Prokaryotic Profiles: The Bacteria and Archaea Part 1 Flashcards
What are the three ways that prokaryotes can be distinguished from eukaryotes?
Packaging of genetic material
The makeup of their cell wall
Their internal structure
Packaging of genetic material-prokaryotes
Lack of nucleus and histones
Makeup of the cell wall-prokaryotes
Peptidoglycan and other unique chemicals
Internal structure - prokaryotes
Lack membrane-bound organelles
ALL bacterial cells possess…
Cell membrane Cytoplasm Ribosomes Cytoskeleton One or a few chromosomes
MOST bacterial cells possess..
Cell wall
Surface coating called glycocalyx
Some, but not all bacterial cells possess..
Flagella, fimbriae and pilli
An outer membrane
Plasmids
Endospores
What are plasmids?
Circular pieces of DNA that are not chromosomes, additional genetic material that is not essential for survival but usually benefits the organism in some way
Most prokaryotes exist as ________ organisms
Unicellular
Sometimes, when prokaryotes are not unicellular, they can act as a _______, in _______, or in ______
Group
Colonies
Biofilms
The size of prokaryotes can range from _____ to _____μm (“nannies”) to _____ μm
0.05
0.02
750
Cells of one species may vary in ___ and _____
Shape
Size
Pleomorphism
Change in shape and size caused by variations in cell wall
What is a colony?
Billions of bacteria
Coccus
Spherical or round shaped (can also be oval, bean shaped, etc)
Rod / bacillus
Cylindrical cell
Vibrio
Singly occurring rods that are gently curved
Coccobacillus
Really short rods
Spirilium
A bacterium having a slightly curled or spiral shaped cylinder
Spirochete
Spiral cell containing periplasmic flagella
Branching filaments
Multiple branches off a basic rod structure
Diplococcus
Two cells (side by side)
Streptococcus
Variable number in long chains
Tetrad
Cocci in packets of four
Sarcina
Packet of 8-64 cells
Staph
Irregular clusters
Flagella
Prokaryotic propellers
-Bacterial locomotion
Three distinct parts to flagella
Basal body
Hook
Filament
What are flagella comprised of?
Many proteins
Monotrichous
Single flagellum
Lophotrichous
Small tufts of flagella
Amphitrichous
Flagella at both poles of the cell
Peritrichous
Flagella dispersed randomly over surface of cell
What is chemotaxis?
Bacteria moving in response to chemical signals
How does bacteria move?
Receptors bind extracellular molecules, which triggers flagellum to rotate
Prokaryotic Appendages
Fimbriae
Fimbriae
Used for attachment
Pili
Used for attachment and genetic exchange during conjugation
Glycocalyx
“Protein sugar cell”
What is the glycocalyx composed of?
Polysaccharides, proteins or both
A glycocalyx is used to avoid ______ and for _____
Phagocytosis
Adhesion
Capsule
Bound tightly to cell, visible by negative staining (much more intense than glycocalyx layer)
What does the capsule produce?
A sticky (mucoid) character to colonies
Encapsulated bacterial cells generally have a greater..
Pathogenicity
Streptococcus pneumoniae
Strep species that causes pneumonia, encapsulated
