Microbiology Unit 3 Flashcards
What substance is found the cell walls of bacteria and only bacteria?
Peptidoglycan
How does penicillin kill bacteria?
Interferes with peptidoglycan in bacterial cells walls, inhibiting cell wall formation
What cell membrane feature can only be found in archaeans?
Phospholipid monolayer
(not found in all archaeans)
What are the three parts of the flagella
Filament
Hook
Basal Body (Anchor)
Monotrichous
Lophotrichous
Ambitrichous
Peritrichous
Single flagellum coming from one end
Multiple flagella coming from one end
Multiple flagella coming from both ends
Flagella coming from all over cell
How does a bacterium move when its flagella counterclockwise?
Clockwise
Smooth linear movement - run
Tumble
Spirochet / Periplasmic Flagella
Filament that wraps around the body of a bacterium to provide a corkscrew movement
Fimbrae
Thin hairlike appendages on the outside of a bacterium
Used for adhesion
Conjugation
Exchange of genetic information from one bacterium to another
Glycocalyx
(And 2 types)
Coating of molecules outside cell wall of bacteria
Protect from dehydration, nutrient loss, and phagocytosis
Allows adhesion to form biofilm
Slime layer
Capsule
Appendages
External filaments on a bacterium
Flagella, fimbriae, pili
Pili
Rigid tubular appendage made of pilin
Allows for conjugation, can adhere to surfaces
Which bacteria have pili?
Gram-negative
Biofilm
A colony of microbes living in a complex mass on a surface (slimy layer)
What is the defining feature of gram-positive bacteria?
Thick cell wall composed of peptidoglycan, teichoic acid, and lipoteichoic acid
What is the defining feature of gram-negative bacteria?
Thin peptidoglycan layer between two cell membranes
Outer layer consists of lipopolysaccharides and porins
Periplasmic Space
Space between the cell membrane and cell wall
Mycoplasma
Bacterium w/ no cell wall
2 Types of bacteria w/ atypical cell wall
Mycobacterium
Nocardia
Plasmid
Free small, circular, double-stranded DNA used to introduce new genetic material in both conjugation and genetic engineering
Which type of ribosome is found in both prokaryotic and eukaryotic cells?
70s
What purpose do bacteria use inclusion bodies for?
Storage
Endospores
A hard outer cell some gram-positive cells when exposed to harsh condition
Allows bacterium to enter suspended animation
Can live 250 million years
Vegetative Cell
A metabolically active cell
Sporulation
Formation of endospores
Germination
Return of an endospore to vegetative growth
What is the most reliable means to destroy endospores?
Pressurized steam at 120 degrees C for 20-30 minutes
Coccus
Spherical
Bacillus
Coccobacillus
Vibrio
Rod-Shaped
Short, plump rod
Gently curved rod
Spirillum
Spriochete
Helical, rigid
More flexible helix
Pleomorphism
Variation in cell shape and size within species due to environmental or genetic factors
Sarcina
Cubical colonies of coccal bacteria
Pallisade
Hinged fence-like stake structure of bacillic bacterial colony
Psychrophile
Organism whose optimum temperature is below 15 degrees C
Can continue producing at 0 degrees C
Mesophile
Organism whose optimum temperature is between 20 and 40 degrees C
Thermophile
Organism whose optimum temperature is above 45 degrees C
What temperature adaption group are most human pathogens in?
Mesophile
Facultative Anaerobe
An organism that uses oxygen but can grow without oxygen
Microaerophile
An organism that can survive with small amounts of oxygen
Aerotolerant anaerobe
An organism that does not use oxygen but can survive in its presence
Capnophile
An organism that prefers CO2 levels higher than in normal atmosphere
Syntrophy
Nonsymbiotic relationship where organisms cooperate and share resources
Amensalism
Nonsymbiotic relationship where one organism inhibits or destroys another
Nonsymbiosis
Relationship between organisms that is not required for either organism’s survival
Fermentation
The least efficient means of ATP production, consists only of glycolysis
What is the number of ATP molecules produced per cycle of aerobic respiration?
Anaerobic respiration?
Fermentation?
38
Varies by organism
2
What are the 4 stages of aerobic respiration?
- Glycolysis
- Link / transition step
- Krebs cycle
- Electron transport chain
Glycolysis
Breakdown of glucose (C6) into
2 Pyruvates (C3) and NADH
NADH
A high-energy electron carrier
Takes electrons to electron transport chain
Link / transition phase
Minor changes to pyruvate and NADH, process moves to mitochondira
Krebs Cycle
Changes the pyruvate into CO2, more NADH and FADH2 are also produced
Electron Transport Chain
Electron carriers (NADH and FADH2) send electrons down a serries of membranes, producing energy and releasing electrons to make ATP
How many ATP molecules are made from one NADH?
One FADH2?
3/NADH
2/FADH2
Which stage of Aerobic respiration occurs in the cytoplasm?
Glycolysis
What oxygen alternatives are used in anaerobic respiration?
Nitrate (NO3-) and Nitrite (NO2-)
What are the two types of fermentation?
- Lactic acid fermentation (produces lactic acid)
- Alcohol Fermentation (Produces ETOH and CO2)
What form of respiration do prokaryotes use?
Fermentation
What are the two stages of Oxygenic photosynthesis?
Light reaction (Production of ATP and NADPH)
Calvin Reaction (Conversion of CO2, ATP and NADPH into sugar)
(Order of these reactions varies)
Why does anoxygenic photosynthesis not produce O2?
what 2 pigments are used in anoxygenic photosynthesis?
H2O does not act as an electron source
Bacteriochlorophyll or archaerhodopsin are the main pigment
Halophile
phototrophic archeans
“Salt-Lover”
Lipopolysaccharides and porin are important components of what type of bacteria?
Gram-negative
What two structures make up the cell envelope?
Cell membrane and cell wall
