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Published byPaulina Bond Modified over 9 years ago
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Discovered in the late 1600s by Anton van Leeuwenhoek, by accident. Bacteria are prokaryotes (single celled) Their genetic material is not contained in a nucleus.
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Surrounded by a rigid cell wall. Just inside the cell wall is the cell membrane. The region inside the cell membrane is called the cytoplasm. Within the cytoplasm are tiny structures called ribosomes and the cells genetic material. May also have a flagellum, which helps with movement.
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Spherical Rodlike Spiral The chemical makeup of the cell determines its shape. Shapes, help identify types of bacteria
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The average size for a bacterial cell is 0.5 to 1 micrometer. EcoliStreptococcus
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Some bacteria are autotrophs, to eat they Capture the sun’s energy Energy form chemical substances in their environment. Some bacteria are heterotrophs, to eat they Consume other organisms Consume food other organisms make Consume a variety of foods from milk and meat to decaying leaves.
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Respiration is the process of breaking down food to release its energy. Most Bacteria need oxygen to break down their food,(Aerobic bacteria) There are a few kinds of bacteria that few do not need oxygen(Anaerobic bacteria).
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When bacteria have plenty of food, the right temperature, and other suitable conditions they thrive and multiply quickly. Bacteria can reproduce as often as every 20 minutes! There are three types of bacterial reproduction.
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Asexual reproduction is a reproductive process that involves only one parent and produces offspring that are identical to the parent. Bacteria reproduce by a form of asexual reproduction called binary fission. Binary fission means one cell divides to form two identical cells. Each bacteria has an exact copy of the parent cell’s genetic material
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Some bacteria under go simple sexual reproduction, which means two parents combine their genetic material to produce a new organism which is different from the parent cells. This is called conjugation, when one bacterium transfers some of its genetic material into another bacterium through a thin, threadlike bridge that joints the cells. Figure 10 pg 52 The result is a new bacteria with a new combination of genetic material.
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Bacteria that live in harsh conditions use the process of forming endospores. An endospore is a small, rounded, thick-walled resting cell that forms inside a bacterial cell. It contains the cell’s genetic material and some cytoplasm Because endospores can resist freezing, heating, and drying they can survive for many years, until if finds a suitable environment, then the bacterial opens up and multiplies.
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Most bacteria are harmless or helpful! Bacteria are involved in oxygen and food production, environmental recycling and cleanup, and in health maintenance and medicine production.
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As autotrophic bacteria use the sun’s energy to produce food, they also release oxygen into the air.
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Cheese, sauerkraut, pickles, apple cider, milk, buttermilk, yogurt, sour cream all need bacteria. Bacteria can cause food to spoil by breaking down the food’s chemicals. Heat Cold Pasteruization
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Decomposers Organisms that break down large chemicals in dead organism into small chemicals. “Nature’s recyclers” breaking down dead leaves Nitrogen-fixing bacteria Live in soil Help convert nitrogen gas from the air into nitrogen products that plants need to grow.
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Some bacteria cleanup oils spills in the ocean or gas that leaks into the soil under a gas station.
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Bacteria help you digest food! Make vitamins for your body. Take the place of disease causing bacteria Scientist make medicine from bacteria Human insulin
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