maintain fluidity – Contain regions of lipids and proteins called membrane rafts – Control movement into and out of cell Copyright © 2020, 2017, 2014 Pearson Education, Inc. All Rights Reserved Table 3.4 Active Transport Processes Found Only in Eukaryotes: Endocytosis and Exocytosis Blank Description Examples of Transported Substances Endocytosis: Substances are surrounded by Bacteria, viruses, aged and dead Phagocytosis and pseudopods and brought into cells; liquid nutrients in extracellular Pinocytosis the cell. Phagocytosis involves solutions solid substances; pinocytosis involves liquids. Exocytosis Vesicles containing substances Wastes, secretions are fused with cytoplasmic membrane, dumping their contents to the outside. Copyright © 2020, 2017, 2014 Pearson Education, Inc. All Rights Reserved Eukaryotic Cell Walls and Cytoplasmic Membranes (3 of 3) Tell Me Why – Many antimicrobial drugs target bacterial cell walls. Why aren’t there many drugs that act against bacterial cytoplasmic membranes? Copyright © 2020, 2017, 2014 Pearson Education, Inc. All Rights Reserved Cytoplasm of Eukaryotes (1 of 14) Flagella – Structure and arrangement ▪ Differ structurally and functionally from prokaryotic flagella – Within the cytoplasmic membrane – Shaft composed of tubulin arranged to form microtubules. ▪ Filaments anchored to cell by basal body; no hook ▪ May be single or multiple; generally found at one pole Copyright © 2020, 2017, 2014 Pearson Education, Inc. All Rights Reserved Figure 3.32 Eukaryotic Flagella and Cilia Copyright © 2020, 2017, 2014 Pearson Education, Inc. All Rights Reserved Cytoplasm of Eukaryotes (2 of 14) Flagella – Function ▪ Eukaryotic flagella move differently from those of prokaryotes ▪ Undulate rhythmically ▪ Either push or pull a cell through the medium Figure 3.33a Movement of Eukaryotic Flagella and Cilia Copyright © 2020, 2017, 2014 Pearson Education, Inc. All Rights Reserved Cytoplasm of Eukaryotes (3 of 14) Cilia – Shorter and more numerous than flagella – Coordinated beating propels cells through their environment. – Also used to move substances past the surface of the cell Figure 3.33b Movement of Eukaryotic Flagella and Cilia Copyright © 2020, 2017, 2014 Pearson Education, Inc. All Rights Reserved  Cytoplasm of Eukaryotes (4 of 14) Other Nonmembranous Organelles – Ribosomes ▪ Larger than prokaryotic ribosomes (80S versus 70S) ▪ Composed of 60S and 40S subunits – Cytoskeleton ▪ Extensive network of fibers and tubules ▪ Anchors organelles ▪ Produces basic shape of the cell ▪ Made up of tubulin microtubules, actin microfilaments, and intermediate filaments Figure 3.34 Eukaryotic Cytoskeleton Copyright © 2020, 2017, 2014 Pearson Education, Inc. All Rights Reserved  Cytoplasm of Eukaryotes (5 of 14) Other Nonmembranous Organelles – Centrioles and centrosome ▪ Centrioles play a role in mitosis, cytokinesis, and formation of flagella and cilia. ▪ Centrosome is region of cytoplasm where centrioles are found. ▪ Not found in all eukaryotic cells Figure 3.35 Centrosome Copyright © 2020, 2017, 2014 Pearson Education, Inc. All Rights Reserved  Cytoplasm of Eukaryotes (6 of 14) Membranous Organelles – Nucleus ▪ Often largest organelle in cell ▪ Contains most of the cell’s DNA ▪ Semiliquid portion called nucleoplasm – Contains chromatin ▪ RNA synthesized in nucleoli present in nucleoplasm. ▪ Surrounded by nuclear envelope – Contains nuclear pores Copyright © 2020, 2017, 2014 Pearson Education, Inc. All Rights Reserved  Cytoplasm of Eukaryotes (7 of 14) Membranous Organelles – Endoplasmic reticulum (ER) ▪ Netlike arrangement of flattened, hollow tubules continuous with nuclear envelope ▪ Functions as transport system ▪ Two forms: – Smooth endoplasmic reticulum (SER) – Rough endoplasmic reticulum (RER) Copyright © 2020, 2017, 2014 Pearson Education, Inc. All Rights Reserved  Cytoplasm of Eukaryotes (8 of 14) Membranous Organelles – Golgi body ▪ Receives, processes, and packages large molecules for export from cell ▪ Packages molecules in secretory vesicles that fuse with cytoplasmic membrane ▪ Composed of flattened hollow sacs surrounded by phospholipid bilayer ▪ Not in all eukaryotic cells Copyright © 2020, 2017, 2014 Pearson Education, Inc. All Rights Reserved  Cytoplasm of Eukaryotes (9 of 14) Membranous Organelles – Lysosomes, peroxisomes, vacuoles, and vesicles ▪ Store and transfer chemicals within cells ▪ May store nutrients in cell ▪ Lysosomes contain catabolic enzymes. ▪ Peroxisomes contain enzymes that degrade poisonous wastes. Figure 3.39 Vacuole Copyright © 2020, 2017, 2014 Pearson Education, Inc. All Rights Reserved Figure 3.40 Roles of Vesicles in Endocytosis and Exocytosis Copyright © 2020, 2017, 2014 Pearson Education, Inc. All Rights Reserved  Cytoplasm of Eukaryotes (10 of 14) Membranous Organelles – Mitochondria ▪ Have two membranes composed of phospholipid bilayer ▪ Produce most of cell’s ATP ▪ Interior matrix contains 70S ribosomes and a circular molecule of DNA. Copyright © 2020, 2017, 2014 Pearson Education, Inc. All Rights Reserved  Cytoplasm of Eukaryotes (12 of 14) Membranous Organelles – Chloroplasts ▪ Light-harvesting structures found in photosynthetic eukaryotes – Use light energy to produce ATP ▪ Have two phospholipid bilayer membranes and DNA ▪ Have 70S ribosomes Copyright © 2020, 2017, 2014 Pearson Education, Inc. All Rights Reserved Table 3.5 Nonmembranous and Membranous Organelles of Cells (1 of 2) Blank General Function Prokaryotes Eukaryotes Nonmembranous Blank Blank Blank Organelles Ribosomes Protein synthesis Present in all Present in all Cytoskeleton Shape in prokaryotes; support, cytoplasmic Present in some Present in all streaming, and endocytosis in eukaryotes Centrosome Appears to play a role in mitosis, cytokinesis, Absent in all Present in and formation of flagella and cilia in animal animals cells Membranous Sequester chemical reactions within the cell Blank Blank Organelles Nucleus “Control center” of the cell Absent in all Present in all Endoplasmic reticulum Transport within the cell; lipid synthesis Absent in all Present in all Golgi bodies Exocytosis; secretion Absent in all Present in some Lysosomes Breakdown of nutrients; self-destruction of Absent in all Present in some damaged or aged cells Peroxisomes Neutralization of toxins Absent in all Present in some Vacuoles Storage Absent in all Present in some Copyright © 2020, 2017, 2014 Pearson Education, Inc. All Rights Reserved Table 3.5 Nonmembranous and Membranous Organelles of Cells (2 of 2) Blank General Function Prokaryotes Eukaryotes Vesicles Storage, digestion, transport Absent in all Present in all Mitochondria Aerobic ATP production Absent in all Present in most Chloroplasts Photosynthesis Absent in all, though Present in infoldings of cytoplasmic plants and membrane called algae photosynthetic lamellae have same function in photosynthetic prokaryotes Copyright © 2020, 2017, 2014 Pearson Education, Inc. All Rights Reserved Cytoplasm of Eukaryotes (13 of 14) Endosymbiotic Theory – Eukaryotes formed from union of small aerobic prokaryotes with larger anaerobic prokaryotes. – Smaller prokaryotes became internal parasites. ▪ Parasites lost ability to exist independently. ▪ Larger cell became dependent on parasites for aerobic ATP production. ▪ Aerobic prokaryotes evolved into mitochondria. ▪ Similar scenario for origin of chloroplasts Copyright © 2020, 2017, 2014 Pearson Education, Inc. All Rights Reserved Table 3.6 Comparison of Archaeal, Bacterial, and Eukaryotic Cells (1 of 2) Characteristic Archaea Bacteria Eukaryotes Nucleus Absent Absent Present Free organelles bound Absent in all Present in few Various types present in all; with phospholipid include ER, Golgi bodies, membranes lysosomes, mitochondria, and chloroplasts Glycocalyx Present Present as organized Present in some, e.g., capsule or unorganized slime surrounding some animal cells layer Motility Present in some Present in some Present in some; some have flagella, cilia, or Pseudopods Flagella Some have flagella, Some have flagella, each Some have flagella or cilia each composed of composed of basal body, composed of a “9 + 2” basal body, hook, and hook, and filament; flagella arrangement of microtubules; filament; flagella rotate rotate flagella and cilia undulate Cilia Absent in all Absent in all Present in some Fimbriae or pili Present in some Present in some Absent in all Hami Present in some Absent in all Absent in all Copyright © 2020, 2017, 2014 Pearson Education, Inc. All Rights Reserved Table 3.6 Comparison of Archaeal, Bacterial, and Eukaryotic Cells (2 of 2) Characteristic Archaea Bacteria Eukaryotes Cell wall Present in most; lack Present in most; composed Present in plants, algae, and peptidoglycan of peptidoglycan fungi Cytoplasmic Present in all Present in all Present in all membrane Cytosol Present in all Present in all Present in all Inclusions Present in most Present in most Present in some Endospores Absent in all Present in some Absent in all Ribosomes Small (70S) Small (70S) Large (80S) in cytosol and on ER, smaller (70S) in mitochondria and chloroplasts Chromosomes Commonly single and Commonly single and Linear and more than one circular circular chromosome per cell Copyright © 2020, 2017, 2014 Pearson Education, Inc. All Rights Reserved Cytoplasm of Eukaryotes (14 of 14) Tell Me Why – Colchicine is a drug that inhibits microtubule formation. Why does colchicine inhibit phagocytosis, movement of organelles within the cell, and formation of flagella and cilia? Copyright © 2020, 2017, 2014 Pearson Education, Inc. All Rights Reserved