Agenda April 15• Objective: Investigate the basic structure

and cellular functions of bacteria.

• 1. QUIZ• 2. Homework Review• 3. Bacteria Guided Reading Packet• 4. HOMEWORK

– Bacteria Packet DUE Tomorrow– QUIZ FRIDAY!!! Bacteria and Viruses

CHAPTER 19: Bacteria and Viruses

19-1: Bacteria

• Prokaryotic organisms

• Grouped into two kingdoms– EUBACTERIA and ARCHAEABACTERIA

• Size ranges from 1 to 5 micrometers.

19-1: Bacterial Kingdoms

• ARCHAEABACTERIA– DNA sequences more similar to Eukaryotes– Anaerobic Methanogans produce methane gas

• EUBACTERIA– Live almost anywhere– Single cell membrane or two cell membranes

Identifying Bacteria• 1. Shape• ROD Bacilli• SPHERICAL Cocci• SPIRAL and CORKSCREW Spirilla

Identifying Bacteria• 2. GRAM STAINING – Two Stains used

Primary stain is VIOLET Counterstain is REDGram + bacteria contain Peptidoglycan = VIOLETGram - bacteria contain lipids = RED

• 3. Movement – Flagella, Undulation, Secretions

Identifying Bacteria

• 3. Movement – Flagella or Undulation

4. Obtaining Energy Metabolic Diversity

• Chemoheterotrophs– Take in organic molecules for energy and carbon

• Photoheterotrophs– Use sunlight for energy– Take in organic molecules for carbon

Chemoautotrophs Make carbon compounds from CO2Use energy from chemical reactions

PhotoautotrophsUse sunlight similar to plantsMake carbon compounds from CO2

Releasing Energy• Obligate Aerobes – require oxygen

– Mycobacterium tuberculosis

• Obligate Anaerobes – Do not require oxygen– Oxygen can kill them– Clostridium botulinum

• Facultative Anaerobes – survive with or without oxygen– Esherichia coli

19-2: Viruses

• Particles of nucleic acids, proteins, and sometimes lipids.

• DNA or RNA core surrounded by a protein coat

• Protein coat called a CAPSID– Proteins bind receptors on host cells.– Virus gains access into cell.

- Very specific to cells they infect.

Virus StructuresRecall phages

from Chapter 12.

Which scientists

worked with them?

Describe the

experiment and itsresults.

Viral Infections

• Lytic Cycle • Virus infects cell, makes

copies, and bursts cell releasing new viruses

• Lysogenic Cycle• Viral DNA is copied with

host cell’s DNA• Virus is copied when host

cell copies itself.

Retroviruses• What is a retrovirus?• A virus with RNA as its genetic material.

– Produces DNA from RNA template.

• What is an example of a retrovirus?• HIV Human Immunodeficiency Virus

• What disease does it cause?• AIDS

• How does it affect the human body?• Attacks immune system destroying cells

Are Viruses Living Things?

• Use your Textbooks to answer this question.• Consider the characteristics required to qualify

as being living…

• Viruses are not considered living things.

• Do not meet all 8 characteristics of life• Cannot reproduce independently• No growth/development• Do not use/obtain energy

DiseasesDISEASE BACTERIAL

OR VIRAL EFFECT ON BODY TRANSMISSION

West Nile  V  Fever, Headache, Body Aches

 Mosquito Bite

Tetanus  B  Lockjaw, Joint stiffness, fever, High BP

 Inhalation

AIDS  V Helper T cells destroyed (Immune System) 

 Blood, Body Fluids, Pregnancy

Hepatitis B V  Fatigue, Abdom Pain

Vomiting, Joint Pain Blood, Body Fluids

Common Cold

 V  Sneezing, Sore throat, Headache, Fever

 Contact with objects, Inhalation

Strep Throat B  Fever, Sore throat, cough,

Fatigue Contact with mucus or wounds

Preventing Bacterial Disease• Vaccines and Antibiotics• Louis Pasteur 1881

– Developd vaccine against anthrax

• Alexander Fleming 1928– Discovers penicillin – Non-toxic but stops growth of pathogens

• Jonas Salk 1952– Polio vaccine using a killed virus