1. Section 2-Bacteria

2. The Bacterial Cell
Anton van Leeuwenhook makes an accidental appearance once again with the discovery of bacteria in the 1600s-by looking at the scrapings of his teeth, he discovered “worm-like organisms”

3. Cell Structures
Bacteria are PROKARYOKES because they lack structures such as the mitochondria and golgi bodies.
The genetic material in their cells is NOT contained in the nucleus. Bacteria lack a nucleus.
The cytoplasm contains the ribosomes and genetic material.

4. How Do Bacteria Move?
Bacteria may also have flagellum (whip-like structures that help bacteria move)
A Flagellum moves the cell by spinning in place like a propeller.

5. Cell Shapes and Sizes Bacteria vary in size.
Bacteria have three common shapes: spherical, rod-like or spiral.
The chemical makeup of the cell wall determines the shape of the bacterial cell.
The shape of the bacteria helps scientist identify the type of bacteria.

6. Obtaining Food and Energy
Bacteria must have a source of food and a way of breaking down food to release its energy.
Bacteria can either be autotrophic or heterotrophic.
Autotrophic bacteria use energy from the sun or can use chemicals from their environment to maker their food.
Heterotrophic bacteria consume other organisms or the food other organisms make.

7. Respiration
This is the process of breaking down food for a source of energy.
Some bacteria need oxygen in order to break down their food.

8. Reproduction
When bacteria have plenty of food, the right temperature and other suitable conditions, they thrive and reproduce. (Bacteria can reproduce in as quickly as 20 minutes!)
Bacteria reproduce by a process called binary fission.
Binary fission is a form of a-sexual reproduction in which one cell divides to form two identical cells. The cell duplicates its genetic material and then divides into two separate cells. Each new copy receives a copy of the parents genetic material, ribosomes and cytoplasm.

9. Continued
Asexual reproduction is a reproductive process that only involves one parent and produces offspring identical to the parent.
(Imagine your mom only having you, and when you were born you were identical to your mother!)

10. Sexual Reproduction
Some bacteria at times undergo sexual reproduction.
Sexual reproduction requires two parents to combine genetic material to produce a new organism that differs from the parent cells.
Another form of sexual reproduction is conjugation. Conjugation is the process of offering some genetic material to another bacterium through a thread-like bridge. After the transfer, the cells separate.

11. Endospore Formation
During times of harsh conditions, bacteria form endospores to survive.
Endospores are small, rounded, thick- walled cell that contains some of the bacteria’s genetic material and cytoplasm.
Because endospores can resist severe freezing, heating and drying, they can survive for many years.

12. Bacteria in Nature
Bacteria are involved in oxygen and food production, environmental recycling and cleanup and aid in health maintenance and medicine production.
Scientist credit autotrophic bacteria with providing the first sources of oxygen in the air.

13. Bacteria and Food Production
During pasteurization, the food is heated to a temperature that is high enough to kill most harmful bacteria without changing the taste of the food.
Examples of foods affected by bacteria: cheese, pickled vegetables, dried meats, sourdough bread

14. Bacteria in the Environment
Heterotrophic bacteria contribute to the decomposition of things in the environment.
Decomposers are organisms that break down large organisms into small chemicals. They are known as nature’s recyclers.
Some bacteria help to clean Earth’s land and water. Ex: the bacteria that “eats” oil from the ocean.

15. Health and Medicine
Bacteria in your body actually keeps you healthy! Ex: Intestinal bacteria keeps your body regular.
Some bacteria make vitamins your body needs.
Bacteria is also used to make medicines and can be manipulated to make human insulin.