Flashcards in Week 3 - Bacterial Growth and Microbe Structure -Ziegler Deck (55)
Outline the 4 steps of bacterial fission:
-replication of DNA
-generate a cross wall
What is the difference between doubling time and generation time?
They are both the same thing. Amount of time required to double the number of cells in culture is the generation time. And the time for one cell to become two is the doubling time.
Stages of the cell growth curve?
Lag phase: bacteria adapt to new environment
Log Phase: exponential growth, doubles fast
Stationary: nutrients exhausted and toxic products build up. Bacteria numbers stay constant
Death: Bacteria die of toxicity (not always)
Why do cells replicate slower in an abscess?
It is an area of low oxygen. So bacteria are only going to be using anaerobic growth. This is less efficient and consequently slower.
How are CFU's used to determine bacterial concentration?
Concentration is diluted and plated onto media
Each colony will then represent one bacteria from the original culture
REMEMBER: this will only represent viable bacteria
What are fermentation end products of Streptococcus, Lactobacillus, and Bacillus?
What are fermentation end products of Saccharomyces (yeast)?
Ethanol and CO2
What are fermentation end products of Propionibacterium?
Propionic Acid, Acetic Acid, CO2, and H2
What are fermentation end products of Clostridium?
Butyric Acid, Butanol, Acetone, Isopropyl Alcohol, and CO2
What are fermentation end products of Escherichia and Salmonella?
Ethanol, Lactic Acid, Succinic Acid, Acetic Acid, CO2, and H2
What are fermentation end products of Enterobacter?
Ethanol, Lactic ACid, Formic Acid, Butanediol, Acetoin, CO2, and H2
List a few things you should keep in bacterial growth media
The growth media must contain: carbon, nitrogen, sulfur, phosphorus, calcium, magnesium, potassium, iron, and other minerals in small amounts.
Iron is NOT required for the growth of Borrelia species (in other words, there are often exceptions).
What is a heterotroph?
Requires preformed organic compounds (sugars AA's, and vitamins)
What is an autotroph?
Can synthesize everything is needs from inorganic compounds like CO2
Obligate intracellular pathogen - requires organic compounds from host (viruses)
What carrier proteins help bacteria uptake important nutrients?
What does it mean to be an obligate aerobe?
Must have O2 for growth! No fermentation allowed!
What does it mean to be an obligate anaerobe?
These organisms are actually killed by O2. Use fermentation!
What does it mean to be a facultative anaerobe?
Can grow with or without O2
Why on earth is superoxide dismutase an important enzyme?
it gets ride of superoxide radicals, which is dang important for any aerobic organisms! Radicals cause a big ruckus if they are left sitting around.
4 differnt kinds of microbes are?
Why are ribosomes a good target for antibiotics?
Ribosomes are made differently between Euk and Prok
(it would be great if someone had more clarification for this one)
What is the shape of bacillus bacteria?
2 bacilli together? Chains? X,V,Y figures?
Shaped like rods
2 bacilli= diplobacti
Chains = streptobacilli
X,V,Y figures = palisades
What are the spherical bacteria called?
Spirochetes have what conformation?
FLEXIBLE undulating corkscrew
What kind of bacteria have a RIGID corkscrew shape?
What is the mesosome?
Chromosomal DNA attached to inner bacterial membrane near site of bacterial division
(wikipedia says this is hocus pocus?)
What kind of info usually on plasmids?
resistance to antibiotics and stuff
Why should a doctor care about flagella?
They can be targets for antibiotic therapies!