Chapter 19 NotesKingdoms Archaebacteria

andEubacteria

All bacteria are Prokaryotic.

This means that they are organisms that

are one-celled and do not contain a

nucleus or other membrane bound

organelles.

Their sizes range between 1-5

micrometers. 1 micrometer = 3.93700787 × 10-5 inches

All bacteria were once placed into the Kingdom Monera, but now are now

divided into:Kingdom Eubacteria

• Cell walls contain a carbohydrate called peptidoglycan

• Cell membrane lipids differ from Archaebacteria

• DNA unlike eukaryote

Kingdom Archaebacteria

• Cell walls do not contain a carbohydrate called peptidoglycan

• Cell membrane lipids differ from Eubacteria

• DNA similar to eukaryote DNA

Archaebacteria are ancient bacteria. They were the first organisms to

appear on Earth.

The three major types of Archaebacteriaare:

Methanogens -(methane-producers) responsible for the production of

methane, or Swamp gas, can be found:

Halophiles – are salt tolerant and live in saturated brine and salted areas.

Thermophiles – are heat tolerant and live in hot Springs and Black smokers (where hot gases are released into the bottom of the ocean).

Kingdom Eubacteria contains more evolved bacteria.

Some examples of Eubacteria are:

• Nitrogen Fixing Bacteria

• Cyanobacteria

• Bacteria involved in Decomposition

• Bacteria involved in Food ProcessingAnd

Bacteria that cause disease.

Nitrogen Fixing-fixing bacteria convert nitrogen gas into a form of nitrogen that can be used by plants. They

are essential to the ecosystem and its food webs.

CyanobacteriaCyanobacteria, originally called blue-green bacteria or blue-green algae, produce 20 – 30% of the oxygen here on Earth.

Pseudomonas is one kind of bacteria found in the soil. Bacteria recycle dead plants and animals by turning them into minerals and nutrients that plants can use. This is called decomposing.

http://www.earth-cards.com/pseudomonas_bacteria.htm

Shapes of Bacteria • Meningitis

• Strep throatCoccus

(sphere)

• Anthrax• Botulism

Bacillus (rod)

• Whooping Cough• SyphilisSpirillum

(spiral)

Bacteria are classified based on a number of characteristics. One of these characteristics is their shape.

Gram Staining (another method for distinguishing between types of bacteria)is determined by the

composition of the bacterial cell wall.

• Gram Positive (peptidoglycan)

• Gram Negative (no peptidoglycan)

Bacteria can also be grouped into categories based on how they obtain

their nutrition.

Autotrophs can produce their own food given an outside energy source.

Chemoautotrophs use energy from chemical reactions in their environment to produce their

own food.

Bacteria from a Black Smoker Black Smoker

Photoautotrophs use sunlight as an energy source to convert simple compounds into

complex compounds used for food.

Heterotrophs must obtain food from their environment. They do this by either

Ingestion: an anemone

feedingAbsorption: a fungus absorbing nutrients

Bacteria can also be sorted based on their method of converting “food” into energy.

Bacteria can also be identified based on their methods of releasing energy.

All living things require energy. They must break down food to obtain it. This is done in different manners

depending on the organism and the presence of oxygen in the

environment.

Aerobic Cellular Respiration requires oxygen (releases more

energy, ATP)

Facultative Anaerobes switch between cellular respiration

and fermentation depending on the presence of oxygen in their

environment

Anaerobic Cellular Respiration (also called fermentation) does not require oxygen and releases

less energy.

Releasing Energy

Bacteria can reproduce asexually by binary fission or sexually by

conjugation.

Rate of Bacterial Growth over Time

Phases of the Bacterial Growth Curve

• a. Lag phase - bacteria adjust to their environment

• b. Exponential growth phase - bacterial increase rapidly in number (binary fission)

• c. Stationary phase - bacteria reproduce at the same rate as cells die

• d. Death phase - bacteria die as their environment is contaminated and/or their food is used up.

Spore Formation

• Under unfavorable conditions, spores (vegetative reproductive structures) can form. These structures are resistant to harsh conditions, such as heat, cold, and drought and can survive for years. Given good conditions, they grow.

• Endospores are composed of a thick internal wall that encloses DNA and some cytoplasm.