Chapter 5- The Microbial World Flashcards
Characteristics: Smallest and structurally simplest true living organism and the oldest forms of life on Earth
Groups: Bacteria and Archaea
Prokaryotes
Photosynthesis
Chemosynthesis
Heterotrophs
Metabolic Diversity of Archaea and Bacteria
Derive energy from light
Photosynthesis
Derive energy from chemical compounds
Chemosynthesis
Derive energy from organic matter by means of respiration
Heterotrophs
Ancient organisms – fossils found that date back 3.8 billion years
Variety of metabolic types
Widely distributed at sea
They can tolerate wide ranges in temperature, salinity, and even desiccation.
Can be found in many areas including near hydrothermal vents and salt flats, two very extreme environments
Archaea
A variety of shapes including spirals, spheres, rods, and rings
Cell wall structure is semi-rigid, but permeable; most with cell wall
Size is normally microscopic, but a few are large.
Wide variety of metabolic types
Very abundant worldwide
Break down dead organic matter forming detritus, minute particles of organic matter that are available as nutrition for other organisms.
Group: Cyanobacteria, Stromatolites
Marine Bacteria
photosynthetic bacteria most important in the marine environment
Cyanobacteria
Phylum for Diatoms
Chrysophyta
Phylum for Dinoflagellate
Dinoflagellata
massive calcareous mounds formed by cyanobacteria
Stromatolites
Important photosynthesizers for cold water
Protists
Phylum Chrysophyta
Division/class, Bacillariophyta
Frustules made of SiO2
The characteristic color due to yellow and brown carotenoid pigments, in addition to chlorophyll a and c.
Asexual and sexual reproduction
Blooms under ice!
Diatomaceous ooze.
Diatoms
Important photosynthesizers for warm water
Protist
Division Dinophyta, or phylum Dinoflagellata
Most species are marine.
Mostly photosynthetic, some can ingest particles.
Each species has a particular shape, reinforced by plates of cellulose.
Two flagella in grooves for motion
Some are bioluminescent
Dinoflagellate
important dinoflagellates that live in a symbiotic relationship with reef corals, some sea anemones, and other organisms; many of these host organisms have little or no growth without zooxanthellae.
Zooxanthellae
Diatoms and dinoflagellates can go through periods of rapid growth known as this.
This is a result of high levels of nutrients in the water. These blooms can be harmful to marine organisms and even humans at times.
Algal Blooms
