Chapter 26: Bacteria and Archaea

Prokaryotes

Unicellular, small/simple, no nucleus/organelles, 1 chromosome, reproduces by binary fission, high metabolic diversity, and thrives in extreme environments.

Eukaryotes

unicellular, large/complex, has nucleus/organelles, multiple chromosomes, mitosis/meiosis reproduction, low metabolic diversity.

Bacteria

1 type of RNA (5 subunits), peptidoglycan in cell wall, formylmethionine, no histones.

Archaea

1 type of RNA (13 subunits), no peptidoglycan in cell wall, methionine, histones present.

Germ Theory

Many diseases are caused by the presence/actions of microorganisms within the body.

Koch's Postulates

Criteria used to identify causative agents of a particular disease.

1.) microorganism/pathogen must be present

2.) pathogen can be grown in pure culture

3.) pathogen from pure culture can cause disease in healthy subject

4.) process can be repeated in new host

Ways Infectious Diseases Spread

1.) Passed from person to person

2.) Bitten by insect/animal

3.) Ingesting contaminated food/water, exposure to microbes

Virulence

Ability to cause disease (heritable/variable)

Endospores

Tough, thick-walled, dormant structures, formed in environmental stress

Antibiotics

Molecules that kill bacteria or stop them from growing, produced naturally by soil bacteria and fungi

Bioremediation

Use of bacteria and archaea to clean up sites polluted with organic solvents.

Lateral Gene Transfer

Allows for acquisition of new genetic variation (not available via binary fission)

Transformation

Bacteria/archaea naturally take up DNA from the environment released by cell lysis or secreted.

Transduction

Viruses pick up DNA from one prokaryotic cell and transfer it to another.

Conjugation

Genetic info transferred by direct cell-to-cell contact.

Morphological Diversity of Prokaryotes

size (1um), shape (filaments, spheres, rods, chains, spirals), motility (flagellum)

Gram-Stain

dyeing to examine cell walls

Gram-Positive Cells

Purple, extensive, carbohydrate peptidoglycan

Gram-Negative Cells

Pink, thin layer of peptidoglycan, and outer layer of phospholipid

Autotrophs

Food is self synthesized from simple molecules

Heterotrophs

Food is from molecules produced by other organisms

Phototrophs

From sunlight

Chemoorganotrophs

From organic molecules

Chemolithotrophs

From inorganic molecules

ATP (adenosine triphosphate)

source of energy for use and storage at the cellular level

ETC (electron transport chain)

series of protein complexes and organic molecules facilitating transfer of electrons

ATP synthase

enzyme within mitochondria of animal cells that produce ATP

Eukaryotic Cellular Respiration

occurring within mitochondria the final electron receptor is oxygen and its byproducts are C02 and H20

Prokaryotic Cellular Respiration

occurs within the cytoplasm.within cell membrane along with ATP generation

Fermentation

prokaryotes making ATP without ETC

Photophosphorylation

process of utilizing light energy from photosynthesis to convert ADP to ATP.

Oxygen Revolution

period when photosynthetic organisms (like cyanobacteria) dramatically increased Earth's oxygen levels.

The Nitrogen Cycle

drives the movement of nitrogen atoms through ecosystems around the globe as caused by widespread use of NH3 fertilizers causing nitrate pollution in aquatic environments.

Nitrite

less stable, used in food preservation, forms nitrous oxide (when oxidized forms nitrate)

Nitrate

stable/inert, used in fertilizers/explosives, forms nitric acid

Actinobacteria

Bacteria located in soil/freshwater habitats, decomposers, causes tuberculosis and leprosy, and produces hundreds of antibiotics.

Firmicutes

Bacteria located in the human gut and animal intestines, aids digestion.

Spirochaetes

Bacteria located in the guts of animals as pathogens, parasitic organisms causing lyme disease and syphilis, has a cork-skrew shape, and produces ATP via fermentation.

Euryarchaeota

Archaea that has many diverse habitats.