The Microbial World Chapter 5 TmHlcMDIOQ

Microorganisms All three domains have microogranism representation What are those three domains? Without microorganisms there would be no life on earth.

Domain: Bacteria

Domain: Archaea

Domain: Eukaryota

Primary producers Microorganisms are the most important primary producers Directly or indirectly feed most marine animals

Prokaryotes Small Structurally simple Oldest life forms on earth – Carry out nearly all the chemical processes more complex organisms do Some unique processes to prokaryotes Most chemical processes evolved first in prokaryotes

Prokaryote Structure Cell wall Lack a nucleus Lack membrane bound organelles Differ from Eukaryotes in – Shape of DNA – circular shape – Size of ribosomes

Prokaryote

Two Prokaryotic Domains Bacteria Archaea Even these two prokaryotic domains have important differences Bacteria and Archaea are as different from each other as they are from humans! Woah! Discovery ed

Bacteria Structurally simple Classified as prokaryotes Evolved a range of metabolic abilities Abundant in all parts of the ocean Shapes – Spheres, rods, sprials, rings -Ridged cell wall with slimy covering (attach to surfaces)

Size of bacteria Smaller than unicellular eukaryotes. Exception- bacteria found in sediment off southwest Africa- large enough to be seen with the naked eye

Where do they live Can grow to extremely high numbers in favorable conditions – Detritus (particles of dead organic matter) Decay bacteria – break down waste products and dead organic matter – Releases nutrients into the environment

Why are they important As we know bacteria are very abundant – Marine environment offers some new discoveries Make up large part of the organic material that feeds bottom-dwellers Important in dredging oil and other toxic pollutants Bad side- spoil fish and shellfish catches

d1mk d1mk

Cyanobacteria Blue-green algae Photosynthetic – Pigments chlorophyll – Phycocyanin (Blue) – Phycoerythrin (Red) Visible color depends on the relative amounts of the two pigments

Cyanobacteria Where among the first photosynthetic organisms on earth. – Accumulation of oxygen in our atmosphere Stromatolites- Massive calcareous mounds formed by cyanobacteria. – Date back to 3 million years –

Cyanobacteria Endolithic- burrow into calcareous rocks and coral skeletons Red tides- caused by a planktonic form that blooms – Some can cause skin rashes on divers and swimmers Epiphytes- on algae and plants Endophytes- live inside algae

Bathroom Break

Archaea Some times called archaebacteria Simple Primitive life Important role in the early evolution of life

Structure Small Spherical, spiral, rod shaped Despite being prokaryotic, there is evidence that archaea are more closely related to eukaryotes than bacteria

Where do they live? Some groups were discovered recently Extreme environments – Hot sulfur springs, saline lakes, highly acidic or alkaline environments – Extremophiles “lovers of extreme environments” Also found in extreme marine environments They are not restricted to extreme environments – Common in the water column and other marine environments –

Exit Ticket 1)Blue green algae are known as a) Archaea b) Extremophiles c) Cyanobacteria d) Cilliates 2) Which of the following is not a domain a) Archaea b) Bacteria c) Eukaryota d) Fungi 3) Bacteria and Archaea are very closely related a) True b) False 4) Stramenopiles are made up of a)Cyanobacteria b) Diatoms c) Dinoflagellates d) Amebas 5) Bacteria are prokaryotes a) True b) False