CH 11 Prokaryotes

Coccus

Spherical

Bacilli

Rods

Sprilla

Stiff spiral

Spirochetes

flexible spirals

Vibrio

Curved Rods

Coccobacillius

Spherical Rods

Pleomorphic

varied shape and size

• star, rectangle, etc

Binary Fission

• Asexual reproduction (only one parent is required)

• Produces two genetically identical daughter cells (except for occasional mutations)

• Fast and efficient

• Allows bacteria to reproduce rapidly under favorable conditions

NOT MITOSIS OR MEIOSIS

Prokaryotes Reproduction

• Binary fission

  • snapping division

• Budding

• Spore Formation

Snapping Divison

Gram positive bacteria only

• Parent cell outer cell membrane tears due to increased tension

• Daughter cell remains hanging onto parent cell via small remnant of the outer wall

Spore Formation

Reproductive cells of actinomycetes and fungi

• Each contain genetic information and develop a clone of the original organism

Budding

Prokaryotes and yeast

• Outgrowth of the original cell (bud) receives a copy of DNA and enlarges it

• The bud is later cut off from the parent

Diplococci

Cocci that reminds attached in pairs

Streptococci

Long chains of cocci

Tetrads

Cocci that divide in perpendicular planes and remain attached

• 4 cocci

Sarcina

A cubodial packet of cocci

Staphylococci

a cluster of cocci

• grape formation

Palisade

A folded arrangement of bacilli

Bergey’s Manual of Systematic Bacteriology

the standard reference used to identify and classify bacteria according to their evolutionary (phylogenetic) relationships and characteristics.

• Identify unknown bacteria by comparing their characteristics.

• Classify bacteria into groups based on genetic, biochemical, physiological, and structural features.

• Assign scientific names using standardized nomenclature.

• Show evolutionary relationships among bacteria using molecular evidence, especially 16S rRNA gene sequencing.

Archaea

• Lack peptidoglycan

• Cytoplasmic membrane lipids have branched or ring-form hydrocarbon chains, whereas bacterial membrane lipids have straight chains.

• Initial amino acid in their polypeptide chains, coded by the AUG start codon, is methionine

• Do NOT cause disease

• Reproduce by binary fission, budding, and fragmentation

Extremophiles (archaea)

Microbes that require extreme conditions of temperature, pH, or salinity to survive

Thermophile

microorganisms requiring temperatures above 45°C.

• Live in hot springs

Halophile (archaea)

Microorganisms requiring high salinity environments (>9% NaCl)

• Dead sea, great salt lakes

Methanogen (archaea)

Obligate anaerobes that convert CO2H2 & organic acids into methane

• play significant roles in the environment by converting organic wastes in pond, lake, and ocean sediments into methane.

• Other methanogens living in the colons of animals are one of the primary sources of environmental methane