Prokaryotic Profiles Flashcards
What are the three ways that prokaryotes can be distinguished from eukaryotes?
packing of genetic material (lack of nucleus and histones)
makeup of their cell wall
internal structure (lack of membrane bound organelles)
What do ALL bacterial cells possess?
Cell Membrane Cytoplasm Ribosomes Cytoskeleton One (or a few) Chromosome(s)
What do MOST bacterial cells possess on top of what ALL bacterial cells already possess?
A cell wall (most are made of peptidoglycan)
A surface coating called glycocalyx
What do SOME BUT NOT ALL bacterial cells possess?
Flagella, pili, fimbriae
Outer membrane
Plasmids
Endospores
What are Plasmids
circular pieces of DNA that are not chromosomes, not essential to life though benefit the organism in some way
What does a colony of bacteria consist of?
billions of bacteria
How do most prokaryotes exist?
as unicellular organisms
What is it called when bacteria/ prokaryotes act as a group?
biofilms/ colonies.
Find biofilms in the toilet, mucus on teeth
Size of Prokaryotes
can range from 0.05-0.2 um (“nanobes) to 750 um
Pleomorphism
Cells of one species may vary in shape and size due to variations in cell wall structure
the occurrence of more than one distinct form of natural object.
Coccus
Round bacteria
shape of staphlyocci
Cocobacillus
in between rod shaped and coccus shaped bacteria
Rod/ Bacillus
rod shaped, long depending on type
Vibrio
Curved Rod Shaped
Spirilium
Short Spirals
Spirochete
Long spirals
endoflagella: allow for movement
Branching Filaments
more complex structures of bacteria
What is it called when 2 bacterial cells are stuck together in a one plane division?
Diplo
for coccus cells: diplococcus
What is it called when there is a chain of bacterial cells together in a one plane division?
strep
for coccus cells: streptococcus
What is it called when there are bacterial cells (cocci) in packets of four?
tetrad
What is it called when there are bacterial cells in packets of 8-64
Sarcina
What are the prokaryotic propellers?
Flagella
What are the 3 distinct parts of Flagella?
And what is it comprised of
Basal Body: Keeps it in place
Hook: Provide the bacterium with locomotion
Filament
Comprised of many proteins
Where does Flagella get it’s energy from?
ATP synthase: the protons moving across membranes makes enough energy for flagella to move
Flagellar Arrangements
Monotrichous
Lophotrichous
Amphitrichous
Peritrichous
Monotrichous
single flagellum
Lophotrichous
small tufts of flagella
Amphitrichous
flagella at both poles of the cell
Peritrichous
flagella dispersed randomly over the surface of the cell
bacterial movement
In response to chemical signals (Chemotaxis: attracted or repelled by a chemical signal)
Receptors bind extracellular molecules, which triggers flagellum to rotate
What are the types of prokaryotic appendages and what are they used for?
Fimbriae: attachment; shorter than flagella
Pili: used for attachment and genetic eschange during conjugation
What is the Glycocalyx?
Composed of what?
What is it used for?
“Protein Sugar Shell: composed of polysaccharides, proteins or both
Vary in thickness
They are used to avoid phagocytosis and used for adhesion
What is a function of the Glycocalyx in regard to our body
help the bacterial cell to be “unrecognized” by the body, so that infection goes unnoticed
Capsules are;
Bound tightly to the cell
visible by negative staining