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BACTERIA. Ch. 2.2. Anton van Leeuwenhoek. I. The Bacterial Cell. A. Anton _van_ _Leeuwenhoek_ first discovered bacteria by accident. He made _microscopes_ as a hobby. He liked to look at scrapings from his _teeth_ to look at tiny, _wormlike_ organisms. B. Cell Structures.

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bacteria

BACTERIA

Ch. 2.2

i the bacterial cell
I. The Bacterial Cell
  • A. Anton _van__Leeuwenhoek_first discovered bacteria by accident.
  • He made _microscopes_as a hobby. He liked to look at scrapings from his _teeth_to look at tiny, _wormlike_organisms.
b cell structures
B. Cell Structures
  • 1. _Bacteria_are prokaryotes ( Cells _without_ a nucleus)
  • 2. The genetic material in bacterial cells is _NOT_found in a nucleus.
  • 3. Bacteria _lack_many other structures found in cells of eukaryotes (cells _with_a nucleus)
  • 4. Most bacterial cells are surrounded by a rigid _cell__wall_, which protects the cell.
cell structures
Cell Structures
  • 5. Inside the Cell Wall is a _cell__membrane_, which controls what material moves in and out of the cell.
  • 6. Inside the cell is the _cytoplasm_, a gel-like material.
  • 7. _Ribosomes_are chemical factories where proteins are produced.
  • 8. _Genetic_material is found in the cytoplasm.
  • 9. A bacterial cell may have a _flagella_, a long whip-like structure used for movement.

(plural is flagellum)

c cell shapes
C. Cell Shapes
  • 1. Three basic shapes _spherical_, _rodlike_and _spiral_.
  • 2. It is the _chemical_make-up of the cell that determines the shape of the bacterial cell.
d cell sizes
D. Cell Sizes
  • 1. Bacteria vary greatly in _size_. They are measured in _microns_.
  • 2. One micrometer is one _millionth_of a meter.
ii obtaining food and energy
II. Obtaining Food and Energy
  • A. Bacteria must have a source of _food_and a way of breaking down the food to release its _energy_.
  • 1. Some bacteria are _autotrophs_(make their own food).
  • 2. Some bacteria use _energy_from the chemicals in the environment.
  • 3. Some bacteria are _heterotrophs_(cannot make their own food).
respiration
Respiration
  • B. The process of breaking down food to release energy is called _respiration_.
iii reproduction
III. Reproduction
  • A. When _bacteria_have plenty of _food_, the right temperature and other suitable conditions they thrive and _reproduce_frequently.
  • B. _Binary__fission_is when 1 bacterial cell becomes 2.
  • C. _Asexual_reproduction involves only 1 parent and produces offspring identical to the parent.
reproduction
Reproduction
  • D. _Sexual_reproduction involves 2 parents who combine their genetic material to produce a new offspring
  • E. _Conjugation_is a process where 1 bacterial cell transfers genetic material into another bacterial cell.
  • F. Some bacteria can survive harsh conditions to form an _endospore_, a small rounded thick-walled resting cell that forms inside a bacterial cell.
iv the role of bacteria in nature
IV. The Role of Bacteria in Nature
  • A .Most Bacteria are either _harmless_or _helpful_ (Some cause diseases).
  • B. Bacteria release _oxygen_into the air to help keep oxygen levels in the air stable.
  • C. Helpful bacteria make food. List some foods bacteria help make: Cheese, pickles, apple cider, yogurt, sour cream, dried meat,soy sauce, chocolate beverages, sourdough bread. 
  • D. Some bacteria spoil food but refrigerating/heating food _slows_down food spoilage.
helpful bacteria
Helpful Bacteria
  • E. _Pasteurization_= food is heated to a temperature that is high enough to kill most harmful bacteria without changing the taste of the food (Named after Louis Pasteur).
  • F. _Decomposers_are organisms that break down large chemicals in dead organisms into small chemicals. They are “nature’s recyclers”.
  • G. Some bacteria help to clean up Earth’s _land_and _water_.
  • H. Bacteria in your _intestines_help you digest food. Scientists use bacteria to make _medicine_.
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