Transcript Identifying Prokaryotes

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Bacteria data sheet
Bacteria
Pg.78
Pg.79
Identifying Prokaryotes
Factors needed to identify a prokaryote:
1) Shape
a) Bacilli: rod-shaped
Identifying Prokaryotes
b) Cocci: spherical (bead-like)
Identifying Prokaryotes
c) Spirilla: spiral or cork-screw shaped
Identifying Prokaryotes
2) Movement: some move, others do not.
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Flagella: whip-like structures used for movement.
Some move like snakes, spiral, glide.
Growth and Reproduction
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Bacteria may grow and divide in 3 ways:
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1) Binary Fission: copies DNA and divides in
half; no exchange or recombination of DNA
(asexual).
Growth and Reproduction
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2) Conjugation: bridge between 2 cells;
genes are exchanged between the 2 bacteria.
Growth and Reproduction
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3) Spore Formation: in harsh conditions,
bacteria form spores for protection.
In favorable conditions bacteria can reproduce very quickly. Some bacteria can
reproduce every 20 minutes, producing an enormous number of bacteria
quickly. If bacteria always reproduced this fast, they would cover the surface of
the earth within a few weeks. Look at the data below and graph.
Time (Minutes)
20
40
60
80
100
120
140
160
180
200
220
240
260
280
300
Bacteria Cells
2
4
8
16
32
64
128
256
512
1,024
2,048
4,096
8,192
16,384
32,768
Importance of Bacteria
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Bacteria are essential to all forms of life
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A) Decomposers: help ecosystem recycle
nutrients and break down compounds in sewage
treatments
B) Nitrogen Fixers: convert N2 gas into form
plants can use and recycles it in atmosphere
C) Human Uses: food, beverages, industrial,
purification, etc.
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E. coli: help make vitamins in intestines
Important Bacterial Diseases
Streptococci Infections
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Streptococci (strep) are bacteria that are commonly
found harmlessly living in the human respiratory, gut and
genitourinary systems. Several species are capable of
causing disease in humans, including skin diseases.
Impetigo
Cellulitis
Necrotising faciitis
E. Coli Infections
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Most E. coli are harmless and actually are an important
part of a healthy human intestinal tract. However, some
E. coli are pathogenic, meaning they can cause illness,
either diarrhea or illness outside of the intestinal tract.
Meningitis
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Meningitis is a disease caused by the inflammation of
the protective membranes covering the brain and spinal
cord known as the meninges. The inflammation is
usually caused by an infection of the fluid surrounding
the brain and spinal cord.