BIOLOGY. Viruses CAMPBELL. Reece Urry Cain Wasserman Minorsky Jackson. Lecture Presentation by Nicole Tunbridge and Kathleen Fitzpatrick TENTH EDITION
|
|
- Rafe Turner
- 6 years ago
- Views:
Transcription
1 CAMPBELL BIOLOGY TENTH EDITION Reece Urry Cain Wasserman Minorsky Jackson 19 Viruses Lecture Presentation by Nicole Tunbridge and Kathleen Fitzpatrick
2 Figure 19.1 Are the viruses (red) budding from this cell alive?
3 Overview: A Borrowed Life Viruses called bacteriophages can infect and set in motion a genetic takeover of bacteria, such as Escherichia coli Viruses lead a kind of borrowed life between life-forms and chemicals The origins of molecular biology lie in early studies of viruses that infect bacteria Viruses were detected indirectly long before they were actually seen
4 The Discovery of Viruses: Scientific Inquiry Tobacco mosaic disease stunts growth of tobacco plants and gives their leaves a mosaic coloration In the late 1800s, researchers hypothesized that a particle smaller than bacteria caused the disease In 1935, Wendell Stanley confirmed this hypothesis by crystallizing the infectious particle, now known as tobacco mosaic virus (TMV)
5 Experiment Figure Extracted sap from tobacco plant with tobacco mosaic disease 2 Passed sap through a porcelain filter known to trap bacteria 3 Rubbed filtered sap on healthy tobacco plants 4 Healthy plants became infected
6 Structure of Viruses Viruses are the simplest biological systems. Viruses are not cells. Viruses are very small infectious particles consisting of nucleic acid enclosed in a protein coat and, in some cases, a membranous envelope Are viruses living or nonliving? $ --- Viruses cannot reproduce or carry out metabolic activities outside of a host cell. Most virologists would probably agree that viruses are not alive but lead a kind of borrowed life.
7 Viral Genomes Viruses genome of may consist of either double-stranded DNA, or single-stranded DNA, or double-stranded RNA,or single-stranded RNA, depending on the kind of virus. A virus is called a DNA virus or an RNA virus, according to the kind of nucleic acid that makes up its genome. The viral genome is usually organized as a single linear or circular molecule of nucleic acid. Viruses have between three and several thousand genes in their genome
8 Capsids and Envelopes A capsid is the protein shell that encloses the viral genome. Capsids are built from protein subunits called capsomeres. A capsid can have various structures. Viruses with Rod-shaped capsidsare called helical viruses. Adenoviruses have 252 identical proteins arranged into a polyhedral capsid with 20 triangular facts an icosahedron. Viruses that infect bacteria -bacteriophages or phages have the most complex capsids. Phages have an elongated capsid head that encloses their DNA and protein tail piece attaches the phage to the host and injects the phage DNA inside. Some viruses have accessory structures viral envelopes to help them infect their hosts. Viral envelope contain host cell phospholipids and membrane proteins as well as proteins and glycoproteins of viral origin A membranous envelope surrounds the capsids of flu viruses.
9 RNA Capsomere DNA Membranous envelope RNA Capsid Head DNA Capsomere of capsid Tail sheath Tail fiber Glycoprotein Glycoproteins nm nm (diameter) nm (diameter) nm 20 nm 50 nm 50 nm 50 nm (a) Tobacco mosaic (b) Adenoviruses (c) Influenza viruses (d) Bacteriophage T4 virus Figure 19.3 Viral structure
10 Viruses replicate only in host cells Viruses can replicate only within a host cell. An isolated virus is unable to reproduce or do anything else, except infect an appropriate host. An isolated virus is merely a packaged set of genes in transit from one host cell to another. Each type of virus can infect and parasitize only a limited range of host cells, called its host range.
11 General Features of Viral Replicative Cycles Once a viral genome enters a cell (the host), the host cell begins to manufacture viral proteins The virus makes use of host enzymes, ribosomes, trnas, amino acids, ATP, and other molecules Viral nucleic acid molecules and capsomeres spontaneously self-assemble into new viruses
12 1 Entry and uncoating DNA Capsid VIRUS 3 Transcription and manufacture of capsid proteins 2 Replication HOST CELL Viral DNA mrna Viral DNA Capsid proteins Figure Self-assembly of new virus particles and their exit from the cell
13 Replicative Cycles of Phages Phages are the best understood of all viruses Phages have two reproductive mechanisms: the lytic cycle and the lysogenic cycle
14 The Lytic Cycle The lytic cycle is a phage reproductive cycle that culminates in the death of the host cell The lytic cycle produces new phages and digests the host s cell wall, releasing the progeny viruses A phage that reproduces only by the lytic cycle is called a virulent phage Bacteria have defenses against phages, including restriction enzymes that recognize and cut up certain phage DNA
15 Fig The Lytic Cycle 5 5 Release: Phage enzymes damage the cell Wall, fluid enters the bacteria and it bursts. 1 Attachment: T4 uses its tail fibers 2 Entry of phage DNA and degradation of host DNA Phage assembly 4 Head Tail Tail fibers Assembly: 3 separate sets of proteins form phage heads, tails, and tail fibers. The phage genome is packaged into the capsid as it forms. 3 Synthesis of viral genomes and proteins using host machinery.
16 The Lysogenic Cycle The lysogenic cycle replicates the phage genome without destroying the host The viral DNA molecule is incorporated into the host cell s chromosome This integrated viral DNA is known as a prophage Every time the host divides, it copies the phage DNA and passes the copies to daughter cells An environmental signal can trigger the virus genome to exit the bacterial chromosome and switch to the lytic mode Phages that use both the lytic and lysogenic cycles are called temperate phages
17 Figure 19.6 The lytic and lysogenic cycles of phage λ, a temperate phage Phage Phage DNA Tail fiber The phage injects its DNA. Bacterial chromosome Phage DNA circularizes. Daughter cell with prophage Prophage exits chromosome. Many cell divisions create many infected bacteria. The cell lyses, releasing phages. Lytic cycle Lysogenic cycle Prophage Prophage is copied with bacterial chromosome. Phage DNA and proteins are synthesized and assembled. Phage DNA integrates into bacterial chromosome.
18 The lytic and lysogenic cycles Phage DNA The phage attaches to a host cell and injects its DNA. Bacterial chromosome Prophage Lytic cycle Virulent or temperate phage Destruction of host DNA Production of new phages Lysis of host cell causes releases of progeny phages Lysogenic cycle Temperate phage only Genome integrates into bacterial chromosome as prophage, which (1) is replicated and passed on to daughter cells and (2) can be induced to leave the chromosome and initiate a lytic cycle
19 Replicative Cycles of Animal Viruses There are two key variables used to classify viruses that infect animals An RNA or DNA genome A single-stranded or double-stranded genome Whereas few bacteriophages have an envelope or an RNA genome, many animal viruses have both
20 Table 19.1
21 Replitive Cycles of Animal Envelope Viruses Most animal viruses with RNA genomes have an envelope. Viruses equipped with an outer glycoprotein envelope use the envelope to enter the host cell. The envelope fuses with the host s membrane, transporting the capsid and the viral genome inside. In the reproductive cycle of an enveloped virus with an RNA genome, viral glycoproteins for new envelopes are made by ribosomes bound to the ER of the host cell, then modified by the host s Golgi apparatus. These glycoproteins are transported to the cell surface, where they wrap themselves in membrane as they bud from the cell. The viral envelope is thus derived from the host s plasma membrane, although viral genes specify some of the molecules in the membrane.
22 Capsid RNA HOST CELL Envelope (with glycoproteins) mrna Template Viral genome (RNA) Glycoproteins ER Capsid proteins Copy of genome (RNA) New virus Figure 19.7 The replicative cycle of an enveloped RNA virus
23 RNA as Viral Genetic Material In some viruses with single-stranded RNA (class IV), the genome acts as mrna and is translated into viral protein immediately after infection. In others (class V), the RNA genome serves as a template for complementary RNA strands, which function both as mrna and as templates for the synthesis of additional copies of genome RNA. All viruses that require RNA RNA synthesis to make mrna use a viral enzyme that is packaged with the genome inside the capsid. Retroviruses (class VI) have the most complicated life cycles. Retroviruses carry an enzyme called reverse transcriptase that transcribes DNA from an RNA template. This provides RNA DNA information flow.
24 HIV is a Retrovirus HIV (human immunodeficiency virus) is the retrovirus that causes AIDS (acquired immunodeficiency syndrome) HIV and other retroviruses are enveloped viruses that contain two identical molecules of single-stranded RNA and two molecules of reverse transcriptase. The reproductive cycle of HIV illustrates the pattern of infection and replication in a retrovirus. After HIV enters the host cell, reverse transcriptase molecules are released into the cytoplasm and catalyze the synthesis of viral DNA. The newly made viral DNA enters the cell s nucleus and is inserted as a permanent provirus into a chromosome. The host s RNA polymerase transcribes the proviral DNA into RNA molecules that can function both as mrna for the synthesis of viral proteins and as genomes for new virus particles released from the cell.
25 Glycoprotein Viral envelope Capsid Life Cycle of HIV HIV Membrane of white blood cell Reverse transcriptase HIV RNA (two identical strands) Viral RNA HOST CELL Reverse transcriptase RNA-DNA hybrid DNA RNA genome for the next viral generation Chromosomal DNA NUCLEUS Provirus mrna 0.25 µm HIV entering a cell New virus Figure 19.8 New HIV leaving a cell
26 The viral DNA that is integrated into the host genome is called a provirus. Unlike a prophage, a provirus remains a permanent resident of the host cell The host s RNA polymerase transcribes the proviral DNA into RNA molecules The RNA molecules function both as mrna for synthesis of viral proteins and as genomes for new Avirus particles released from the cell
27 Evolution of Viruses Viruses do not fit our definition of living organisms Since viruses can reproduce only within cells, they probably evolved as bits of cellular nucleic acid Candidates for the source of viral genomes are plasmids, circular DNA in bacteria and yeasts, and transposons, small mobile DNA segments Plasmids, transposons, and viruses are all mobile genetic elements Mimivirus, a double-stranded DNA virus, is the largest virus yet discovered There is controversy about whether this virus evolved before or after cells
28 Viruses, viroids, and prions are formidable pathogens in animals and plants Diseases caused by viral infections affect humans, agricultural crops, and livestock worldwide. Smaller, less complex entities called viroids and prions also cause disease in plants and animals, respectively Some viruses damage or kill cells by triggering the release of hydrolytic enzymes from lysosomes. Some viruses cause the infected cell to produce toxins that lead to disease symptoms. Others viruses have molecular components, such as envelope proteins, that are toxic. In some cases, viral damage is easily repaired (respiratory epithelium after a cold), but in others, infection causes permanent damage (nerve cells after polio). Many of the temporary symptoms associated with a viral infection result from the body s own efforts at defending itself against infection.
29 The Immune System The immune system is the body s natural defense mechanism against viral and other infections. Vaccines are harmless variants or derivatives of pathogenic microbes, that stimulate the immune system to mount defenses against the actual pathogen. Vaccines can prevent certain viral illnesses. Vaccination has eradicated smallpox. Effective vaccines are available against polio, measles, rubella, mumps, hepatitis B, and a number of other viral diseases. Antiviral drugs can help to treat, though not cure, viral infections. Viral infections cannot be treated by antibiotics. Most antiviral drugs resemble nucleosides and interfere with viral nucleic acid synthesis.
30 Emerging new Viruses The emergence of these new viral diseases is due to three processes: mutation; the dissemination of a viral disease from a small, isolated population; and the spread of existing viruses from one species to another. RNA viruses tend to have high mutation rates because replication of their nucleic acid lacks proofreading. Some mutations create new viral strains with sufficient genetic differences from earlier strains that they can infect individuals who had acquired immunity to these earlier strains. Flu epidemics are caused by new strains of influenza virus to which people have little immunity. H1N1 virus of Influenza outbreak from Mexico recently. These strains can cause pandemics, global epidemics. The avian flu is a virus that recently appeared in humans and originated in wild birds Emerging viruses are those that appear suddenly or suddenly come to the attention of scientists like Severe acute respiratory syndrome (SARS) recently appeared in China.
31 Figure µm (a) 2009 pandemic H1N1 influenza A virus (b) 2009 pandemic screening (c) 1918 flu pandemic
32 Dissemination of viral disease A viral disease can spread from a small, isolated population to become a widespread epidemic. For example, AIDS went unnamed and virtually unnoticed for decades before spreading around the world. Technological and social factors, including affordable international travel, blood transfusion technology, sexual promiscuity, and the abuse of intravenous drugs, allowed a previously rare disease to become a global scourge.
33 Viral spread between species A third source of new viral diseases is the spread of existing viruses from one host species to another. It is estimated that about three-quarters of new human diseases originated in other animals. For example, a species of bat has been identified as the likely natural initiator of the SARS virus.
34 Flu epidemics illustrate the effects of viruses moving between species There are three types of influenza virus: Types B and C- infect only humans and have never caused an epidemic Type A- which infects a range of animals. Influenza A strains have caused three major flu epidemics among humans in the last 100 years. The worst was the Spanish flu pandemic of , which killed 40 million people. This strain probably originated in birds and then passed between different species, undergoing mutations. In animals infected with multiple strains of flu virus, the different strains underwent genetic recombination, leading to the emergence of a virus capable of infecting human cells. Humans lacked immunity to this novel, virulent recombinant virus.
35 Viral Diseases in Plants Figure More than 2,000 types of viral diseases of plants are known and cause spots on leaves and fruits, stunted growth, and damaged flowers or roots Most plant viruses have an RNA genome Viruses can spread from one plant cell to another through plasmodesmata. Plant viruses spread disease in two major modes: Horizontal transmission, entering through damaged cell walls Vertical transmission, inheriting the virus from a parent
36 Viroids and Prions: The Simplest Infectious Agents Viroids are circular RNA molecules that infect plants and disrupt their growth. These small RNA molecules can disrupt plant metabolism and stunt plant growth, perhaps by causing errors in the regulatory systems that control plant growth. Viroids show that a single molecule can act as an infectious agent to spread disease. Viroids are small circular RNA molecules that infect plants and disrupt their growth.
37 Prions are infectious proteins that spread disease Prions are slow-acting (10 year onset), virtually indestructible infectious proteins that cause brain diseases in mammals Prions propagate by converting normal proteins into the prion version Scrapie in sheep, mad cow disease, and Creutzfeldt- Jakob disease in humans are all caused by prions Prions are likely transmitted in food. Prions are virtually indestructible. They are not destroyed or deactivated by heating to normal cooking temperatures. There is no known cure for prion diseases.
38 How can a protein be a transmissible pathogen? Fig How prions (probably) propagate: 1. Prions are just misfolded normal proteins. 2. When a prion comes in contact with a normally folded protein, it might induce that protein to fold into the same abnormal shape. 3. $ --- Aggregates of misfolded (prion) protiens may just cause brain cells to be disfunctional and eventually brain degeneration will occur.
39 H1N1 flu vaccination Figure 19.UN01c
Lecture 2: Virology. I. Background
Lecture 2: Virology I. Background A. Properties 1. Simple biological systems a. Aggregates of nucleic acids and protein 2. Non-living a. Cannot reproduce or carry out metabolic activities outside of a
More informationOverview: Chapter 19 Viruses: A Borrowed Life
Overview: Chapter 19 Viruses: A Borrowed Life Viruses called bacteriophages can infect and set in motion a genetic takeover of bacteria, such as Escherichia coli Viruses lead a kind of borrowed life between
More informationChapter 18. Viral Genetics. AP Biology
Chapter 18. Viral Genetics 2003-2004 1 A sense of size Comparing eukaryote bacterium virus 2 What is a virus? Is it alive? DNA or RNA enclosed in a protein coat Viruses are not cells Extremely tiny electron
More information19 Viruses BIOLOGY. Outline. Structural Features and Characteristics. The Good the Bad and the Ugly. Structural Features and Characteristics
9 Viruses CAMPBELL BIOLOGY TENTH EDITION Reece Urry Cain Wasserman Minorsky Jackson Outline I. Viruses A. Structure of viruses B. Common Characteristics of Viruses C. Viral replication D. HIV Lecture Presentation
More informationChapter 19: Viruses. 1. Viral Structure & Reproduction. What exactly is a Virus? 11/7/ Viral Structure & Reproduction. 2.
Chapter 19: Viruses 1. Viral Structure & Reproduction 2. Bacteriophages 3. Animal Viruses 4. Viroids & Prions 1. Viral Structure & Reproduction Chapter Reading pp. 393-396 What exactly is a Virus? Viruses
More informationChapter 19: Viruses. 1. Viral Structure & Reproduction. 2. Bacteriophages. 3. Animal Viruses. 4. Viroids & Prions
Chapter 19: Viruses 1. Viral Structure & Reproduction 2. Bacteriophages 3. Animal Viruses 4. Viroids & Prions 1. Viral Structure & Reproduction Chapter Reading pp. 393-396 What exactly is a Virus? Viruses
More informationAP Biology. Viral diseases Polio. Chapter 18. Smallpox. Influenza: 1918 epidemic. Emerging viruses. A sense of size
Hepatitis Viral diseases Polio Chapter 18. Measles Viral Genetics Influenza: 1918 epidemic 30-40 million deaths world-wide Chicken pox Smallpox Eradicated in 1976 vaccinations ceased in 1980 at risk population?
More informationViral reproductive cycle
Lecture 29: Viruses Lecture outline 11/11/05 Types of viruses Bacteriophage Lytic and lysogenic life cycles viruses viruses Influenza Prions Mad cow disease 0.5 µm Figure 18.4 Viral structure of capsid
More information11/15/2011. Outline. Structural Features and Characteristics. The Good the Bad and the Ugly. Viral Genomes. Structural Features and Characteristics
Chapter 19 - Viruses Outline I. Viruses A. Structure of viruses B. Common Characteristics of Viruses C. Viral replication D. HIV II. Prions The Good the Bad and the Ugly Viruses fit into the bad category
More informationAP Biology Reading Guide. Concept 19.1 A virus consists of a nucleic acid surrounded by a protein coat
AP Biology Reading Guide Name Chapter 19: Viruses Overview Experimental work with viruses has provided important evidence that genes are made of nucleic acids. Viruses were also important in working out
More informationChapter 19. Viruses. Concept 19.1 A virus consists of a nucleic acid surrounded by a protein coat.
Chapter 19 Viruses Lecture Outline Overview: A Borrowed Life Viruses are the simplest biological systems. Most viruses are little more than aggregates of nucleic acids and protein genes in a protein coat.
More informationChapter 19: The Genetics of Viruses and Bacteria
Chapter 19: The Genetics of Viruses and Bacteria What is Microbiology? Microbiology is the science that studies microorganisms = living things that are too small to be seen with the naked eye Microorganisms
More information1. Virus 2. Capsid 3. Envelope
VIRUSES BIOLOGY II VOCABULARY- VIRUSES (22 Words) 1. Virus 2. Capsid 3. Envelope 4. Provirus 5. Retrovirus 6. Reverse transcriptase 7. Bacteriophage 8. Lytic Cycle 9. Virulent 10. Lysis 11. Lysogenic Cycle
More informationSection A: The Genetics of Viruses
CHAPTER 18 MICROBIAL MODELS: THE GENETICS OF VIRUSES AND BACTERIA Section A: The Genetics of Viruses 1. Researchers discovered viruses by studying a plant disease 2. A virus is a genome enclosed in a protective
More informationVIRUSES. 1. Describe the structure of a virus by completing the following chart.
AP BIOLOGY MOLECULAR GENETICS ACTIVITY #3 NAME DATE HOUR VIRUSES 1. Describe the structure of a virus by completing the following chart. Viral Part Description of Part 2. Some viruses have an envelope
More informationSome living things are made of ONE cell, and are called. Other organisms are composed of many cells, and are called. (SEE PAGE 6)
Section: 1.1 Question of the Day: Name: Review of Old Information: N/A New Information: We tend to only think of animals as living. However, there is a great diversity of organisms that we consider living
More informationViruses defined acellular organisms genomes nucleic acid replicate inside host cells host metabolic machinery ribosomes
The Viruses Viruses Viruses may be defined as acellular organisms whose genomes consist of nucleic acid, obligately replicate inside host cells using host metabolic machinery and ribosomes to form a pool
More informationChapter 6- An Introduction to Viruses*
Chapter 6- An Introduction to Viruses* *Lecture notes are to be used as a study guide only and do not represent the comprehensive information you will need to know for the exams. 6.1 Overview of Viruses
More information19/06/2013. Viruses are not organisms (do not belong to any kingdom). Viruses are not made of cells, have no cytoplasm, and no membranes.
VIRUSES Many diseases of plants and animals are caused by bacteria or viruses that invade the body. Bacteria and viruses are NOT similar kinds of micro-organisms. Bacteria are classified as living organisms,
More informationCh. 19 Viruses & Bacteria: What Is a Virus?
Ch. 19 Viruses & Bacteria: What Is a Virus? A virus is an invective agent consisting of a nucleic acid in a protein coat, able to multiply only within the living cells of a host. A bacteriophage ( bacteria
More informationMicrobiology Chapter 7 Viruses
Microbiology Chapter 7 Viruses 7:1 Viral Structure and Classification VIRUS: a biological particle composed of genetic material (DNA or RNA) encased in a protein coat CAPSID: protein coat surrounding a
More informationUnit 4 Student Guided Notes
Structure of Viruses Discovery of the Virus Unit 4 Student Guided Notes Many human epidemics were well documented and observed in history, but. The following 3 discoveries shaped our knowledge of viruses
More informationA virus consists of a nucleic acid surrounded by a protein coat. [2]
GUIDED READING - Ch. 19 - VIRUSES NAME: Please print out these pages and HANDWRITE the answers directly on the printouts. Typed work or answers on separate sheets of paper will not be accepted. Importantly,
More informationUnit 13.2: Viruses. Vocabulary capsid latency vaccine virion
Unit 13.2: Viruses Lesson Objectives Describe the structure of viruses. Outline the discovery and origins of viruses. Explain how viruses replicate. Explain how viruses cause human disease. Describe how
More informationSECTION 25-1 REVIEW STRUCTURE. 1. The diameter of viruses ranges from about a. 1 to 2 nm. b. 20 to 250 nm. c. 1 to 2 µm. d. 20 to 250 µm.
SECTION 25-1 REVIEW STRUCTURE VOCABULARY REVIEW Define the following terms. 1. virus 2. capsid 3. retrovirus 4. viroid 5. prion MULTIPLE CHOICE Write the correct letter in the blank. 1. The diameter of
More informationWarts are a skin virus!
Viruses Warts are a skin virus! Herpes mouth virus: Other Viral Diseases Measles Polio Smallpox Influenza Hepatitis B Virus Viruses & Cancer Human Papilloma Virus HPV Tree Man - HPV Is a Virus a Living
More information18.2 Viruses and Prions
KEY CONCEPT Infections can be caused in several ways. Viruses, bacteria, viroids, and prions can all cause infection. Any disease-causing agent is called a pathogen. 1 nanometer (nm) = one billionth of
More informationSTRUCTURE, GENERAL CHARACTERISTICS AND REPRODUCTION OF VIRUSES
STRUCTURE, GENERAL CHARACTERISTICS AND REPRODUCTION OF VIRUSES Introduction Viruses are noncellular genetic elements that use a living cell for their replication and have an extracellular state. Viruses
More informationVirology Introduction. Definitions. Introduction. Structure of virus. Virus transmission. Classification of virus. DNA Virus. RNA Virus. Treatment.
DEVH Virology Introduction Definitions. Introduction. Structure of virus. Virus transmission. Classification of virus. DNA Virus. RNA Virus. Treatment. Definitions Virology: The science which study the
More informationDate. Student Name. Prompt: This passage is called Characteristics of Viruses. It is about viruses.
Student Name Characteristics of Viruses--Part I Level High School - Science Date _ Prompt: This passage is called Characteristics of Viruses. It is about viruses. Similarities and Differences Between Viruses
More informationSize nm m m
1 Viral size and organization Size 20-250nm 0.000000002m-0.000000025m Virion structure Capsid Core Acellular obligate intracellular parasites Lack organelles, metabolic activities, and reproduction Replicated
More informationViruses. Objectives At the end of this sub section students should be able to:
Name: 3.5 Responses to Stimuli Objectives At the end of this sub section students should be able to: 3.5.4 Viruses 1. Explain the problem of defining what a virus is - living or non-living? 2. show you
More informationViruses. Non-cellular organisms. Premedical - Biology
Viruses Non-cellular organisms Premedical - Biology Size the smallest 20 nm and more Non-cellular: viruses are infectious particles plant, animal, bacterial = bacteriophages virion = nucleic acid + protein
More informationChapter13 Characterizing and Classifying Viruses, Viroids, and Prions
Chapter13 Characterizing and Classifying Viruses, Viroids, and Prions 11/20/2017 MDufilho 1 Characteristics of Viruses Viruses Minuscule, acellular, infectious agent having either DNA or RNA Cause infections
More informationViruses Tomasz Kordula, Ph.D.
Viruses Tomasz Kordula, Ph.D. Resources: Alberts et al., Molecular Biology of the Cell, pp. 295, 1330, 1431 1433; Lehninger CD Movie A0002201. Learning Objectives: 1. Understand parasitic life cycle of
More informationIntroduction to viruses. BIO 370 Ramos
Introduction to viruses BIO 370 Ramos 1 2 General Structure of Viruses Size range most
More information19 2 Viruses Slide 1 of 34
1 of 34 What Is a Virus? What Is a Virus? Viruses are particles of nucleic acid, protein, and in some cases, lipids. Viruses can reproduce only by infecting living cells. 2 of 34 What Is a Virus? Viruses
More informationBacteriophage Reproduction
Bacteriophage Reproduction Lytic and Lysogenic Cycles The following information is taken from: http://student.ccbcmd.edu/courses/bio141/lecguide/unit3/index.html#charvir Bacteriophage Structure More complex
More informationPart I. Content: History of Viruses. General properties of viruses. Viral structure. Viral classifications. Virus-like agents.
Viruses Part I Content: History of Viruses. General properties of viruses. Viral structure. Viral classifications. Virus-like agents. History Through the 1800s, many scientists discovered that something
More informationName Class Date. Infection in which a virus inserts its nucleic acid into the DNA of the host cell and is duplicated with the cell s DNA
Name Class Date 20.1 Viruses Lesson Objectives Explain how viruses reproduce. Explain how viruses cause infection. BUILD Vocabulary A. The chart below shows key terms from the lesson with their definitions.
More informationViruses 101., and concluded that living organisms do not crystallize. In other words,.
Viruses 101 In 1897, Dutch scientist called tiny particles in the liquid extracted from a plant disease, which is the Latin word for. In 1935, American biochemist isolated crystals of, and concluded that
More information2.1 VIRUSES. 2.1 Learning Goals
2.1 VIRUSES 2.1 Learning Goals To understand the structure, function, and how Viruses replicate To understand the difference between Viruses to Prokaryotes and Eukaryotes; namely that viruses are not classified
More informationChapter 13 Viruses, Viroids, and Prions. Biology 1009 Microbiology Johnson-Summer 2003
Chapter 13 Viruses, Viroids, and Prions Biology 1009 Microbiology Johnson-Summer 2003 Viruses Virology-study of viruses Characteristics: acellular obligate intracellular parasites no ribosomes or means
More informationCharacterizing and Classifying Viruses, Viroids, and Prions
PowerPoint Lecture Presentations prepared by Mindy Miller-Kittrell, North Carolina State University C H A P T E R 13 Characterizing and Classifying Viruses, Viroids, and Prions SLOs What are the Characteristics
More informationVirus and Prokaryotic Gene Regulation - 1
Virus and Prokaryotic Gene Regulation - 1 We have discussed the molecular structure of DNA and its function in DNA duplication and in transcription and protein synthesis. We now turn to how cells regulate
More informationStructure & Function of Viruses
Structure & Function of Viruses Discovery of Viruses Louis Pasteur- looks for a causative agent for rabies, says too small, can not find it 1892 Dimitry Ivanosky- studies tobacco disease, can not find
More information18.2. Viral Structure and Reproduction. Viruses differ in shape and in ways of entering
18.2 Viral Structure and Reproduction VOCABULARY bacteriophage lytic infection lysogenic infection prophage compare the structures of viruses to cells, describe viral reproduction, and describe the role
More informationDr. Gary Mumaugh. Viruses
Dr. Gary Mumaugh Viruses Viruses in History In 1898, Friedrich Loeffler and Paul Frosch found evidence that the cause of foot-and-mouth disease in livestock was an infectious particle smaller than any
More informationBiol115 The Thread of Life"
Biol115 The Thread of Life" Lecture 9" Gene expression and the Central Dogma"... once (sequential) information has passed into protein it cannot get out again. " ~Francis Crick, 1958! Principles of Biology
More informationViruses. and Prions. ct o, ni, 21. Viruses. Table 2. Essential Questions
ct o, ni, 21 Essential Questions ;1 What is the general structure of a virus? What are similarities and differences in the lytic cycle, the lysogenic cycle, and retroviral replication? I What is the relationship
More informationChapter 13B: Animal Viruses
Chapter 13B: Animal Viruses 1. Overview of Animal Viruses 2. DNA Viruses 3. RNA Viruses 4. Prions 1. Overview of Animal Viruses Life Cycle of Animal Viruses The basic life cycle stages of animal viruses
More informationViral structure م.م رنا مشعل
Viral structure م.م رنا مشعل Viruses must reproduce (replicate) within cells, because they cannot generate energy or synthesize proteins. Because they can reproduce only within cells, viruses are obligate
More informationLESSON 4.4 WORKBOOK. How viruses make us sick: Viral Replication
DEFINITIONS OF TERMS Eukaryotic: Non-bacterial cell type (bacteria are prokaryotes).. LESSON 4.4 WORKBOOK How viruses make us sick: Viral Replication This lesson extends the principles we learned in Unit
More informationViruses. Picture from:
Viruses Understand the structure of bacteriophages & human immunodeficiency virus (HIV) Appreciate that viruses replicate in host cells (thereby destroying them) Picture from: http://eands.caltech.edu/articles/lxvii1/viruses.html
More informationHistory of Virology. Russian Bacteriologist Dimitri Iwanowski TMD tobacco mosaic disease TMV isolated and purified
Viruses & Prions Viruses Virus miniscule, acellular, infectious agent having one or several pieces of either DNA or RNA No cytoplasmic membrane, cytosol, organelles Cannot carry out any metabolic pathway
More informationLecture 5 (Ch6) - Viruses. Virus Characteristics. Viral Host Range
Lecture 5 (Ch6) - Viruses Topics Characteristics Structure/Classification Multiplication Cultivation and replication Non-viral infectious agents Treatment 1 Virus Characteristics obligate intracellular
More informationHuman Genome Complexity, Viruses & Genetic Variability
Human Genome Complexity, Viruses & Genetic Variability (Learning Objectives) Learn the types of DNA sequences present in the Human Genome other than genes coding for functional proteins. Review what you
More informationDiscovery of. 1892: Russian biologist Dmitri Ivanovsky publishes. 1931: first images of viruses obtained using
Discovery of (1884: invention of the Chamberland filter with pores smaller than bacteria) 1892: Russian biologist Dmitri Ivanovsky publishes a paper in which shows that extracts from diseased tobacco plants
More informationNucleic acid: singled stranded, double stranded, RNA, or DNA, linear or circular. Capsid: protein coat that is most of the mass of the virus.
Viruses General Characteristics of Viruses 1. Depending on view may be regarded as exceptionally complex aggregates of nonliving chemicals or as exceptionally simple living microbes. 2. Contain a single
More informationThe Zombies of the Scientific Community Viruses and Other Acellular Infectious Agents. Acellular Agents
viruses protein and nucleic acid viroids RNA virusoids RNA prions proteins The Zombies of the Scientific Community Viruses and Other Acellular Infectious Agents Acellular Agents Viruses major cause of
More informationChapter 12: Acellular Agents: Viruses, Viroids and Prions
Chapter 12: Acellular Agents: Viruses, Viroids and Prions Viruses Viruses are acellular infectious agents that are much smaller than bacteria and are usually measured in nanometers (Figure 12.1). They
More informationViruses. The image in Figure 19.1 shows a remarkable event: On the left is a human immune. A Borrowed Life KEY CONC EPTS
19 Viruses KEY CONC EPTS 19.1 A virus consists of a nucleic acid surrounded by a protein coat 19.2 Viruses replicate only in host cells 19.3 Viruses, viroids, and prions are formidable pathogens in animals
More informationViruses A virus consists of a nucleic acid surrounded by a protein coat
19 Viruses KEY CONCEPTS 0.5 mm Figure 19.1 Are the tiny viruses infecting this E. coli cell alive? 19.1 A virus consists of a nucleic acid surrounded by a protein coat 19.2 Viruses replicate only in host
More informationLESSON 4.6 WORKBOOK. Designing an antiviral drug The challenge of HIV
LESSON 4.6 WORKBOOK Designing an antiviral drug The challenge of HIV In the last two lessons we discussed the how the viral life cycle causes host cell damage. But is there anything we can do to prevent
More informationStarting with MICROBIOLOGY
Starting with MICROBIOLOGY Micro means very small and biology is the study of living things. Microbes are the oldest form of life on Earth. They've been here for 3.8 billion years! Microbes live everywhere.
More informationChapter 21: Prokaryotes & Viruses
Chapter 21: Prokaryotes & Viruses Microorganisms Single-celled organisms that are too small to be seen without a microscope Bacteria are the smallest living organisms Viruses are smaller but are not alive
More informationViruses and Prions (Chapter 13) Lecture Materials for Amy Warenda Czura, Ph.D. Suffolk County Community College Eastern Campus
Viruses and Prions (Chapter 13) Lecture Materials for Amy Warenda Czura, Ph.D. Suffolk County Community College Eastern Campus Primary Source for figures and content: Tortora, G.J. Microbiology An Introduction
More informationPHARMACEUTICAL MICROBIOLOGY JIGAR SHAH INSTITUTE OF PHARMACY NIRMA UNIVERSITY
PHARMACEUTICAL MICROBIOLOGY JIGAR SHAH INSTITUTE OF PHARMACY NIRMA UNIVERSITY VIRUS - HISTORY In 1886, the Dutch Chemist Adolf Mayer showed TMD In 1892, the Russian Bactriologist Dimtri Iwanowski isolate
More informationViruses. Rotavirus (causes stomach flu) HIV virus
Viruses Rotavirus (causes stomach flu) HIV virus What is a virus? A virus is a microscopic, infectious agent that may infect any type of living cell. Viruses must infect living cells in order to make more
More informationGeneral Virology I. Dr Esam Ibraheem Azhar (BSc, MSc, Ph.D Molecular Medical Virology) Asst. Prof. Medical Laboratory Technology Department
General Virology I Dr Esam Ibraheem Azhar (BSc, MSc, Ph.D Molecular Medical Virology) Asst. Prof. Medical Laboratory Technology Department ١ General Virology I Lecture Outline Introduction istory Definition
More informationCharacterizing and Classifying Viruses, Viroids, and Prions
Characterizing and Classifying Viruses, Viroids, and Prions CHAPTER SUMMARY Viruses, viroids, and prions are acellular (noncellular) disease-causing agents that lack cell structure and cannot metabolize,
More informationRevisiting the Definition of Living Thing
Biology of Viruses (Ch 0 p77 and 88-9) What do you already know about viruses? Revisiting the Definition of Living Thing How did we define a living thing? H0 DOMAIN ARCHAEA virus So, if the Cell Theory
More informationBiology 350: Microbial Diversity
Biology 350: Microbial Diversity Strange Invaders: Viruses, viroids, and prions. Lecture #27 7 November 2007-1- Notice handouts and announcements for today: Outline and study questions A 1999 paper discussing
More informationThe prokaryotic domains
Diversity of Bacteria, Archaea, and Viruses Chapter 19 The prokaryotic domains Bacteria Three types of structure Spherical, rod-shaped, and spiral Archaea Many are extremophilic Prefer to live in very
More informationLESSON 1.4 WORKBOOK. Viral sizes and structures. Workbook Lesson 1.4
Eukaryotes organisms that contain a membrane bound nucleus and organelles. Prokaryotes organisms that lack a nucleus or other membrane-bound organelles. Viruses small, non-cellular (lacking a cell), infectious
More informationViruses. An Illustrated Guide to Viral Life Cycles to Accompany Lecture. By Noel Ways
Viruses An Illustrated Guide to Viral Life Cycles to Accompany Lecture By Noel Ways Viral Life Cycle Step #1, Adhesion: During adhesion, specific receptors for specific molecules on potential host cell
More information8/13/2009. Diseases. Disease. Pathogens. Domain Bacteria Characteristics. Bacteria Shapes. Domain Bacteria Characteristics
Disease Diseases I. Bacteria II. Viruses including Biol 105 Lecture 17 Chapter 13a are disease-causing organisms Domain Bacteria Characteristics 1. Domain Bacteria are prokaryotic 2. Lack a membrane-bound
More informationViruses, Viroids, and Prions
2.2 Figure 1 Human infl uenza viruses cause seasonal fl u. It would take 10 million viruses placed side by side to cover a distance of 1 mm. virus a small infectious particle containing genetic material
More informationChapter 08 Lecture Outline
Chapter 08 Lecture Outline See separate PowerPoint slides for all figures and tables preinserted into PowerPoint without notes. Copyright 2016 McGraw-Hill Education. Permission required for reproduction
More informationVIROIDS, PRIONS. Infectious Stage When virus infects a cell, nucleic acid must be uncoated and gain access to metabolic machinery of cell.
VIROIDS, PRIONS A virus is a small infectious agent that can replicate only inside the living cells of organisms. Most viruses are too small to be seen directly with a light microscope. Viruses infect
More information5/6/17. Diseases. Disease. Pathogens. Domain Bacteria Characteristics. Bacteria Viruses (including HIV) Pathogens are disease-causing organisms
5/6/17 Disease Diseases I. II. Bacteria Viruses (including HIV) Biol 105 Chapter 13a Pathogens Pathogens are disease-causing organisms Domain Bacteria Characteristics 1. Domain Bacteria are prokaryotic.
More informationCharacterizing and Classifying Viruses, Viroids, and Prions
PowerPoint Lecture Presentations prepared by Mindy Miller-Kittrell, North Carolina State University Modified by Ossi Turunen, Aalto University C H A P T E R 13 Characterizing and Classifying Viruses, Viroids,
More informationWHY? Viruses are considered non-living because they do:
Viruses What is a Virus? Non-living particle WHY? Viruses are considered non-living because they do: NOT Carry out metabolism NOT Grow or develop NOT Replicate without the help of a living cell (host).
More informationMONTGOMERY COUNTY COMMUNITY COLLEGE CHAPTER 13: VIRUSES. 1. Obligate intracellular parasites that multiply in living host cells
MONTGOMERY COUNTY COMMUNITY COLLEGE CHAPTER 13: VIRUSES I. CHARACTERISTICS OF VIRUSES A. General Characteristics 1. Obligate intracellular parasites that multiply in living host cells 2. Contain a single
More informationChapter 20. Table of Contents. Section 1 Viruses. Section 2 Bacteria. Viruses and Bacteria
Viruses and Bacteria Table of Contents Section 1 Viruses Section 2 Bacteria Section 1 Viruses Objectives Describe why a virus is not considered a living organism. Describe the basic structure of a virus.
More informationHistory electron microscopes
Viruses History Through the 1800s, many scientists discovered that something smaller than bacteria could cause disease and they called it virion (Latin word- poison) In the 1930s, after the invention of
More informationSTAAR Biology: Assessment Activities. Cell Structure and Function. The Charles A. Dana Center at The University of Texas at Austin
Cell Structure and Function Viruses: Structure, Replication, and Disease 69 70 Cell Structure and Function Teacher Pages Purpose The purpose of this station is to reinforce students understanding of the
More information1/29/2013. Viruses and Bacteria. Infectious Disease. Pathogens cause disease by: Chapters 16 and 17
Viruses and Bacteria Chapters 16 and 17 Infectious Disease Caused by the invasion of a host by agents whose activities harm the host s tissues Can be transmitted to others Pathogen microorganisms that
More informationViral Genetics. BIT 220 Chapter 16
Viral Genetics BIT 220 Chapter 16 Details of the Virus Classified According to a. DNA or RNA b. Enveloped or Non-Enveloped c. Single-stranded or double-stranded Viruses contain only a few genes Reverse
More informationPurpose: To describe the characteristics of viruses and how they infect a host cell.
Intro to Viruses Group Worksheet Name: Per: # Purpose: To describe the characteristics of viruses and how they infect a host cell. Directions: Discuss the following questions as a group and use the resources
More informationI. Bacteria II. Viruses including HIV. Domain Bacteria Characteristics. 5. Cell wall present in many species. 6. Reproduction by binary fission
Disease Diseases I. Bacteria II. Viruses including are disease-causing organisms Biol 105 Lecture 17 Chapter 13a Domain Bacteria Characteristics 1. Domain Bacteria are prokaryotic 2. Lack a membrane-bound
More informationLEC 2, Medical biology, Theory, prepared by Dr. AYAT ALI
General Characteristics, Structure and Taxonomy of Viruses Viruses A virus is non-cellular organisms made up of genetic material and protein that can invade living cells. They are considered both a living
More informationVirology. *Viruses can be only observed by electron microscope never by light microscope. The size of the virus: nm in diameter.
Virology We are going to start with general introduction about viruses, they are everywhere around us; in food; within the environment; in direct contact to etc.. They may cause viral infection by itself
More informationVirus Infections and Hosts
OpenStax-CNX module: m44597 1 Virus Infections and Hosts OpenStax College This work is produced by OpenStax-CNX and licensed under the Creative Commons Attribution License 3.0 By the end of this section,
More informationLecture Guide Viruses (CH13)
Lecture Guide Viruses (CH13) This chapter is on the general characteristics of viruses and focuses on both bacterial and animal viruses and their life cycles. Let s start with a quick look at the history
More informationVirus Basics. General Characteristics of Viruses. Chapter 13 & 14. Non-living entities. Can infect organisms of every domain
Virus Basics Chapter 13 & 14 General Characteristics of Viruses Non-living entities Not considered organisms Can infect organisms of every domain All life-forms Commonly referred to by organism they infect
More information7.013 Spring 2005 Problem Set 7
MI Department of Biology 7.013: Introductory Biology - Spring 2005 Instructors: Professor Hazel Sive, Professor yler Jacks, Dr. Claudette Gardel 7.013 Spring 2005 Problem Set 7 FRIDAY May 6th, 2005 Question
More informationViruses, Viroids, and Prions
PowerPoint Lecture Presentations prepared by Bradley W. Christian, McLennan Community College C H A P T E R 13 Viruses, Viroids, and Prions General Characteristics of Viruses Obligatory intracellular parasites
More informationBIOL*1090 Introduction To Molecular and Cellular Biology Fall 2014
Last time... BIOL*1090 Introduction To Molecular and Cellular Biology Fall 2014 Lecture 3 - Sept. 15, 2014 Viruses Biological Membranes Karp 7th ed: Chpt. 4; sections 4-1, 4-3 to 4-7 1 2 VIRUS Non-cellular
More informationVirus Basics. General Characteristics of Viruses 5/9/2011. General Characteristics of Viruses. Chapter 13 & 14. Non-living entities
Virus Basics Chapter 13 & 14 General Characteristics of Viruses Non-living entities Not considered organisms Can infect organisms of every domain All life-formsf Commonly referred to by organism they infect
More information