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/?id=20238@kpix.dayport.com

•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.