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52 Cards in this Set
- Front
- Back
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Where are most prokaryotic cells found? A) Open ocean B) Oceanic subsurface C) Soil D) Terrestrial subsurface |
B) Oceanic subsurface |
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In what form does prokaryotic genome typically present itself? |
circular dsDNA |
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In what form does eukaryotic genome usually present itself? |
linear ssDNA |
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what is the multicelllular organization in prokaryotic cells? |
specialized cells and filaments - Anabaena |
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What are the three cell shapes? |
1. coccus (cocci) 2. bacillus (bacilli) 3. spirillum (spirilli) |
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What is the general diameter range for cells? |
1 to 5 um |
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What are the three extremes for cell size? |
-Nanobacterium -Epulopiscium -Thimargarita |
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Why do prokaryotic cells generally have higher protein content? |
Because they are simpler structures than eukaryotic cells, prokaryotes typically have a high protein content in order to carry out the functions that they need.
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Prokaryotic membranes lack __________ but may contain related compounds (__________) |
i) cholesterol ii) jopanoids |
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What are the cell wall function? (3) |
1. maintenance of shape 2. protection 3. homeostasis |
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What unique polysaccharide do bacterial cell walls contain? |
Peptidoglycan |
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What are peptidoglycan composed of? |
Linear polysaccharide strands consisting of alternating modifies sugars NAG and NAM |
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What two things interfere with the formation of the peptide bridges and therefore a functional cell wall? |
Penicillin and cephalosporin |
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What is the difference between gram negative cells and gram positive cells? |
Gram positive cells have a thick layer of peptidoglycan outside the plasma membrane. Gram negative cells are surrounded by a cell envelope. |
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What does the cell envelope of a Gram negative cell consist of? |
a second membrane that is more resistant to certain antibiotics and may protect from some pathogens, a periplasmic space between the plasma membrane and outer membrane, a tin wall with lesser peptidoglycan within the periplasmic space. |
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Gram positive cells walls contain the polysaccharide ___________________.
Gram negative cells often have _________ associated with the outer membrane. |
teichoic acid
LPS |
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What prokaryotes lack a cell wall? |
Mycoplasnas |
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Archaeal cell walls do not contain ____________, but may contain ___________________. |
Peptidoglycan
Pseudopeptioglycan |
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What is a capsule? |
A gelatinous layer outside the cell wall made of extracellular polysaccharide and protein. It functions in protection and attachment. |
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What are pili and fimbriae? |
Attachment structures composed of protein. |
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What are the three parts of prokaryotic flagellum? |
1. filament - whip like structure composed of flagellin (protein) 2. hook - structure at the base of the filament before the motor, composed of hook protein 3. basal apparatus - molecular motor that rotates the filament driven by proton gradient. |
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What is spirochetes? |
Two or more helical filaments under the outer part of the cell wall |
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Define chemotaxis, phototaxis, and geotaxis. |
Chemotaxis - chemical stimulus Phototaxis - light stimulus Geotaxis - gravitational stimuli |
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What is a genome? |
The genetic information found mainly in the nucleoid region
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Prokaryotes reproduce _________ by __________. |
asexually
binary fission |
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What is sporulation? |
The production of endospores resulting from a lack of nutrition. |
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What are endospores? |
Resting structures with thick walls that are resistant to heat, UV, desiccation, and many hard chemicals |
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Large amounts of genetic variability result from what? |
Mutations and genetic recombination |
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What is mutation? |
Heritable change in the nucleotide sequence of a cell. (crossing over of homologous pairs does not count) |
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What is genetic recombination? |
The combining of DNA from two different sources |
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What is transformation? |
Uptake of naked DNA from the environment |
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What is transduction? |
Genetic material is transferred between prokaryotes by means of a virus. |
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What are the five steps of bacteriophage? |
1. Attachment 2. Penetration 3. Synthesis of nucleic acid and protein 4. Assembly and packaging 5. Release (lysis) |
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What is conjunction? |
Direct transfer or genetic material between two bacterial cells. (bacterial sex) |
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What four categories can prokaryotes be grouped into based on how they receive their carbon and energy? |
Photoautotroph, chemoautotroph, photoheterotroph, chemoheterotroph |
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What are the three types of oxygen metabolisms? |
1. obligate aerobe - need oxygen 2. facultative anaerobe - can live with or without oxygen 3. obligate anaerobe - does not require oxygen. |
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What molecular systemic method is used today to sort prokaryotes? |
We use molecular signature sequences in highly conserved genes and proteins. |
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What is molecular systematics? |
A scientific discipline that uses nucleic acids or other molecules to infer evolutionary relationships between different species. |
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What ribosomes are present in prokaryotes, and eukaryotes, respectively? |
16s rRNA
18s rRNA |
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The original system for classification was based on ______________. |
Phenotypes |
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Archea are also known as... |
...extremophiles. |
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What are the three kind of extremophiles? |
1. Methanogens 2. Extreme Halophiles 3. Extreme Thermophiles |
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What are three characteristics of methanogens? |
- produce methane by reduction of CO2 with H2 - strict anaerobes - used in sewage treatment |
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What are three characteristics of extreme halophiles? |
- some require salt for growth - found in places like the Dead Sea, Great Salt Lake - cells have high intracellular salt concentration |
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What is a characteristic of extreme thermophiles? |
high temperature environments |
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What domain has the most characterized prokaryotes and taxonomist recognize 18+ gorups |
Domain Bacteria |
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What are two ecological impacts of prokaryotes? |
1. Chemical cycling 2. Symbioses |
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What are four examples of chemical cycling? |
1. Carbon cycle 2. Decomposers 3. Fix atmospheric CO2 and N2 4. Transformation of inorganic compounds |
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What are three ways prokaryotes are symbiotic? |
1. mutualism 2. commensalism 3. parasitism |
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How do bacteria cause disease symptoms? |
They disrupt host physiology by invasion and growth in tissues. |
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What are antibiotics? |
Chemical compounds that inhibit of kill other microorganisms. |
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What are five ways we make prokaryotes work for us? |
Microbial products, decomposers, agriculture, industry, recombinant DNA technology, |
