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| An organism of the kingdom Monera comprising the bacteria and cyanobacteria, characterized by the absence of a distinct, membrane-bound nucleus or membrane-bound organelles, and by DNA that is not organized into chromosomes. |
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| One of two prokaryotic domains of life, the other being Archaea. |
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| One of two prokaryotic domains of life, the other being Bacteria. |
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| An organism that obtains energy from sunlight and carbon from CO2 by photosynthesis. |
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| An organism that cannot make it won organic food molecules and must obtain them by consuming other organisms or their organic products; a consumer or decomposer in a food chain. |
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| An agent such as a virus, bacteria, or fungus, that causes diseases. |
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Thermophile: A microorganism that thrives in a hot environment (often 60-80 degrees C).
halophile: A microorganism that lives in a highly saline environment, such as the Great Salt Lake or the Dead Sea. |
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| chemoautotroph & chemosynthesis |
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chemoautotroph: An organism that obtains both energy and carbon from inorganic chemicals. A chemoautotroph makes its own organic compounds from CO2 without using light energy.
chemosynthesis: |
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| Prokaryotes and fungi that secrete enzymes that digest nutrients from organic material and convert them into inorganic forms. |
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Endotoxin: A poisonous component of the outer membrane of gramnegative bacteria that is released only when the bacteria die.
Exotoxin: A poisonous protein secreted by certain bacteria. |
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| A process by which the mitochondria and chloroplasts of eukaryotic cells probably evolved from symbiotic associations between small prokaryotic cells living inside larger cells. |
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| Kingdom Protista. Most protists are unicellular, though some are colonial or multicellular. |
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| Protist that produces its food by photosythesis |
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| Any of a large group of single-celled, usually microscopic, eukaryotic organisms, such as amoebas, ciliates, flagellates, and sporozoans. |
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| Algae and photosynthetic bacteria that drift passively in aquatic environments |
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| a usually nonphotosynthetic free-living protozoan with whiplike appendages; some are pathogens of humans and other animals |
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| Protist that moves and feed by means of pseudopodia |
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| The ciliates are a group of protozoans characterized by the presence of hair-like organelles called cilia, which are identical in structure to flagella but typically shorter and present in much larger numbers with a different undulating pattern than flagella. Cilia occur in all members of the group (although the peculiar suctoria only have them for part of the life-cycle) and are variously used in swimming, crawling, attachment, feeding, and sensation. |
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Dinoflagellate: A member of a group of protists belonging to the alveolate clade. Dinoflagellates are common components of marine and freshwater phytoplankton.
Diatoms: A unicellular, autotrophic protist that belongs to the stramenopile clade. Diatoms possess a unique, glassy cell wall containing silica. |
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| Compare and contrast archaea and bacteria. |
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Both archaea and bacteria are single-celled, and they are both prokaryotes, so they do not have a nucleus or organelles.
There is a difference in cell membranes. The phospholipids in Archaea have ether bonds, while Bacteria have ester bonds. In addition, the glycerol group in Archaea is different from any other life form, and the lipid tails are chemically different from other organisms as well. Most archaeal cell walls do not contain peptidoglycan (in contrast to bacteria). The genes and enzymes that are found in Archaea resemble more those found in Eukaryotes than in Bacteria.
Also, Domain Bacteria cannot survive in environments above 100 degrees C, while Domain Archaea can live in extreme temperatures. |
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Explain what a pathogenic bacteria is and explain the source and trouble with endotoxins and exotoxins. |
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Pathogenic bacteria are bacteria that cause infectious disease. Most often, our body's defenses prevent pathogens from affecting us, but sometimes a pathogen establishes itself in the body and causes illness.
Exotoxins are proteins secreted by bacterial cells and include some of the most powerful poisons known. OCcasionally, species can acquire an exotoxin-producing gene through transfer from another species, such as contaminated ground beef and fresh produce.
Endotoxins are components of the outer membrane of the gram-negative bacteria that are released when the cell dies.Exotoxins are generally heat labile, and are protein in nature. Many can be detoxified with retention of antigenicity by treatment with formaldehyde (toxoid). Many are important virulence factors in pathogenic bacteria. |
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| Explain the endosymbiotic theory and how it relates to prokaryotes and eukaryotes today. |
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Proposes that these organelles were once prokaryotic cells, living inside larger host cells. The prokaryotes may initially have been parasites or even an intended meal for the larger cell, somehow escaping digestion.Because virtually all eukaryotes have some sort of mitochondria, while only photosynthetic eukaryotes have chloroplasts, it has been proposed that endosymbiosis occurred twice, in series. First, an aerobic (oxygen-using) heterotrophic prokaryote was taken in by a larger host cell. In time, the prokaryote co-evolved with the host, eventually becoming something like a mitochondrion. Next, a photosynthetic prokaryote was taken in by a mitochondrion-containing cell.
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