Transcript 2-Bacteria Notes

June 2, 2016
(Really)
A.
Basic Characteristics
1.
2.
3.
4.
Single celled
No membrane-bound organelles
Nucleoid region
Microscopic
Identified by the following:
1.
a.
b.
c.
d.
Shapes
Chemical nature of their cell walls
The ways they move
The ways they obtain energy
 All
bacterial
cells have:




Cytoplasm
Ribosomes
Cell Membrane
Some bacterial
cells have:
Cell Wall
Plasmids
 Capsule
 Flagella
 Pili


1.
2.
3.
4.
5.
Cell wall – protects the cell &
gives it shape.
Plasmid – circular piece of DNA
separate from the genome
Capsule/Slime layer – protects
the cell & assists in attaching
the cell to other surfaces.
Flagella- motility
Pili- used in transfer of DNA
3.
.
Bacillus
Coccus
Spirilla
A.
Three basic shapes of bacteria
1. Bacillus = rod shape
2. Coccus = round or spherical
shape
3. Spirilla = spiral shape
• Cell Arrangements
– Diplo – cells are paired
– Staphylo – cells are in
grape-like clusters
– Strepto – cells are in
long chains
Two different types of cell walls are found
in eubacteria
A.
1.
2.
Gram Positive
Gram Negative
Gram staining helps to tell them apart
using two different types of dye
B.
1.
2.
Violet - primary stain
Red – counterstain
(more on this later!)
Binary Fission: bacterium
doubles in size, it replicates
its DNA and divides in half
A.
1.
Each daughter cell is a clone
of the parent
 Is
this sexual or asexual
reproduction?

Asexual
Bacillus cereus
A.
1.
2.
3.
4.
Found in soil
Straight rods
Arranged singly or in pairs
Cause of a lot of food borne illnesses
Aquaspirillum serpens
B.
1.
2.
3.
Found in fresh water
Spiral shaped
Arranged singly
Escherichia coli (E. Coli)
C.
1.
2.
3.
4.
5.
Straight rods
Arranged singly or in pairs
Named after pediatrician who discovered it
Digest food in your intestines (benefit to us)
Some strains are very harmful and can lead to
food borne illnesses
Staphylococcus epidermidis
D.
Epidermis = skin
Spherical shape
In clusters
Usually not pathogenic
1.
2.
3.
4.
Staphylococcus aureus
E.
Spherical shape
In clusters
Most common type of staph infections in
humans
MRSA: Methicillin-resistant S. aureus
1.
2.
3.
4.
a.
Highly resistant to antibiotics
Types of Genetic Recombination
B.
1.
2.
3.
Conjugation: process by which two living bacteria
bind together and one bacterium transfers genetic
information (PLASMIDS) to the other
Transformation: occurs when bacterium binds to and
then takes up DNA released by dead bacteria
Transduction: viruses carry portions of DNA from one
bacterium to another
Endospore: thick-walled, dehydrated
structures inside bacterium
C.
1.
2.
3.
Protects the cell against harsh environmental
conditions, such as heat and drought
May allow the bacterium to survive for
thousands of years
Not for reproduction, but for survival