Microbio Chapter 4- Functional anatomy of prokaryotic and eukaryotic cells Flashcards
What are the types of shapes of cells?
Spiral
Bacillus
Coccus
Coccobacillus
Pleomorphic
What are the types of spiral arrangements?
Vibrio
Spirillum
Spriochete
What is an example of a vibrio shaped bacteria?
Vibrio cholerae
What does Vibrio cholerae cause?
Cholera
What is an example of spirochete shaped bacteria?
Treponema pallidum
What does Treponema pallidum cause?
Syphillis
What is an example of bacillus bacteria (rod shaped)?
Bacillus anthracis
What does Bacillus anthracis cause?
Anthrax
What are the arrangements of bacillus?
Single bacillus
Diplobacilli
Streptobacilli
(Rod shaped)
What are the arrangements of coccus?
Diplococci (pair)
Streptococci (chain)
Staphylococci (cluster)
What is an example of diplococci shaped bacteria?
Neisseria gonnorhea
What is an example streptococci shaped bacteria?
Streptococcus pyogenes
What does Streptococcus pyogenes cause?
Strep throat
What is an example of staphylococci shaped bacteria?
Staphylococcus aureus
What does Staphylococcus aureus cause?
Staph infections
MRSA, skin infections
What does pleomorphic mean?
Shape varies
What are the prokaryotic structures external to the cell wall?
Flagella
Axial filament
Glycocalyx
Fimbrae
Pilus
What is a flagella?
Filaments that propel bacteria
Attached to a protein hook
Anchored to wall by basal body
What is it called when there is a flagella on one end?
Monotrichous
What is it called when there are flagella at both ends?
Amphitrichous
What is it called when there is multiple flagella on one end?
Lophotrichous
What is it called when there are flagella distributed over the entire cell?
Peritrichous
What is it called when there are no flagella?
Atrichous
What is an axial filament?
SPIROCHETES ONLY
Bundles of fibrils that spiral around the cell and propel it in a spiral motion (corkscrew)
What is the other name for axial filaments?
Endoflagella
What is the structure of a glycocalyx
Capsule outside of the cell wall made from polysaccharides and polypeptides
What are the functions of the glycocalyx?
- Increase virulence
- Decrease phagocytosis
- Allow bacteria to attach to target environment
What is virulence?
Degree to which a pathogen causes disease
What is a bacteria that has increased virulence?
Streptococcus pneumoniae
What is an example of the glycalyx allowing bacteria to attach to target more easily?
Streptococcus mutans containing a capsule attach to teeth causing tooth decay
What are fimbrae?
Numerous hair like projections on the exterior of a cell
What is the differences between fimbrae and flagella?
Fimbrae are shorter, straighter and thinner than flagella
What is the function of fimbrae?
help attach/adhere to surfaces
What is an example of bacteria with fimbrae?
Neisseria gonorhoeae
What are pili? (pilus)
Pilin protein projections that are involved in motility and DNA transfer
-One or two per cell
Aka Sex pilus
What is the cell wall of prokaryotes made from?
peptidoglycan or murein
What is the peptido portion made from?
Polypeptides and Tetra-peptides (side chains)
What are tetrapeptides?
4 amino acids attached to NAMs
What is the glycol portion made from?
disaccharides related to GLUCOSE
What are the monosaccharides that make up the disaccharide portion?
N-acetylglucosamine (NAG)
N-acetylmuramic acid (NAM)
What do alternating NAMs and NAGs form in peptidoglycan?
A carbohydrate/sugar backbone
What are the two types of bacteria cell walls?
GRAM-positive
GRAM-negative
What are GRAM-positive cell walls made from?
Several layers of PG (more rigid) and teichoic acid
What is Teichoic acid?
Alcohol + phosphate
What alcohols can be present in teichoic acid?
Ribitol - 5 carbons
Glycerol - 3 carbons
What are the two classes of teichoic acids?
Lipoteichoic acid
Wall teichoic acid
What is Lipoteichoic acid?
Spans the PG layer and linked to the plasma membrane
What is wall teichoic acid?
Linked to PG layer
What is the function of teichoic acid?
- Antigenic specificity
- Negatively charged phosphate groups (PO4) regulate movement of positive ions in/out of cell
What is the structure of GRAM-negative cell walls?
One or two layers of peptidoglycan
Outer membrane inside periplasm
What are the 4 layers of the outer membrane of GRAM-negative cell walls?
- Phospholipid bilayer
- Porins (proteins)
- Lipoproteins
- Lipopolysaccharides
What are Porins?
Channels that permit passage of molecules
e.g. Disacharrides, iron and B12
What does a Lipopolysaccharide contain?
Lipids + Carbohydrates
What is the lipid portion of the LPS?
Lipid A
What happens when GRAM-negative cells die?
Lipid A is released acting as an endotoxin
-causes fever, vasodilation, blood clotting, GI tract problems and shock
What is the polysachharide portion of LPS?
O polysaccharide
What is O polysaccharide’s function?
Serves as an antigen
Similar role to Teichoic acid in Gram-positive
What is periplasm?
Periplasmic space
Active area of cell metabolism
Location: Between the outer membrane and the plasma membrane
What are 3 types of atypical cell walls?
Mycobacterium species (Acid-fast cell walls)
Mycoplasma species
Archaea
What do mycobacterium species contain?
Mycolic acid: a waxy lipid bound to PG
What are examples of mycobacterium species?
Mycobacterium tuberculosis (TB)
Mycobacterium leprae (leprosy)
What are mycoplasma?
Lack cell walls
Have sterols in plasma membrane
What are sterols?
Lipids in plasma membrane that help protect from lysis
What is an example of a mycoplasma?
Mycoplasma pneumoniae
What are Archaea?
Have no cell wall or unusual cell wall with no peptidoglycan
Contain pseudomurein/ pseudopeptidoglycan
What is pseudopeptidoglycan/murein?
contains n-acetylalosaminuronic acid instead of NAM
What causes damage to the cell wall of bacteria?
Lysozyme and antibiotics
What is Lysozyme?
A digestive enzyme that catalyzes hydrolysis of the bonds between the sugars in the backbone of peptidoglycan
What happens to GRAM-positive cells when exposed to lysozyme?
Protoplast
- Cell wall is almost completely destroyed leaving just the plasma membrane
What happens to GRAM-negative cells when exposed to lysozyme?
Spheroplast
- cell wall and outer membrane is somewhat destroyed
What causes cell death of protoplasts and spheroplasts?
Osmotic lysis
-Burst in water or dilute salt/sugar solutions
How do antibiotics damage bacteria cell walls?
Inhibits formation of peptido portion of peptidoglycan
-peptide cross bridges can’t form to make a functional cell wall
What antibiotic is gram-positive cell walls more susceptible to?
Penicillin
Why? Bc Gram-negative have fewer peptide cross-bridges
What are endospores?
specialized cells formed from certain nutrient-depleted Gram-positive bacteria
What are two species can have endospores?
Bacillus and Clostridium
What is an example of bacillus containing endospores?
Bacillus antracis
(Causes anthrax)
What are 4 examples of clostridium bacteria containing endospores?
Clostridium tetani (tetanus)
Clostridium perfringens (Gangrene)
Clostridium botulinum (Botulism)
Clostridium difficile (Colitis)
How are endospores formed?
Sporulation
What Gram-negative bacteria can form endospores?
Coxiella burnetti
causes Q-fever