Download Kingdom Monera : Introduction - Mr. Lesiuk

Kingdom Monera : Introduction
A) Prokaryotic Cell Vs. Eukaryotic Cells
Feature
Nucleus/Nucleolus
Prokaryotes
None
Eukaryotes
Present
Size (diameter)
1-10 um
10-100um
Membrane Bound
Organelles
None
Present
Cell Division
Binary Fission
Mitosis
- Chemical reactions needed by the cell occur
in the cytoplasm of the prokaryotic cell.
- In Eukaryotic cells, these reactions occur in
the organelles, where all needed materials are
stored.
- As a result of their unorganized cellular
reactions, Prokaryotes are not as
metabolically efficient as eukaryotes.
- All Prokaryotic organisms belong to one
Kingdom : Monera
(Now classified into two kingdoms) :
A) Archaebacteria B) Eubacteria
B) Characteristics of Kingdom Monera
1. Prokaryotic Cells
2. Smallest living things made of cells.
3. Most are single-celled (unicellular). Some
live in colonies (groups)
4. Vary widely in shape (and size) - 3 main
shapes Coccus (spherical), Spirillum (spiral),
and Bacillus (rod-shaped).
5. Some move with flagella others are at the
mercy of water currents.
6. Some make their own food (autotrophic :
self-nourishers) others must eat or absorb
pre-made food (heterotrophic : feed on
others)
- Some of these heterotrophs live on dead
organic material. These organisms are
classified as being SAPROPHYTIC
heterotrophs.
- Other heterotrophs absorb nutrients from a
living host. These organisms are classified as
being PARASITIC heterotrophs.
- Any parasitic bacteria that causes a disease is
classified as a PATHOGEN.
C) Bacterial Structure and Function:
A Typical Moneran shown below:
a) Cell Wall: Gives the Moneran protection and shape.
b) Cell Membrane: Control which substances enter and
leave the cell.
c) DNA: Set of instructions on how to build and control
cells by making various types of proteins. Sits naked as
a "nucleoid"
d) Cytoplasm: Jelly like substance in the cell which
contains liquids, nutrients and gases needed by the cell
to run various chemical reactions.
e) Flagellum (flagella) : Whip-like tail for movement,
NOT present on all bacterial cells.
f) Pilus (pilli) : Hairlike appendages used to help
bacteria adhere (stick) to other cells.
D) Classifying The Monerans
We will look at three Phyla
1. Eubacteria (“True Bacteria”) – Now its own kingdom
2. Cyanobacteria (Blue-green Bacteria)
3. Archaebacteria (“Ancient Bacteria”) – Now its own
kingdom.
1. Eubacteria:
- These true bacteria, have the characteristics common
to the typical moneran described earlier.
2. Cyanobacteria:
-Produce their own food (autotrophic) by
photosynthesis.
- Many are blue-green, but others are yellow, brown or
red; depending on what type of pigment they use to
capture sunlight.
- Form base of many aquatic food chains.
3. Archaebacteria:
- Bacteria that require extremely harsh environmental
conditions.
-Thrive in such conditions as:
salty, low pH, or high temperature
- One group (methanogens) produce methane gas and
are used in sewage treatment processes.
Ex. Methanosarcina
Colony Of
Methanosarcina
Black Smoker
Environment
E) Identifying Bacteria:
1. Gram Negative Bacteria
- Most have thinner cell walls susceptible to breaking.
- Turn pink when adding red dye (safranine), they do
not absorb purple dye (crystal violet)
Ex. E-coli
Ex. Veillonella
- Common in the
intestinal tract
- Main component of dental
plaque
2. Gram Positive Bacteria
- Most have a thicker rigid multi-layered cell wall.
- Absorb and retain dark purple stain (crystal violet).
- Common to soil, skin and mucous membranes.
Ex. Streptococcus
- Common types of streptococcus cause a number of
diseases: scarlet fever, pharyngitis (sore throat),
pneumonia etc.
- Produce toxins that destroy phagocytes.
- Release enzymes to digest the body’s connective tissues
to spread infection.
3. Wall-less Prokaryotes
- Smallest monerans
- No cell wall, only a cell membrane.
- No definite shape
Ex. Mycoplasmas (mike-o-plz-maz)