Bacteria vs. Humans
Bacteria are all around you—in the air you breathe, under your feet, on your skin, and even in your body! They may be tiny, but they can still have an impact on your life.
Use what you already know about bacteria to answer these questions.
1. In what ways are bacteria similar to humans?
2. In what ways are bacteria different from humas?
3. How can bacteria be harmful?
Like humans, bacteria are alive, and some can move. Both obtain energy, exchange gases, grow, and reproduce.
Bacteria cause diseases, release poisonous chemicals, and compete with humans for food.
Unlike humans, bacteria are extremely small; some can live in harsher environments and without oxygen; some bacteria use sunlight to produce their own food.
Missed assignmentMissed assignment
• Complete Chapter 19 vocabulary words in your composition notebooks.
• Page 471 (19-1) 15 words
• Page 479 (19-2) 7 words
• Page 485 (19-3) 5 words
Bell Ringer
• Take out your Chapter 18 notes.
• Be prepared to begin class as soon as the bell rings.
Bacteria and VirusesBacteria and Viruses
Bacteria
Bacteria can survive in extreme conditions. Like this volcanic hot springs.
Bacteria
• Prokaryotes - are commonly called bacteria because they are single celled organisms that lack a nucleus.
-Prokaryotes are broken into 2 very different Kingdoms
1. Eubacteria - commonly found everywhere.
2. Archaebacteria - usually found in unlivable environments (hot springs and oxygen free environments).
3 Ways to Identify Prokaryotes
1. Shape (3 types) Bacilli (rod shaped) Spirilla (spiral
corkscrewed)
Cocci (spherical)
2. Cell wall• Material used to make a gram stain
-Crystal Violet solution-Iodine-Alcohol-Safrain solutions
Gram positive (purple) Gram negative (pink)
3. Movement-Flagella -Lash -Snake -Spiral forward
-Slide on a layer of mucus
http://www.strimoo.com/video/14679578/Bacterial-Motility-Vimeo.html
Human Uses of Bacteria
• Make a number of vitamins that the body cannot produce by itself.
• Both benefit from this symbiotic relationship.
How Prokaryotes Obtain Energy and Release
Energy• Heterotroph- take in organic molecule
for both energy and a supply of carbon.• Autotroph-take in sunlight as well as
organic compounds for energy.• Obligate Aerobe - require a constant
supply of oxygen to live• Obligate Anaerobe - they must live in
the absence of oxygen to survive.• Facultative Anaerobe - can live with
or without energy.
Prokaryotic Growth and Development
• Binary fission - a bacteria replicated it DNA and divides in half.• Conjugation - bacteria exchange genetic information by forming a bridge b/t 2 bacteria cells• Spore formation - is when bacteria form a thick internal wall protecting it from unfavorable living conditions
Importance of Bacteria
• Decomposers - break down the nutrients in dead matter• Nitrogen Fixers - Convertsnitrogen gas to ammonia for plant usage.• Helpful to Humans - breaks
down food in the intestines
Tooth decay
Lyme disease
Tetanus
Tuberculosis
Salmonella food poisoning
Pneumonia
Cholera
Streptococcus mutans
Borrelia burgdorferi
Clostridium tetani
Mycobacterium tuberculosis
Salmonella enteritidis
Streptococcus pneumoniae
Vibrio cholerae
Regular dental hygiene
Protection from tick bites
Current tetanus vaccination
Vaccination
Proper food-handling practices
Maintaining good health
Clean water supplies
Disease Pathogen Prevention
Diseases caused by Diseases caused by bacteriabacteria
Anthrax Bubonic plagueTyphus
Diseases caused by Bacteria
1. How does bacteria affect humans?2. Some bacteria damage the cells and
tissues of the infected organism directly by breaking down the cells food
3. Other bacteria release toxins that travel throughout the body interfering with the normal activity of the host
Causes disease in the body.
Controlling Bacteria• Disinfectant
– Chemical solutions that kill pathogenic bacteria
• Used in homes to clean bathrooms, kitchens, and other rooms.
• Antibiotics– Block the growth and reproduction of bacteria.
• Sterilizing by heat– Destroys all bacteria by subjecting them to
great amounts of heat.• Food processing and storage
– Storing in refrigerator– Boiling, frying, or steaming
Intro to Viruses
What is a Virus?• Viruses - are particles of nucleic acid ,
protein, and sometimes lipids• They can only live by infecting living cells• Viruses are composed of DNA or RNA and a
capsid- a virus protein coat.
T4 BacteriophageTobacco Mosaic
Virus Influenza Virus
Head
Tail sheath
DNA
Tail fiber
RNACapsid
Surfaceproteins Membrane
envelope
RNA
Capsidproteins
Figure 19-9
3 Virus Types
Viral Infections• Virus must bind specifically to a
compatible protein coat. -animal viruses only infect animals-plant viruses only infect plants-Some viruses can infect bacteria. When this happen it is called a bacteriophage.
http://cbs5.com/video/[email protected]
•How viruses affect humansHow viruses affect humans-viruses attack and destroy cells in the
body.
Types of Viral Infections• Lytic Infection - a virus enters a cell,
makes copies of itself, and causes the cell to burst.– Because the host cell is lysed and destroyed
• Lysogenic Infection - a virus integrates its DNA of the host cell and the viral genetic information replicates along with the host cell. In the lysogenic cycle, what happens to the
virus DNA?It inserts itself into the bacterial chromosome.
What is the viral DNA called while it is embedded in the bacterial DNA?
A prophage
• Viruses contain RNA as their genetic information
• May remain dormant for varying lengths of time before becoming active
• An example: AIDS
Retroviruses
Oncogenic viruses
Retrovirus
Adenoviruses
Herpes viruses
Poxviruses
DNA
RNA
DNA
DNA
DNA
Cancer
Cancer, AIDS
Respiratory infections
Chickenpox
Smallpox
Type of Virus Nucleic Acid Disease
Diseases caused by VirusesAIDS Common Cold Hepatitis A, B, and C
Influenza Mumps Polio Rabies
Which of these viral diseases are spread by droplet inhalation? Common cold, influenza, smallpox,
chickenpox, measles, and polio.
• What is droplet inhalation?– Droplets of saliva or mucus that spreads
through the air by sneezing and coughing---also by laughing and talking
Diseases caused by Viruses
Useful internet sites
• www.health.yahoo.com
• www.cdc.gov
• www.medicinenet.com
• www.nlm.nih.gov
• Use these and other websites, textbooks, or the school or local library for information.
Research assignment will count as Research assignment will count as TWO test TWO test gradesgrades..
Infectious DiseaseResearch Project
• You will select a specific infectious disease • Be prepared to give an oral presentation.• Grading will be based on neatness, order of the
slides, information given, and your ability to speak about your topic.
Research assignment will count as Research assignment will count as TWO test TWO test gradesgrades..
Presentations will begin February 17, 2011Presentations will begin February 17, 2011
Interest Interest GrabberGrabber
• What is the purpose of these products?– To relieve cold symptoms
• How do they relieve cold symptoms?– Lower fever, relieve aches and
pains, reduce congestion, stop cough, sore throat, etc.
• Is this a sign that you are cured?– No. A cure would have to disable
the virus that causes the cold.
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