Chapter 27 Flashcards
They thrive almost everywhere including places too acidic, salty, cold or hot for most organisms
Prokaryotes
There are more handful if what organism in fertile soil than number if people who have ever lived
Prokaryotes
Prokaryotes are divided into two domains
Bacteria and Archaea
Why is lakebed red?
Due to the presence of dinoflagellates.
Red Tide is caused by a “population explosion” of toxic, naturally occurring microscopic plankton (specifically, a subgroup known as dinoflagellates).
Prokaryotic cells measurements
Eukaryotic cells measurements
0.5-5um
10-100um
Three most common shapes of prokaryotic cells
Spheres (Cocci), rods (bacilli), and spirals
Important feature of nearly all prokaryotic cell
Cell wall
What is the function of cell wall of prokaryotes
Maintains cell shape
provides physical protection
prevents cells from bursting in a hypotonic environment
Eukaryotic cell walls are made of ?
Cellulose and chitin
Bacterial cell walls contain?
Peptidoglycan
A network of sugar polymers cross-linked by polypeptides
Peptidoglycan
Using what scientist classify bacterial species based on cell wall composition
Gram stain
Have less peptidoglycan and an outer membrane that can be toxic. More likely to be an antibiotic resistant
Gram-negative bacteria
Many antibiotics target peptidoglycan and damage cell walls often causes
Cell lysis
What happens to peptidoglycan in Gram-positive bacteria
Peptidoglycan traps crystal violet
