Aim: How do pathogens infect plants and animals?

5.2b Viruses, bacteria, fungi and other parasites may infect plants and animals and interfere with normal life functions.

HW#20

Text read pages 473,477 to 481

read pages 482 – 487

Answer ques. 1 – 16 page 491

Bacteria are found everywhere…

• Microbiologists broadly classify bacteria according to their shape: spherical, rod-shaped, and spiral-shaped.

• Cocci• Bacilli• Spirilla

Beneficial bacteria are found in living things..

Beneficial Intestinal Bacteria

Some benefits of PROBIOTICS•augments the immune system •alleviates anxiety •prevents arterial disease, lowering cholesterol •prevents and controls diarrhea •inhibits food pathogens and enhances food preservation •inhibits tumors and carcinogenesis •fights fungal/yeast/candida infections •promotes/aids liver function and detoxification •produces natural antibiotic-like agents that fight and

prevent bacterial infections •prevents osteoporosis and promotes longevity

Beneficial bacteria are found in soil..

Beneficial bacteria are used to make food.

Yogurt Cheese

Streptococcus thermophilus and Lactobacillus bulgaricus

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

Maintaining good health

Clean water supplies

Disease Pathogen Prevention

Section 19-2

Common Diseases Caused by Bacteria

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Disease causing Bacteria

Bacteria can be controlled by antibiotics

• Antibiotics, also known as antimicrobial drugs, are drugs that fight infections caused by bacteria. After their discovery in the 1940's they transformed medical care and dramatically reduced illness and death from infectious diseases. However, over the decades the bacteria that antibiotics control have developed resistance to these drugs. Today, virtually all important bacterial infections in the United States and throughout the world are becoming resistant. For this reason, antibiotic resistance is among CDC's top concerns.

Differences between viruses and bacteria

Virus• 0.01 to 0.3 micron

• envelope called a protein coat and a core of genetic material, either DNA or RNA

• invade other cells and hijack their cellular machinery to reproduce

Bacteria•0.3 to 2.0 micron

•rigid cell wall and a thin, rubbery cell membrane surrounding the fluid, or cytoplasm (organelles)

•reproduce themselves

What is a virus and are they living or non-living?

• Ebola Virus • Chicken Pox Virus

T4 BacteriophageTobacco Mosaic

Virus Influenza Virus

Head

Tail sheath

DNA

Tail fiber

RNACapsid

Surfaceproteins Membrane

envelope

RNA

Capsidproteins

Section 19-3

Figure 19-13 Virus Structures

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Viruses come in a variety of sizes and shapes. It is composed of a core of DNA or RNA, surrounded by a

protein coat.

HIV Virus

Human Immunodeficiency Virus

Onion cell

Bacteriophage enzyme lyses the bacterium’s cell wall, releasing new bacteriophage particles that can attack other cells.

Bacteriophage proteins and nucleic acids assemble into complete bacteriophage particles

Bacteriophage takes over bacterium’s metabolism, causing synthesis of new bacteriophage proteins and nucleic acids

Bacteriophage injects DNA into bacterium

Bacteriophage attaches to bacterium’s cell wall

Bacteriophage

DNA

protein

Bacteriophage protein coat

Bacteriophage DNA

Bacterialchromosome

Lytic Cycle of a Virus

Section 19-3

Figure 19-14 The Lytic Cycle

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Fill in the Life Cycle of a Virus