VIRUSES

LESSON OBJECTIVES  Learning Goals  Yesterday’s Recap  Minds ON  Virus Lesson (Specifics and Clips)

LEARNING GOALS  We are / will be learning to…  Analyze the risks and benefits of human intervention (e.g. pesticide use, fish stocking, tree planting, etc.)  Analyze how climate change could impact the diversity of living things (e.g. Global warming, increase in precipitation)  Become familiar with terms such as: species diversity, structural diversity, bacteria, fungi, binomial nomenclature, morphology  Classify, apply, and draw dichotomous keys to identify and classify organisms according to kingdom  Explain concepts of taxonomic rank such as genus, species and taxon viruses  Compare/contrast characteristics of prokaryotes, eukaryotes and viruses  Compare/contrast anatomical and physiological characteristics of organisms representative of each kingdom  Explain structural and functional changes of organisms as they have evolved over time  Explain why biodiversity is important for maintaining viable ecosystems

YESTERDAY’S RECAP  Bacteria Characteristics: single cell, prokaryote, anatomy Shapes and groupings Gram Staining (Gram +, Gram -) Cell Movement: Flagellum, Cilia, Non-Motile Bacterial Respiration: Aerobic, anaerobic, obligate aerobe, obligate anaerobe, facultative anaerobes Bacteria Metabolism: autotroph, heterotroph, chemotroph Bacteria terms Reproduction of bacteria: binary fission, spores, conjugation Characteristics: Archaebacteria, eubacteria

MINDS ON  News article News article link-between-feed-and-pig-virus/article /  Cell Phones

WHAT IS A VIRUS?  Latin: toxin, poison  a microscopic organism consisting of genetic material (RNA or DNA) surrounded by a protein, lipid (fat), or glycoprotein coat.  Exists between living and non-living (lacks characteristics of six Kingdoms)  Parasitic existence Source: Medical News Today

EXAMPLES OF VIRUSES  Measles  Measles, also known as Rubeola or morbilli, is a highly infectious illness caused by a virus - a viral infection caused by the rubeola virus  AIDS  AIDS (Acquired immune deficiency syndrome or acquired immunodeficiency syndrome) is a disease caused by a virus called HIV (Human Immunodeficiency Virus). The illness alters the immune system. This susceptibility worsens as the disease progresses.  SARS  SARS stands for Severe Acute Respiratory Syndrome. It is a contagious disease that is caused by the SARS Coronavirus (SARS CoV) and typically leads to a potentially fatal form of pneumonia. Source: Medical News Today

CHARACTERISTICS OF A VIRUS  Size: nm(nanometers)  Make: Mostly of nucleic acid and capsid Capsid: Protein covering (made of hundreds of protein molecules); makes up 95% of virus Nucleic acid: Single strand of DNA or RNA

VIRUS SHAPES Bacteriophage: Bacteriophage: most complex and largest ; attack and infect bacteria

VIRUS SPECIFICITY  Viruses must enter cells to carry out life processes.  Not every virus is considered to be disease- causing.  Viruses are generally selective, and in most cases, specific viruses enter only specific host cells.

VIRUS REPRODUCTION  FOUR BASIC STEPS – copy onto handout  Attachment and entrance: Virus chemically recognizes a host cell and attaches to it. Either the whole virus or only its DNA or RNA material enters the cell’s cytoplasm.

VIRUS REPRODUCTION  Synthesis of protein and nucleic acid units: molecular information contained in the viral DNA or RNA directs the host cell in replicating viral components (nucleic acids, enzymes, caspid proteins, and other viral proteins)

VIRUS REPRODUCTION  Assembly of the units: The viral nucleic acids, enzymes, and proteins are brought together and assembled into new virus particles.

VIRUS REPRODUCTION  Release of new virus particles: newly formed virus particles are released from the infected cell and the host cell dies.

TWO REPRODUCTIVE CYCLES Depending on the type of virus, virus reproduction can occur two ways:  Lytic Cycle – host cell bursts  Lysogenic Cycle – virus waits before hijacking cell; cell multiplies

CULTURE LAB  We will be completing a lab in which we culture bacteria from various objects around Adam Scott  Lab due on Tuesday, February 18 th.  This lab will be mostly formal---more info to come.

EXIT CARD What Kingdom does algae belong to? How is it not Plantae (list characteristics)?