Bacteria & Viruses
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Transcript of Bacteria & Viruses
Bacteria & Viruses
Chapter 19
Bacteria Microscopic life covers nearly every square
centimeter of Earth. All bacteria are prokaryotes. Classifying Prokaryotes
Prokaryotes are identified by their size, shape, the way they move, the way they obtain energy.
Prokaryotes are placed into two kingdoms▪ Eubacteria: Larger of the two kingdoms, very diverse,
live everywhere.▪ Typical eubacteria lives in the human intestines (ex. E.Coli)
▪ Archaebacteria: Similar to eukaryotes, live in harsh environments.
Identifying Prokaryotes Shape: Three different shapes
Bacilli- Rod shaped Cocci- Spherical shaped Spirilla- Spiral/corkscrew shaped
Cell Wall: Two different types of cell walls Thin walls- Peptidoglycan layers Thick walls-Lipid layers Gram Staining: Methods used to identify wall type▪ Gram Positive: Identifies thicker, walls stain turns dark
violet.▪ Gram Negative: Identifies thinner, walls stain turns pink or
light red.
Identifying Prokaryotes Cont…
Movement: If they move & how they move. Propelled by flagella (whip-like structure). Lash, snake, or spiral forward.
Metabolism: The way the organism obtains and uses energy. Heterotroph- Those that can not make their own food.▪ Chemoheterotrophs: Takes in organic material for food & carbon▪ Photoheterotrophs: Carry out photosynthesis and in take organic
material for carbon. Autotroph- Those that are capable of making their own
food.▪ Photoautotrophs: Use light to convert CO2 and H2O into carbon
compounds.▪ Chemoautotrophs: Do not need light to convert CO2 and H2O in
carbon compounds.
Energy
Obligate aerobes: Require oxygen to live
Obligate anaerobes: Can not live in the presence of oxygen, in fact in some cases oxygen can kill these organisms.
Facultative anaerobes: Can function in different ways depending on their environment.
Growth & Reproduction of Prokaryotes
Bacteria can reproduce at astonishing rates, some reproduce every 20 minutes.
Types of Reproduction: Binary Fission-Prokaryotes copies DNA, divides in
half and produces two identical cells (asexual). Conjugation-Two prokaryotic cells exchange
genetic material to reproduce (sexual). Spore Formation- When conditions are right
prokaryotes can produce spores which can later when conditions are right will germinate and become bacteria.
Importance of Bacteria Decomposer
Breaking down of dead or decaying organisms. Nitrogen Fixer
Converts nitrogen gas into a form that can be usable by plants.
Human Uses Industry Technology Synthesizing vitamins Genetic Engineering Oil Spills
Viruses Viruses are particles of nucleic acid,
protein, and in some cases lipids. Typically viruses have a D.N.A. core and
a protein coat▪ Capsid: The protein coat of the virus
Viral Infection
Lytic Infection: A virus enters a cell , makes copies of itself and then causes the cell to bust and release the copies it made of the virus.
Lysogenic Infection: A virus integrates its D.N.A. into the D.N.A. of the host cell, and the viral genetic information replicates along with the host cell’s D.N.A.
Viral Infection
Viruses
Retroviruses: A virus that infects a cell and then uses it’s R.N.A. to make copies of it’s D.N.A. and then that D.N.A. is inserted into the host cells D.N.A. Called retro because it goes from
R.N.A.D.N.A. the opposite of other viruses. Can lay dormant in the host cell for long
period of time. Some cancers are cause by retroviruses as
well as H.I.V. the virus that causes A.I.D.S.
Diseases Caused by BacteriaBacteria in Humans:
Some bacteria infect the body then damage tissues and cells by breaking them down for food
Some Bacteria release toxins that interfere with normal cell activities.
We use Vaccines & Antibiotics to prevent and or treat bacterial infections.
Bacteria in Animals: Many bacteria can affect both humans and
animals.
Diseases Caused by Bacteria
Diseases Caused by BacteriaDisease Bacterium Effect
Lyme Disease Borrelia burgdorferi Fever, Fatigue, AchesTetanus Clostridium tetani Muscle Spasms, DeathTuberculosis Mycobacterium
tuberculosisFatigue, Fever, Night Sweats,
Diphtheria Corynebacterium dihtheria
Fever, Sore Throat
Bacterial Meningitis
Neisseria meningitidis High Fever, Nausea, Fatigue
Strep Throat Streptococcus pyogenes
Sore Throat, Fever, Swollen Glands
Tooth Decay Streptococcus mutans Decay of Tooth Enamel
Controlling Bacteria
There are many ways to control bacterial growth Sterilization- Killing bacteria using heat Disinfectants- Killing bacteria using
chemicals Food Processing
Diseases Caused by Viruses Viral Disease in Humans:
Viruses disrupt the human body’s equilibrium Many viruses infect and kill cells Can’t be treated with antibiotics but can be
vaccinated for. (some viruses eliminated by vaccines)
Viral Disease in Plants & Animals: Viruses infect plants & animals very similarly to
the way they infect humans, but in many cases carry be more severe and even can cause cancer.
Diseases Caused by Viruses
Diseases Caused by VirusesDisease Effect Transmission
Common Cold
Sneezing, Sore Throat, Headache Inhalation
Influenza Fever, Sore Throat, Nasal Congestion
Contact or Inhalation
Smallpox Fever, Fatigue, Back Ache, Rash Contact or Inhalation
Warts Skin Growths Contact with wartAIDS Immune System Destroyed Contact w/bodily
fluidChickenpox Fever, Itchy Rash, weakness Contact w/rashMeasles Fever, Rash, White Spots, Cough, InhalationHepatitis A Jaundice, Nausea, Fatigue,
Stomach PainHuman Waste
Hepatitis B Diarrhea, Nausea, Fatigue, Joint Pain
Contact w/bodily fluid
Hepatitis C Jaundice, Nausea, Fatigue, Stomach Pain
Contact w/bodily fluid
West Nile Fever, Fatigue, Body ache Mosquito bitePolio Fever, Muscle weakness,
headacheInhalation