discovered in the late 1600s by anton van leeuwenhoek, by accident. bacteria are prokaryotes...
TRANSCRIPT
BACTERIA
BACTERIA INFORMATION
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.
BACTERIAL CELL STRUCTURE
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.
BACTERIAL CELL
CELL SHAPES
Spherical Rodlike Spiral The chemical makeup of the cell
determines its shape. Shapes, help identify types of bacteria
CELL SIZES
The average size for a bacterial cell is 0.5 to 1 micrometer.
Ecoli Streptococcus
OBTAINING FOOD AND ENERGY
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.
RESPIRATION
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).
REPRODUCTION
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.
ASEXUAL REPRODUCTION
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
SEXUAL REPRODUCTION
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.
ENDOSPORE FORMATION
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.
BACTERIA AND NATURE
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.
OXYGEN PRODUCTION
As autotrophic bacteria use the sun’s energy to produce food, they also release oxygen into the air.
FOOD PRODUCTION
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
ENVIRONMENTAL RECYCLING
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.
ENVIRONMENTAL CLEANUP
Some bacteria cleanup oils spills in the ocean or gas that leaks into the soil under a gas station.
HEALTH AND MEDICINE
Bacteria help you digest food! Make vitamins for your body. Take the place of disease causing
bacteria Scientist make medicine from bacteria
Human insulin