Exam 3 Flashcards
Diseases are caused by transferable spore like (“seeds”) particles that could transmit infection (who?)
Fracastoro
Father of microbiology that 1st described microbes and invented microscope (who?)
Van Leeuwenhoek
Hand washing prevents childbirth fever (who?)
Semmelweis
Developed antiseptic in surgery (who?)
Lister
Disproved spontaneous generation. Also germ theory
Pasteur
Awarded Nobel prize for work on TB
Koch
Koch’s postulates (4)
Organism must be: 1 - found in all cases 2 - isolated and maint. in pure culture 3 - capable of reproducing infection 4 - retrieved from inoculated animal and recultured
What is unique about prokaryotes?
Do not have membrane bound organelles
Coccus is what shape
Circle/sphere
Bacillus are what shap
Rod
Spirillum are what shape
Spiral
Coccobacillus are what shape
Rod-shaped with round ends
Capsule or slime layer of bacteria is called
Glycocalyx
Gram positive exterior cell structure, color, charge
- Thick peptidoglycan layer surrounding cell membrane
- Stain purple
- Contain technical acids which create negative charge
Gram negative outer cell structure, and color and any other defining features
- Thin peptidoglycan layer surrounds cell membrane
- outer membrane (OM) surrounds peptidoglycan layer
- lipopolysaccharaide (LPS) embedded in OM composed of lipid A and O specific polysaccharide = endotoxins
- lipid A is toxic portion of LPS
- stain pink
Acid fast bacteria cell structure, color:
Cell wall with high lipid content that resists Gram staining
Note: requires unique dyes and heat to stain
Mycobacterium
Genus in which all species are acid-fast
E.g. M. Tuberculosis and M. Leprae
Cells that have NO cell wall exhibit a _______ cell structure because of a high ____________ content
Rigid; sterol
Sterol = waxy solids
Plasma membrane is the site of what activity
Oxidative phosphorylation for ATP synthesis
NOTE: only aerobic species (use O2)
Where are the enzymes that are used for DNA replication in a bacteria?
Cell membrane
What extrudes from cell membrane and acts as receptors in cell metabolism and cell communication?
Proteins
What is a mesome?
Invagination of cytoplasmic membrane that can form into vesicles and plays possible role in cell division
Also increases surface area
What is periplasmic space
Space between inner and outer membranes in Gram negative cells
What structures are the cytoplasm of bacteria?
Nucleiod
Plasmid (DNA)
Ribosomes
Storage granules
Region of bacteria cell containing DNA is called what
Nucleiod
Is there a nuclear membrane?
No
Structure inside the cell that is small extrachromosomal DNA with autonomous replication
Plasmid
Note: plasmids can be transferred between cells during conjugation and often carry antibiotic resistance genes
Organelles composed of ribosomal RNA and protein and are sites of protein synthesis are called what
Ribosomes
External structures of bacteria include
Flagella
Pili (aka fimbriae)
Capsule - slime layer, Glycocalyx
Endospore
What external structure of cell is used for locomotion
Flagella
Counterclockwise rotation of flagella produces ___ motion while clockwise rotation produces ___
Forward; tumbling
What serves as adherence factors on the external structure of a bacteria?
Pili/fimbrae
2 types of pili
1 - sex pili, transfer plasmids
2 - attachment pili, shorter, slow cell to attach to surfaces e.g. host tissue
What is a unique dormant cell type produced by some bacteria in response to adverse conditions?
Endospore
What is sporlation?
When conditions are not favorable cell forms endospore
What is germination
When conditions are favorable, returns to metabolically active cell (vegetative)
Why are endospores important (3)?
1 - allow cell to survive harsh environmental conditions
2 - high virulence factor (resistant to high temps e.g. boiling)
3 - play roll in botulism, tetanus, gangrene, anthrax
Father of taxonomy, classification system with 2 kingdoms (who?)
Linneaus
Classification system with 6 kingdoms (who?)
Woese
3 domain system due to comparison of DNA sequence. Name the 3
Bacteria
Archaea
Eukarya
Bacterial nomenclature:
King Puffs Chest. Oozing Footballs Gambles SavingS
Kingdom Phylum Class Order Family Genus Species Strain
What morphological characteristics (5) serve as identification markers for bacteria?
- Colony characteristics (what does the community look like?)
- Shape of cell
- Capsule? endospore?
- Staining (G+, G- or neither)
- Flagella - movement? (And arrangement of it)
Other than morphological characteristics, what are other ways (7) to tell bacteria apart from each other?
Biochemical testing - test for substrates e.g. sugars
Molecular taxonomy - size of genome, protein similarity, etc
Diagnostic molecular pathology
Polymerase chain reaction
Immunological tests -serotype indicates if it possesses specific set of antigens
Bacteriophage typing
Antibiotic sensitivity testing
An organism’s ______ indicates that it possesses a specific set of antigens
Serotype (immunological testing)
What is bacteriophage typing?
Phage is a virus that infects bacterium. Phages are host specific, so if you figure out what phage can infect a microbe, you can deduce the bacteria involved
Energy source of bacteria?
ATP (adenosine triphosphate)
Catabolism
Breakdown of carb, lipid, protein
Anabolism
Synthesis of cellular components
What metabolism of glucose occurs in the presence or absence of oxygen and 1 molecule of glucose is converted to 2 molecules of pyruvate?
Glycolysis
TCA cycle results in a net gain of:
2 ATP
6 NADH
2 FADH2
Glycolysis results in a net gain of
2 ATP
2 NADH
The final e- acceptor is what?
Oxygen
The use of reducing power of NADH and FADH2 to synth ATP is called
Oxidative phosphorylation
Chemiosmotic theory
ATP is synthesized as a result of proton motive force generated by passing electrons along e- transport chain
Aerobic respiration
Process of transferring e- from NADH and FADH2 to oxygen
Anaerobic respiration
Without O2, e- transferred to an inorganic terminal electron acceptor such as sulfur
Accumulations of highly molecular weight polymers that store glycogen and other energy resources are called
Storage granules
AKA inclusion bodies AKA granular inclusions
Fermentation
Absence of O2, e- transferred to organic terminal electron acceptor
Note: fermentation is used by organisms that can’t respire
What is the ATP yield from catabolism of glucose in aerobic respiration, anaerobic respiration, and fermentation?
Aerobic respiration = 38 ATP
Anaerobic respiration = 30 or less ATP
Fermentation = 2-4 ATP
What temperature do psychrophiles prefer?
-5 to 15˚ C
Psychro means “cold”
What temperature do mesophiles prefer?
25 - 45˚ C
E.g. E. Coli, in other words… they like human body temp which is 37˚C
Human body temp in C
37˚
What temperature do thermophiles prefer?
45 to 70˚C
E.g. hot springs and compost heaps
What temperature do hyperthermophiles prefer?
Over 70˚C
E.g. hot springs, boiling water
Oxygen requirement between obligate aerobes, obligate anaerobes, facultative anaerobes, microaerophiles and aerotolerant anaerobes
Obligate aerobes: need O2 Obligate anaerobes: killed if O2 Facultative anaerobes: better if O2 is around, but survives if not Microaerophiles: require small amt O2 Aerotolerant anaerobes: indifferent