Download KINGDOM MONERA Bacterial Cell Shape

8/22/2010
KINGDOM MONERA
The Prokaryotes:
Archaebacteria and Eubacteria
• Bacteria are the smallest
organisms measuring from _____
micrometres.
• It contains a _______that provides
support and protection for the
contents of the cell. Some are also
covered by a _____ capsule.
• The cytoplasm contains
_________, responsible for the
formation of proteins and DNA.
• The DNA forms a single
chromosome and forms a _____
rather than a strand.
• Some bacteria have a whip-like
________ that act like propellers
moving the organism forward.
• Bacteria are ________ by their
shape, reaction to being stained,
nutrition and respiration.
• Bacteria are the most _________organisms living on the
Earth. (i.e. 10mL of soil contains 1 x 1010 bacteria.
• They are found in nearly every habitat studied, including
habitats that no other ___________ are able to withstand.
• Bacteria all share these five characteristics
-All bacteria are _______-celled
-All bacteria are ___________. Their DNA is not
surrounded by a membrane.
-Cell __________ in bacteria are not surrounded by
membranes.
-The DNA of bacteria is made of a single ____________.
-All bacteria reproduce asexually by _______ fission.
Bacterial Cell Shape
• Bacteria can be classified by shape.
-A spherical cell is called a _______ (pl. cocci)
-A rod-shaped cell is called a _________ (pl. bacilli)
-A spiral-shaped cell is called a _________ (pl. spirilla)
1
8/22/2010
Nutrition
Staining bacteria results in two forms:
gram-________ (purple) vs. gram ________
(pink).
• Nutrition means obtaining _______ and a source of ______
to produce the organic compounds needed for cellular
metabolism.
• Most bacteria are __________ and obtain energy by
breaking down organic molecules from their environment.
Some are _________, absorbing nutrients from living
organisms. Others are ___________, decomposing dead
organic matter.
• Some bacteria are autotrophs and produce their own
________ compounds. (example- cyanobacteria (blue-green
bacteria) are photoautotrophs using ______ for energy, but
they lack true chloroplasts.
Gram positive:
accepts crystal
violet stain.
Gram negative:
Peptidoglycan layer
is covered.
Nutrition
• Most are ___________ although some are
autotrophs.
• Some are parasites
which live off a
living _____
Mode of nutrition
Energy Source
Carbon Source
Photoautotroph
Light
Carbon Dioxide
Chemoautotroph
Inorganic Chemicals
Carbon Dioxide
Photoheterotroph
Light
Organic Compounds
Chemoheterotroph
Organic Compounds
Organic Compounds
• The autotrophic bacteria
either use ________ as a
source of energy
(chemoautotrophs) or
are _____________
(photoautotrophs).
• Some are
_______, feeding
off dead
organisms and
______ (i.e.,
decomposers).
Leucothrix mucor
2
8/22/2010
Respiration
• Chemical reactions take place on the _____ ______of the cell
membrane so that gases can pass into and out of cells easily.
• All living things must carry out cellular __________ to receive
energy. Bacteria differ in whether or not they require oxygen.
• If respiration requires oxygen, bacteria are termed _______. If
oxygen is absolutely necessary for survival they are called
________ aerobes.
• Bacteria that carry out respiration without oxygen are called
_________. Presence of oxygen kills some bacteria and these
are called obligate ___________. (example- Clostridium
botulinum produces toxins that can cause an extreme form of
food poisoning called botulism.)
• Another group of bacteria can survive with or without oxygen
and they are called __________ anaerobes.
Asexual - Binary Fission
• _________ reproduce by simply splitting in
two
• The DNA is copied and the ____ divides into
two identical cells.
Sexual - Conjugation
Reproduction
• Bacteria reproduce
asexually and divide by the
process of _______ ______.
• In binary fission, the parent
cell divides into two
offspring cells that are
completely ________.
• There is no exchange of
genetic material so the
process is _______.
• E. coli produces between
_____ ________bacteria in
12 hrs
• When conditions begin to ____,
either through decrease of food
or space, or cooler
temperatures, some bacteria
take part in a type of sexual
reproduction called __________.
• In conjugation the two cells join
briefly and one cell donates
some _____ (called plasmid) to
the other one.
• Sexual reproduction _________
genetic information from two
different individuals and
increases variation.
• Transformation - Bacteria can also pick up pieces
of DNA from the __________
• Sexual reproduction combines ______ from two
different individuals and increases variation.
__________ do not technically reproduce
sexually but can mix genes with one another.
3
8/22/2010
• Transduction - sometimes ________
transfer pieces of DNA from one cell to
another.
• ________ is a large source of genetic
diversity in bacteria.
Under ultraviolet light in a Petri dish containing laundry whitener, symbiotic
bacteria with a mutant bluB gene (lower right) fluoresce brightly, while the same
bacteria with no mutation only glow slightly (top right), and bacteria with
another mutation (in the exoY gene) are completely dark.
• When growth conditions
become extremely
unfavorable, many ____
_______ bacteria form
structures called
endospores.
• Endospores are DNA and a
small amount of ________
enclosed in a tough cell
wall.
• They are ________ to
extremes in temperature,
drying, and harsh
chemicals.
Kingdom Monera Classification
The Phyla
_________
Gram
negative
________
Gram
positive
Gracilicutes
_____bacteria
Non-photosynthetic
_________bacteria
Exotic cell wall
Archeabacteria
________bacteria
oxygen producing
_____bacteria
(rod or cocci)
Live in sediments and lakes.
Release sulpher
____________
Firmicutes
non-oxygen producing
Most pathogenic
i.e. Lyme Disease
Salmonella
Others: E.coli in gut
_________
No cell
wall
Cyanobacteria
(blue-green
algae)
C. Botulinum
S. pneumoniae
_______bacteria
(other shapes)
Dental/gum
diseases
4
8/22/2010
Mendosicutes
Tenericutes
_______bacteria
(ancient)
__________
Other strains
of pneumonia
The pros and cons of Bacteria
• Bacteria ________ atmospheric nitrogen into a useable form
of nitrogen. (nitrogen-fixers)
• Bacteria play an important role in recycling by ________ down
dead and decaying organic matter. Used to eliminate or
________ toxic and hazardous waste and spills. Also used in
sewage treatment to decompose the 5 ______ kg of solid
waste produced daily.
• Bacteria is used to produce ______ foods that help maintain a
healthy balance of microorganisms in the digestive system.
• Only a small percentage of prokaryotes are ________, or
disease causing. These bacteria produce deadly toxins in the
human body that cause disease symptoms. ___________ are
seldom fatal and cause fever, vomiting and diarrhea. E. coli,
Salmonella. __________ are highly toxic, do not cause a fever
and are often fatal. Tetanus and botulism.
Example- Toxins released by the bacterium Streptococcus
pneumoniae may result in symptoms of pneumonia.
Anaerobic
Methanogens- live
in the gut of
animals, swamps
and marshes.
Produce all the
methane ___found
in the Earth’s
atmosphere.
Halophiles“___-______”
found in salt
lakes such as the
Dead Sea.
Thermophiles –
_______ hot,
acidic
environments
such as hot
springs.
Review Questions
1. Why are bacteria classified in their own kingdom and not with plants, animals,
protists, or fungi?
2. What features are shared by prokaryotes?
3. What feature(s) might cause cyanobacteria to be classified as plants by some
taxonomists?
4. Describe three shapes that bacteria can have.
5. Why is endospore formation important to bacteria?
6. What method of reproduction is used in bacteria?
7. What is conjugation in monerans? Why is it important?
8. How is conjugation different from transformation?
9. A protective slime coat around some species of bacterium known as a ____
makes them more capable of causing disease.
10. Why are monerans considered more primitive than protists?
11. What is the difference between a saprobe and a parasite?
12. How do obligate aerobes differ from facultative aerobes?
13. _____ are organisms that die in the presence of oxygen.
14. Monerans belong to a group of organisms known as prokaryotes. Discuss the
differences between eukaryotes and prokaryotes in terms of cell wall, nuclear
membrane, and chromosomes.
15. Why does dried or salted food resist spoiling by bacteria?
16. Give specific examples showing the importance of microbial sterility in
a) your kitchen
b) a microbiology lab
17. Describe the results if all bacteria died.
18. Endospores
a) are produced by viruses
b) are reproductive structures
c) are very delicate and can easily be killed d) are resting structures
19. An obligate anaerobe would
a) grow equally well with or without free oxygen
b) grow well with free oxygen but better without it
c) die without oxygen
d) grow only in the absence of free oxygen
20. Why are archaebacteria considered the oldest organisms on Earth?
5