1. BACTERIA Ch. 2.2

2. Anton van Leeuwenhoek

3. 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.

4. 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.

6. 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)

8. 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.

9. D. Cell Sizes 1. Bacteria vary greatly in _size_. They are measured in _microns_. 2. One micrometer is one _millionth_ of a meter.

10. 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).

11. Respiration B. The process of breaking down food to release energy is called _respiration_.

12. 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.

13. Binary Fission

14. 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.

15. Conjugation

16. 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.

18. 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_.

19. Decomposers