Bacteria

1
Bacteria

• Chapter 18

2
Identifying Prokaryotes

• Factors needed to identify a prokaryote
• 1) Shape
• a) Bacilli rod-shaped
• b) Cocci spherical (bead-like)
• c) Spirilla spiral or cork-screw shaped
• 2) Movement some move, others do not
• Flagella whip-like structures used for movement
• Some move like snakes, spiral, glide

3
Bacillus
Spirilla
Cocci
4
Growth and Reproduction

• Bacteria may grow and divide in 3 ways
• 1) Binary Fission copies DNA and divides in
  half no exchange or recombination of DNA
  (asexual)
• 2) Conjugation bridge between 2 cells genes are
  exchanged between the 2 bacteria
• 3) Spore Formation in harsh conditions, bacteria
  form spores for protection

5
Binary Fission
Conjugation
Endospore
6
Importance of Bacteria

• Bacteria are essential to all forms of life
• 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.
• E. coli help make vitamins in intestines

7
Streptococci Infections

• 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
8
E. Coli Infections

• 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.

9
Meningitis

• 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.