Transcript C, O, N - Madeira City Schools

Classification of Bacteria
A. Domain Archaea – means “ancient bacteria”
1. These are found in extreme habitats
a. deep in mud, salty conditions, extreme pH and temp.
2. Prokaryotic cell
B. Domain Bacteria
1. Heterotrophs – cannot make their own food
a. decomposers (helps recycle nutrients)
b. parasitic (3%)
2. Photoautotrophs – make their own food using light
a. contain pigments
b. algae like bacteria – these are important producers for
aquatic ecosystems
c. “cyanobacteria” – name of the bacteria that does this
3. Chemoautotrophs – make their own food using chemicals
a. use sulfur and nitrogen to make food (this is the rotten egg smelling gas)
b. some live on the roots of plants and help the plant get
nitrogen through nitrogen fixation…”Rhizobacteria”
Mutualism – bacteria has home, plant gets nitrogen
II. Structure of Bacteria
A. Type of cell – Prokaryotic
1. no nucleus or membrane bound organelles
B. DNA is found in the cytoplasm as one circular chromosome
C. Contains ribosomes (not membrane bound)
D. Drawing of a typical cell:
1. Flagella – moves bacteria
2. Chromosome – one circular piece…area that contains
the chromosome is called the “nucleoid” region
3. Pili – attaches bacteria to surfaces and aids in sexual
reproduction. It is an extension of the cell membrane
4. Cell Membrane – regulates what goes into and out of
cell, also involved in making ATP
5. Cell Wall – protection
6. Capsule – protection (not all bacteria have this)…these
types cause more disease in us.
C. Shapes of bacterial cells
1. Sphere – “coccus”
2. Rod – “bacillus”
3. Spiral – “spirillum”
D. Arrangement of bacterial cells
1. cells are paired – “diplo”
2. Clusters of cells – “staphylo”
3. Chains of cells – “strepto”
E. Naming bacterial cells relates to the above. The genus
name is a combination of arrangement + shape. Name the
following:
Spirillum
Bacillus
Staphylococcus
III. Adaptations of Bacteria
A. Endospores
1. A hard outer covering that enables the cell to live in a
dormant state when conditions are not favorable for
living.
2. resistant to drying out, boiling, chemicals
3. can survive for thousands of years
4. kill them by pressure cooking or autoclave
5. examples of bacteria that do this are:
the bacteria that causes botulism
the bacteria that causes tetanus
Artist, Charles Bell, paints this picture of a soldier in the last
stages of tetanus.
Binary Fission
IV. Reproduction
A. can’t reproduce via mitosis
because they have no
nucleus
B. Binary Fission: asexual
reproduction (there is no
exchange of genetic
information)
1. Chromosome is replicated
2. Copies of chromosome
attach to the cell
membrane
3. Cell grows and the copies
separate
4. Cell divides in two as a
partition forms down the
middle
C. Conjugation: Sexual Reproduction (there is an exchange of
genetic information)
1. Transfer of part of the
chromosome through the
pili to another cell.
2. Why is this type of
reproduction important?
V. Economic Importance
A. Nitrogen fixation – bacteria take Nitrogen from the air and
“fixes” it to be a form that plants can use for proteins and
DNA.
B. Decomposition of biodegradable material (trash, leaves, etc)
C. Recycling of nutrients due to decomposition (C, O, N)
D. Food
1. yogurt
2. cheese
3. Vinegar
4. butter
5. pickles
6. sauerkraut
E. Medicine – antibiotics
F. Gene Cloning and product producing (remember pGLO lab)