EARLY EARTH & PROKARYOTES
-4.5 billion years ago Earth was formed.
-3.5 billion years ago Earliest life found in the fossil record emerged.
-Prokaryotes were the earliest organisms found in sedimentary rocks: stromatolites.
(Layers formed due to the stick
Have no mitochondria and are therefore anaerobic.
Are photosynthetic with chloroplasts.
Are heterotrophic that absorb or engulf their food.
Are mixotrophic both photosynthetic & heterotrophic.
Only reproduce solely asexually, while others are se
Extreme halophiles live in salty habitats (Great Salt Lake and the Dead Sea).
Some species merely tolerate elevated salinity; others require an extremely salty
environment to grow.
Colonies of certain extreme halophiles form a purple-red scum from bacteri
Obligate aerobes require O2 for cellular respiration.
Facultative anaerobes will use O2 if present but can also grow by fermentation in an
Obligate anaerobes are poisoned by O2 and use either fermentation or anaerobic
MODE OF NUTRITION
Organisms can be categorized by their nutrition, based on how they obtain energy and
carbon to build the organic molecules that make up their cells.
Nutritional diversity is greater among prokaryotes than among all eukaryote capable of
Plasmids replicate independently of the chromosome and can be transferred between
partners during conjugation.
Although the general processes for DNA replication and translation of mRNA into
proteins are fundamentally alike in eukaryotes and prokaryotes,
Many antibiotics, including penicillin, inhibit the synthesis of cross-links in
peptidoglycans, preventing the formation of a functional wall, especially in gram-positive
These drugs cripple many species of bacteria, without affecting human and o
Some prokaryotes decompose dead organisms, returning nutrients to the soil which plants
Prokaryotes are classified into two domains, Bacteria and Archaea, which differ in
structure, physiology and biochemistry.
Most prokaryotes are unicellular.
Clay is important in polymerization because the monomers could bind to charged sites on
Functioned as lattice that brought monomers together, and metal atoms (Zn & Fe)
functioned as catalysts joining them into polymers.
Alternative to clay
Have straw-like projections on their flagella
Includes diatom with their glass-like walls made of SiO2 (silica)
Many have oil in them for buoyancy.
Have two parts (like the shoe box and its lid).
Water molds: fungus-like protist; grow as cot