Prokaryote Microorganisms

11.0 Classify animals according to type of skeletal structure, method of fertilization and reproduction, body symmetry, body coverings, and locomotion.Examples: skeletal structure - �vertebrates, invertebrates;fertilization- external, �internal;reproduction -sexual, asexual;�body symmetry- bilateral, �radial, asymmetrical;body coverings- feathers, �scales, fur;locomotion- cilia, flagella, �pseudopodia

Prokaryotes: What is a prokaryote?

Lack a nucleus Unicellular

What 2 Kingdoms would include prokaryotes?

What 2 Domains would include prokaryotes?

Recall that under the 5 Kingdom Classification System, ALL prokaryotes were included in one kingdom – Monera.

Eubacteria (Domain Bacteria)

Found almost everywhere

Usually surrounded by a cell wall that protects it and determines its shape.

Cell walls contain peptidoglycan

_________________ surrounds the cytoplasm inside the cell wall.Source:

http://danmarkltd.tripod.com/taxonomy/id6.html

Archaebacteria (Domain: ??)

Lack peptidoglycan in the cell wall Have membrane lipids not found in

other organisms Can be found in extreme

environments DNA sequences of key genes are

more like those of eukaryotes than eubacteria

Identification of Prokaryotes:

1. Shape: a. Bacilli – rod-shapedb. Cocci – sphericalc. Spirilla - spiral and corkscrew-shaped

2. Cell walls – Gram staininga. Violet (primary) stain stains the peptidoglycanb. Alcohol wash will rinse the stain from thin-

membraned organisms (Gram -), but not from thick-walled (Gram +).

c. Red (counterstain) will make Gram - organisms look pink or light red.

3. Movement – no movement, flagella, snakelike movements, or gliding along secreted slime.

Source:http://mrwrightsclass.net/projects/period4/paige_maria_andreas/EUBACTERIA/eubacteria.html

Metabolic Diversity Heterotrophs:

Chemoheterotrophs – use organic (carbon-based) compounds for energy

Photoheterotrophs – use light for energy, but also need organic compounds for carbon

Autotrophs: Photoautotrophs – use _______ to convert ____ and

_____ to ________ and ________. One type of photoautotroph is cyanobacteria,

which contain a bluish pigment and chlorophyll . Chemoautotrophs:

make organic molecules from CO2, but without light

Use energy from chemical reactions occurring around them

Growth & Reproduction

1. Binary fission – a bacterium doubles in size, duplicates its DNA, and divides in half.

2. Conjugation – the exchange of DNA across a hollow bridge formed by intertwined pili.

3. Spore formation – under adverse conditions, some organisms can form a thick internal wall around its DNA until conditions are more favorable.

Summary: some sexual, some asexual methods

Why Are Bacteria Important?

Decomposers Nitrogen fixers for plants Human uses:

Foods and beverages Clean up oil spills Synthesize drugs and chemicals Help us digest foods