Ch. 4 - Functional Anatomy of Prokaryotic and Eukaryotic Cells Flashcards
Why is it important to know the average side of bacteria?
For identification (naming)
- genus, species
What unit of measurement is used for bacteria?
microns/micrometer
µm
Majority of bacteria are ___________, but some bacteria are _____________.
monomorphic
pleomorphic
Compare and contrast monomorphic from pleomorphic
monomorphic: one shape is present
pleomorphic: many shapes are present
What are some reasons as to why a culture may be pleomorphic?
- mixes culture of bacteria
- may be contaminated
Name the three basic shapes of prokaryotes
Coccus
Bacillus
- Coccobacillus
Spiral
- Vibrio
- Spirillum
- Spirochete
Describe the shape of:
Coccus
Bacillus
Coccobacillus
Vibrio
coccus: spherical/round
bacillus: rod-shaped/rectangular
coccobacillus: oval-shaped (still considered rod-shaped)
vibrio: comma-shaped
What shape of prokaryotic cells are capable of motility?
spiral (vibrio, spirillum, spirochete)
Compare spirilla/spirillum from spirochetes
Draw a picture of these (optional)
(include cell description, how cells move)
Spirilla/spirillum
- rigid cells
- short/thick cells
- loosely coiled cells
- cells move via flagella
Spirochetes
- flexible cells
- longer/thin cells
- tightly coiled cells
- cells move via endoflagella
Name the different cell arrangement of prokaryotic cells
Pairs: diplo-
Clusters: staphylo-
Chains: strepto-
EXCLUSIVE TO COCCI:
Groups of four (2x2): tetrads
Cube-like groups of eight (2x2x2): sarcinae (two tetrads stacked)
Be able to draw the arrangement and shape of specifically named bacteria (Ex: How would staphylococcus vs. streptobacillus look like?)
DRAW:
diplococci
diplobacilli
staphylococci
streptococci
streptobacilli
tetrads
sarcinae
refer to slide 5 of chapter 4
Be able to label the different prokaryotic cell structures.
Refer to blank PDF sheet provided by professor
Describe glycocalyx (in Prokaryotes)
Include: Location, characteristics, composition, function, and types/examples
Location
Layer external to cw
Characteristics
- Optional: may/may not be present
- Viscous (thick) & gelatinous
Composition
- Polysaccharides (carbs)
OR
- Polypeptides (protein)
Function(s)
Glycocalyx - Capsule (carb):
- Bacterium easily attaches to host tissue bc of sticky capsule (bc its sugar) = DANGEROUS
- Makes bacterium look bigger = escape phagocytosis
- EX OF ENCAPSULATED BACT:
Streptococcus mutans (mouth/teeth = cavities)
Streptococcus pneumoniae (largest capsule)
Types/Examples
- Capsule (carbs): thick, organized, attached to cw
- Slime layer (protein): thin, unorganized, loosely attached to cw
Draw the difference between a prokaryote cell with a glycocalyx capsule and one with a slime layer
Should have drawn capsule as thick, organized and tightly attached to cw
should have drawn slime layer as thin, unorganized, and loosely attached to cell wall
Describe Flagella/Flagellum (in Prokaryotes)
Include: Location, characteristics, composition, function
Location
- External to cell
- Found in some
bacilli/bacillus sprilla/spirillum
Characteristics
- Optional: may/may not be present
- Long, filamentous appendages
- Various arrangements
Composition
- Flagellin (protein) -> filaments -> flagellum
- Three parts: filament, hook, basal body
Function(s)
Flagella
- Move bacteria: locate nutrient source, escape phagocytosis
Flagellin Protein
- Act as “H antigens” (surface markers) to distinguish among different subspecies/strains of bacteria
Ex: E. coli O157:H7
Types/Examples
N/A
Is this bacteria capable of motility:
E. coli O157:H7
If yes, how are you able to tell?
Yes, because it has an H antigen. H antigens are found in flagellin protein which make up a flagellum. Flagellums function to move bacteria
Name the three parts to flagellum. Briefly describe them
If possible, draw it out and label the parts.
Filament: outermost region
Hook: attaches to filament to basal body
Basal body: anchors flagellum
Describe Axial Filaments/Endoflagella (in Prokaryotes)
Include: Location, characteristics, composition, function
Location
- Internal to cell (intracellular)
- In between outer mem. of cell wall and cell membrane
- Found in spirochetes
Characteristics
- Optional: may/may not be present
- Anchored at one end
Composition
- Proteins
Function(s)
Rotation of axial filament/endoflagella allows cell to move in corkscrew/sprial motion
Types/Examples
N/A
Describe Fimbriae (in Prokaryotes)
Include: Location, characteristics, composition, function
Location
- External to cell
Characteristics
- Hair-like appendages
Composition
- Proteins
Function(s)
- Allows for attachment
Types/Examples
N/A
Describe Pili/Pilus (in Prokaryotes)
Include: Location, composition, function, and types/examples
Location
- External to cell
Characteristics
N/A
Composition
- Proteins
Function(s)
- Allows “twitching” motility
- DNA transfer
Types/Examples
- Conjugation pilus (DNA transfer): Transfers DNA from donor cell to recipient cell, now making the recipient cell different
Describe Cell Wall (in Prokaryotes)
Include: Location, characteristics, composition, function
Location
- Outermost layer (if no glycocalyx present)
Characteristics
- Most bacteria have cw
- Varying amounts of peptidoglycan
- More peptidoglycan = thick; gram-positive bact. (violet)
- Less peptidoglycan = thin; gram-negative bact. (pink/red)
Composition
- Peptidoglycan (rows of carbs connected to proteins)
Function(s)
- Prevents osmotic lysis (cell rupturing)
- Gives structure to bacteria
- protects cell membrane
Types/Examples
N/A
Compare Gram-Negative Bacteria from Gram-Positive Bacteria
(layer, acid, outermembrane, sensitivity)
If possible, include a drawing showing the difference
Gram-Negative Bacteria:
Thin peptidoglycan layer
No teichoic acids
Has outermembrane with LPS (lipopolysachharide)
Resistant to PCN (penicillin)
Gram-Positive Bacteria
Thick peptidoglycan layer
Has teichoic acids
No outermembrane
Sensitive to PCN (penicillin)
What is the major component to the outer membrane of Gram-Negative Bacteria cell wall?
LPS (lipopolysachharide)
What is LPS (lipopolysachharide) made of?
What type of bacteria contain LPS?
Name the three components of LPS and their function
Draw and label these components
lipids and carbs
gram negative bacteria
3 components:
- Lipid A: functions as toxin
- Core polysachharide: Joins lipid A and O polysachharide
- O polysachharide: Functions as antigen (surface marker) to help distinguish between different strains (there are diff. types of O polysachharides)