Section 24.3 (Exam 1) Flashcards
Ecological Communities Depend on Prokaryotes
___________ usually live in communities of many different microbial species.
Prokaryotes
What are biofilms?
A gel-like polysaccharide matrix that traps other cells; forms when cells contact a solid surface.
Human health depends in part on the health of the communities of what that live in our body? What is this called?
Communities of bacteria. Microbiome.
Babies born by C-section or bottle-fed artificial formula have higher incidences of what? Why?
Auto-immune disease. Because they never acquired the proper bacteria, and don’t have a healthy microbiome.
How do you get vitamins B12 and K?
They are absorbed by your gut microbiome.
The biofilm that lines human intestines functions like a specialized “tissue” in what way?
By facilitating nutrient uptake.
Name Koch’s Postulates to establish that a specific organism causes a specific disease.
Microorganism is found in afflicted individual.
Microorganism is isolated and grown in PURE culture.
A sample of the pure culture can infect a healthy individual successfully.
The victim yields a PURE culture.
For an organism to become a pathogen it must:
Arrive at the body surface of a host.
Enter the host’s body.
Evade the host’s defenses.
Multiply inside the host.
Infect a new host.
What is a pathogen’s invasiveness?
Its ability to multiply.
What is a pathogen’s toxigenicity?
Its ability to produce toxins.
Diptheria bacteria has low or high toxigenicity and low or high invasiveness?
high toxigenicity; low invasiveness
Bacillus anthracis (anthrax bacteria) has low or high toxigenicity and low or high invasiveness?
low toxigenicity; high invasiveness
Endotoxins are released when Gram-___________ bacteria are lysed.
Gram-negative
Endotoxins are ___________________________ from the outer membrane.
lipopolysaccharides
Are endotoxins fatal?
Rarely.
