the m icrobial w orld

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The M icrobial W orld. Chapter 5. Prokaryotic Metabolism. Autotrophs Heterotrophs. Autotrophs. Some bacteria and archaea make their own organic compounds Primary producers If they do photosynthesis it takes place in on folded membranes in the bacteria cell - PowerPoint PPT Presentation


The Microbial World

The Microbial WorldChapter 5Prokaryotic MetabolismAutotrophsHeterotrophsProkaryotes show an amazing variety of chemical reactions that are involved in the transfer of energy and the manufacture of chemical compounds. The term metabolism remember, refers to all of these chemical reactions that take place in an organism2AutotrophsSome bacteria and archaea make their own organic compounds Primary producers If they do photosynthesis it takes place in on folded membranes in the bacteria cellPhotosynthetic bacteria account for much of the primary production of open oceanOther bacterial autotrophs- chemosynthetic bacteriaRemember that bacteria dont have membrane bound organelles like eukaryotes so they do not have chloroplasts where photosynthesis takes place in eukaryotes

The end products of photosynthesis are similar to the products eukaryotes create however, the biochemistry of bacterial photosyntheisis is different from that of algae and plants. This process varies among groups of bacteria

Chemosynthetic bacteria derive energy not from light but from chemical compounds like hydrogen sulfides remember you can find some of these bacteria near hydorthermal vents3HeterotrophsMost marine bacteria are heterotrophsHeterotrophs obtain energy from organic matter by respirationRespiration in aerobic bacteria and archaea use oxygenIn Anoxic sediments bacteria use anaerobic respiration Anoxic sediements are sediments that are devoid of oxygen. Bacteria will use sulfate as an oxygen substitute. That is why some sediments smell like rotten eggs. 4Nitrogen FixationBottom dwelling and planktonic cyanobacteria carry out nitrogen fixation

Nitrogen fixation N2 NH4 (covert nitrogen to ammonium)

Ammonium is then transferred into NO3- (nitrate) and other N compoundsThese N sources can be used by primary producersNitrogen fixation requires energy which is provided by ATP from Photosynthesis or other reactions5Unicellular Algae Algae very diverse group (mostly aquatic, mostly photosynthetic) Eukaryotic- cells have a nucleus, organellesPhotosynthesis- ChloroplastLack true leaves, stems, roots

Have plant and animal characteristics- Protista

The color of the algae is a result of the pigments and their concentration

Some show animal like characteristics they swim using a flagella. Some carry out photosynthesis, some move and eat food particles, some do both6DiatomsUnicellular but they can be colonial or form groups or chainsIn a shell made of silica frustule (2 halves) The perforations allow dissolved gases and nutrients to enter and exitColoration- carotenoid pigments (few are colorless) Photosynthetic factoriesSome are toxic

The frustule resembles a round or elongated box. The frustule usually has intricate perforations and ornaments such as spines or rib, making diatoms beautiful when seen under a microscope.

They provide food for themselves as well as other life forms

Some planktonic diatoms produce a potent toxin (domoic acid) which accumulates in shellfish and plankton feeding fishes. This toxin can be fatal in humans and fishes and marine mammals7Diatom ReproductionAsexual reproductionAuxospores- resistant stages that eventually give rise to larger cells that display the frustule characteristic of the species **get smaller each division**Favorable conditions- bloomDiatomaceous ooze- dead diatoms sink and form thick deposits of siliceous materialDiatomaceous ooze is a type of siliceous ooze

Fossils of this diatomaceous ooze is known as Diatomaceous earth8

DinoflagellatesLarge group of planktonic unicellular organisms2 flagella, cell wall, platesPhotosynthesize and ingest Reproduction is almost exclusively by cell divisionBioluminescence Toxic

One flagella wraps around the center groove and one trailing free

The plates of dinoflagellates have spines,pores,or other ornaments

Zooxanthellae live in close association with a variety of animals. Animal

Some of these dinoflagellates release toxic substances and seafood collected during red tide periods and may be posionous10Protozoans (animal like protists)Eukaryotic Structure is simpleAnimal likeProtozoans comprise several groups of unrelated originsHeterotrophs and some photosynthesize

Having a single cell is about the only thing that protozoans have in common. Some form colonies.

Protozoans are the most animal like of the protists they are eukayotic and unicellular. They are found everywhere, marine and freshwater as well as inside of organisms (guts of animals) and in sediments11ForaminiferansType of marine protozoanHave a shell (test) made of CaCO3Pseudopodia- extensions of the cytoplasmLive on the bottom either free or attachedShells of bottom forams are important contributors to calcarious materialWhite cliffs of Dover

Forams on the bottom are important contributors to calcarious material on coral reefs and sandy beaches.

Pseudopodia- Protrudes through the pores in the shell and form a network to trap diatoms and other organisms

Many limestone chalk beds around the world like the white cliffs of dover in england are products of foram sediments that were uplifted from the ocean floor

12RadiolariansPlanktonic marine protozoansSecrete shells of glass and other materials Typical shells are spherical with radiating spines Sausage shaped coloniesWhen they die and sink to the bottom they become silicious ooze Resistant to dissolving under pressure

CiliatesProtozoans Lots of hair like extentionsLocomotion and feedingFound all over seaweeds and in bottom sedimentsLive in gills of clams, urchin intestines,skin of fish

FungiEukaryotic and mostly multicellularMolds, yeasts are unicellular They are heterotrophs that lack chloroplasts500 species of marine fungi (most are microscopic)Decompose detritusSome are parasitesSome form symbiotic relationships with algae lichens

Most important decomposers of mangrove leaves and contribute to the recycling of nutrients in mangrove forests

Lichens filament like growths for the fungi provide the support while algae provide the food from photosynthesis. Lichens arefound on land and sea 15Microbial worldProkaryotesBacteria Cyanobacteria (stromatolites)ArchaeaExtremophilesEukaryotesDiatomsDinoflagellatesProtozoans (animal like)ForaminieransRadiolariansFungi

PresentationTable 1 DiatomsTable 2- DinoflagellatesTable 3- ForaminiferansTable 4- RadiolariansTable 5- CiliatesTable 6- FungiPoster RubricImageDefinitionAt least 5 facts Importance to marine environment/role in marine environment

** this will be a graded assignment**

If you finish early complete your sponge reading and question sheet until we start presenting