Transcript 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
1.
2.
Cell wall – protects the cell &
gives it shape.
Outer membrane – protects
the cell against some
antibiotics (only present in
some)
3.
4.
5.
Cell membrane – regulates movement of
materials into & out of the cell; contains enzymes
important to cellular respiration.
Plasmid – circular piece of DNA that contains some
genes obtained through genetic recombination.
Capsule & Slime layer – protect the cell & assist in
attaching the cell to other surfaces.
A.
Three basic shapes of bacteria
1. Bacillus = rod shape
2. Coccus = round or spherical
shape
3. Spirilla = spiral shape
1.
2.
3.
Diplo – cells are paired
Staphylo – cells are in grapelike clusters
Strepto – cells are in long
chains
Two different types of cell walls are found
in eubacteria
A.
1.
2.
Bacteria cells containing peptidoglycan
Bacteria with an outer layer of lipid and
carbohydrate molecules
Gram staining helps to tell them apart
using two different types of dye
B.
1.
2.
Violet - primary stain
Red - counterstain
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
Types of Genetic Recombination
B.
1.
2.
3.
Conjugation: process by which two living bacteria
bind together and one bacterium transfers genetic
information 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
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