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| Review: give the basic characteristics of prokaryotes. | no nucleus; no membrane enclosing DNA cells; lack organelles; no cellulose in cell walls; single chromosome; no streaming in cytoplasm; cell division without mitosis; flagella used for locomotion (some glide); have smaller ribosomes (site of protein synthesis); simple cytoskeleton. |
| What invention changed the world of science? | Hooke and van Leeuwenhoek invented the light microscope. |
| What 2 kingdomes compose the classification prokaryotes? | Eubacteria and Archaebacteria |
| What accounts for the difference in size between bacteria and eukaryotes? | Eukaryotic cells contain much more complex ranges of membrane-enclosed organelles. |
| Compare the size of bacteria and eukaryotes. | Bacteria range from 1-10 micrometers; eukaryotes range from 10-100 micrometers. |
| How large is 1 micrometer? | It's 1/1,000,000 of a meter, so bacteria are small! |
| Give the basic structure of eubacteria. | In general: surrounded by cell wall; composed of complex carbohydrates to protect from injury; cytoplasm surrounded by cell membrane (inside cell wall); some eubacteria have 2 cell membranes (resistent to damage); move using flagella. |
| How many phyla exist in the eubacteria kingdom? | Biologists do not agree on this, as there are so many different lifestyles among eubacteria. |
| Cyanobacteria are photosynthetic; what does this mean? | They use sunlight energy to make their own food. |
| What color(s) are cyanobacteria? | Most are blue-green, but they can be yellow, brown, red. |
| Compare the photosynthetic pigments in cyanobacteria to chloroplasts. | Chloroplasts are more complex and are found in plants. |
| Where are cyanobacteria found? | Throughout the world: fresh & salt water; hot water; Arctic; snow; growing after volcanic eruptions. |
| What are the newest group of eubacteria that have been discovered, and how are they different from other bacteria? | Prochlorobacteria or Prochlorophyta. They contain chlorophyll a and b, making them more similar to chloroplasts of green plants than to cyanobacteria. |
| What characteristics separate Archaebacteria from the Eubacteria kingdom? | Archaebacteria lack an important carbohydrate found in the cell walls in eubacteria; different types of lipids in cell membranes; different types of ribosomes; different gene sequences; live in different environments. |
| What are methanogens? | Archaebacteria that live in oxygen-free environments and produce methane gas. |
| In what shapes can bacteria be found? | They are: in rods (bacilli), spheres (cocci), or spirals (spirilla). |
| What are some forms in which bacteria arrange themselves? | Some in colonies; some in long chains; some in clusters, or large clumps. |
| Who was Hans Christian Gram? | He invented Gram staining. |
| What are Gram-positive bacteria? | If only one thick layer of carbohydrate and protein molecules outside the cell membrane took up the crystal violet stain (purple). |
| What are Gram-negative bacteria? | Bacterial cells with a second outer layer of lipid and carbohydrate molecules take the safranine (red stain). |
| How do bacteria move? | Some move with flagella; some lash, snake, spiral forward; some glide slowly; some do not move at all. |
| What term is used to describe photosynthetic eubacteria? | phototrophic autotrophs (they trap energy from sunlight). |
| What is unique about chemotrophic autotrophs? | They obtain their energy by taking in organic molecules and then breaking them down and absorbing them. |
| What is Salmonella and what does it do? | Salmonella is a bacteria growing in foods such as raw meat, poultry, & eggs. In food, poisons are released, causing serious illness in humans who eat the food. |
| What does respiration do? | Respiration = process involving oxygen and breaks down food molecules to release energy. |
| How does fermentation help cells? | Fermentation enables cells to carry out energy production without oxygen. |
| What are obligate aerobes? | These are organisms that require a constant supply of oxygen in order to live. |
| What are obligate anaerobes? | Organisms that must live in the absence of oxygen. |
| Are humans obligate aerobes or obligate anaerobes? | Humans = obligate aerobes (we need oxygen!). |
| How is botulism formed? | If the bacteria Clostridium botulinum gets into an oxygen-free environment that is filled with food, the bacteria grows rapidly; it produces toxins that cause botulism, a food poisoning that can cause death. |
| What are facultative anaerobes? | They are a group of bacteria that can live with or without oxygen. |
| What is binary fission? | It's a type of asexual reproduction in which an organism divides to produce 2 identical daughter cells. |
| What is asexual reproductio? | Asexual reproduction does not involved exchane or recombination of genetic information. |
| What is conjugation? | Conjugation is the process in bacteria and protists that involves an exchange of genetic information. |
| Explain the role of the donor and recipient in conjugation. | In conjugation, a long bridge of protein connects 2 bacterial cells; the donor transfers part of its genetic information to the other cell (recipient). The new comginations of genes increase the genetic diversity in that particular population of bacteria. |
| How is an endospore formed? | A bacteria produces a thick internal wall that encloses its DNA and a portion of its cytoplasm, forming an endospore. |
| Why might an endospore remain dominant for months or years? | If growth conditions are not favorable, the endospore becomes dormant until more favorable growth conditions occur. |
| What does the term "symbiosis" mean? | Symbiosis is a relationship in which one or both "partners" benefit. An example: E. coli in our intestines. |
| List some of the beneficial uses of bacteria in foods. | Bacteria are used in production of cheese, yogurt, buttermilk, sour cream, pickles, sauerkraut, vinegar from wine. |
| How does industry use bacteria? | Bacteria help clean up small oil spills, remove waste products and poisons from water, help mine minerals from the ground, synthesize druges & chemicals in genetic engineering. |
| Why do all vertebrate animals need bacteria in their intestines? | No vertebrate produces the enzymes needed to break down cellulose; bacteria does this. |
| Prove that the human digestive system and bacteria have a symbiotic relationship. | Bacteria get a warm safe home with food and free transportation; humans get help digesting food and making a number of vitamins we can't produce on our own. |
| What are saprophytes? | They're organisms that use the complex molecules of a once-living organism as its source of energy and nutrition. Example: how bacteria break down a fallen tree, recycle it, enrich the soil in which it grew. |
| How do bacteria help in sewage decomposition? | Bacteria grow rapidly in waste water; as they do, they break down complex compouds in the sewage into simpler compounds that produce purified water, nitrogen gas, and carbon dioxide gas; leftover products can be used as crop fertilizers. |
| What do bacteria provide that all organisms on earth must have to survive? | Nitrogen. (See pg. 371 in text) |
| What is nitrogen fixation? | Bacteria are the ONLY organisms capable of performing nitrogen fixation: the process by which nitrogen in the atmosphere is converted into a form that can be used by living things. |
| What is the purpose of "bio-prospecting" in Yellowstone Park? | A company hopes to find powerful heat-stable enzymes in these organisms for use in medicine, food production, and industrial chemistry. |
| Describe an episode of staphylococci food poisoning. | The toxin is carried throughout a person's body (once bad food is eaten); diarrhea, vomiting, nausea, abdominal cramps follow; recovery occurs in 24-48 hours. |
| Describe salmonella poisoning. | The toxin takes longer before the effects are felt; diarrhea, fever, chills, frequent vomiting, abdominal pain follow; it takes longer to recover from salmonella poisoning than from staphylococci poisoning. |
