Prokaryotes + Bacteria notes Flashcards
General Characteristics: Prokaryotes. (6 characteristics)
■ No nucleus (genetic material flows freely in cytoplasm)
■ No membrane-bound organelles
■ Unicellular
■ Energy produced using
free-floating cytoplasmic
enzymes
■ Most possess
cell walls
■ Cell walls made of
Peptidoglycan
How are archaea similar to bacteria?
Similar to bacteria in size, shape and component
How are they different? Different cell wall structure from bacteria
Germ theory
A specific
microorganism can
cause a specific disease
in people
Pathogen
■ Disease causing agents
■ Some indeed cause
disease, some are very
important for us to live
Bacteria as a Probiotic good bacteria
Activia yogurt
Cheese
Major Characteristics of Bacteria (Not on worksheet)
Bacteria are classified based on:
1) Cell shape
2) Motility (method of movement)
3) Nutritional modes
4) Reproduction
5) Cell wall structure
Cell Shape (THREE SHAPES AND THREE ARRANGMENTS OF BACTERIA)
Variety of shapes include:
■
Spherical =
cocci
■
Rod-shaped =
bacilli
■
Spiral shaped =
spirilli
Variety of arrangements include:
■
Diplo =
paired
■
Staphylo =
clusters
■
Strepto =
chains
MOTILITY (TWO WAYS BACTERIA MOVE)
Tools for motility:
■ Flagella
: whip-like structures propel bacteria
forward
■ Corkscrew motion
: used by spirilli bacteria
What is the name for asexual reproduction of bacteria?
A) Binary Fission
■ Asexual
reproduction
■ Results in 2 genentically
identical cells
■ DNA replicates
■ Cell growth
■ Cell membrane pinches in
middle
What is the name for sexual reproduction of bacteria?
B) Conjugation
■ Sexual’
reproduction
■ Bacterial cells temporarily
join via a mating bridge to exchange genetic material
■ Plasmids
are exchanged
(separate rings of DNA from
cell’s main chromosome)
What is the major component of the Cell Wall
Functions:
■ Provides structure and
protection
■ Maintains shape of cell
Peptidoglycan
■ Major component of cell wall
■ Made of polymers of
carbohydrates and amino acids
Which bacteria have thicker cell walls gram positive
Gram positive:
■ Thick layer of peptidoglycan
■ Stain dark blue or violet
■ Most **pathogenic bacteria **are gram positive
Which bacteria have gram negative thin or thicker
■Gram negative:
■ Thinner layer of peptidoglycan found between outer and inner membrane
■ Stain pink
Antibiotic Resistance (3-4 point form)
■ In any population, some bacteria will be antibiotic resistant and
survive.
■ Resistance can also transfer from one bacterium to another through
conjugation
■ The overuse of antibiotics can cause bacteria to become resistant to
many antibiotics making them no longer effective
■ It is important to only use antibiotics when necessary and
complete the full dose.
