ProkaryotesHonors Biology

Monkemeier

Microfossils are fossilized forms of microscopic life.

The oldest microfossils are approximately 3.5 billion years old.

The microfossils resemble modern day Archeabacteria.

Modern Archeabacteria live in extreme conditions and early Earth was harsh and was extreme.

In addition to microfossils, indirect evidence for ancient life can be found in the form of sedimentary deposits called stromatolites.

Stromatolites provide evidence that photosynthetic bacteria were on the Earth approximately 2.5 billion years ago.

The cyanobacteria are also known as blue-green algae.

Prokaryotes are divided into two Domains, the ARCHAEA and the BACTERIA.

ALL cells whether prokaryotic or eukaryotic share three features:Plasma membrane: a cell membrane that

acts as a barrier to the exterior environment.Centrally located genetic material known

as DNA. In prokaryotes the DNA is a single, circular structure. In eukaryotes, the DNA has associated proteins, is linear and occur in even numbers.

Cytoplasm: The area between the plasma membrane and fills the interior of the cell. It has a jello-like consistency and can move. The liquid portion minus the organelles is the cytosol.

Some prokaryotes move by rotating flagella.

Flagella are long, threadlike structures protruding from the surface of the cell that are used in locomotion.

Bacteria can swim at speeds of up to 70 cell lengths per second by rotating their flagella like screws.

The rotary motor uses the energy stored in a gradient that transfers protons across the plasma membrane to power the movement of the flagellum.

ARCHAEA Amino acid that

initiates synthesis: methionine

Cell wall: not composed of peptidoglycan

Cell membrane: Monolipid bilayer

Noncoding regions known as introns in the genes

BACTERIA Amino acid that

initiates synthesis formyl-methionine

Cell Wall consists of peptidoglycan

Cell membrane is a phospholipid bilayer

Genes do not contain noncoding regions.

Archaea bacteria are found in extreme conditions. Early Earth was hostile and extreme. Methanogens, Halophiles, Thermophiles, acidophiles.

Archaea are anaerobic: Bacteria are found in water, soil and air.

Bacteria come in three basic shapes.

Bacteria have a simple cell structure. Bacteria can be classified by their

ShapeIf they contain or do not contain

flagellaIf they have flagella, the number

and positions of the flagella.Reaction to Gram Staining

Technique