Microbio Quiz 4

Ames test

Rapid/Simple way to test if a substance if a mutagen

Mutagen

Substance that induces mutations

Carcinogen

A substance that causes cancer

Is a mutagen automatically a carcinogen

No, more tests must be conducted

Prototroph

Synthesizes all of it’s own amino acids

Auxotroph

Cannot synthesize one or more of it’s own amino acids

What bacteria is used in the Ames test?

salmonella typhimurium that us auxotrophic for histidine

Adaptive evolution

A process by which organisms change over time to better adapt to their environment

Biofilm

Bacteria attached to a surface, encased in a 3D extracellular matrix

Planktonic

Free swimming bacteria

Sessile

Cannot move

Biofilm composition

polysaccharides, protein, DNA

Advantages of being in biofilm

Lateral gene transfer, cell to cell communication, protection, trap in nutrients

Are Viruses non-cellular (non-living)

Yes

Are virus genomes double stranded or single stranded

Both

Are viruses obligate intracellular parasites

Yes

Can viruses metabolize outside of a host

No

Viruses are host specific

true

Bacteriophage

A virus that infects bacteria

Plaque

Clear areas in the background of bacterial growth

How are plaques formed

Each plaque forms where 1 phage particle was deposited, then killed by host/bacterial cells after lytic cycles

qRTPCR

quantitative reverse transcriptase PCR

First step of qrtPCR

Extract mRNA

Second Step in qrtPCR

Synthesis of cDNA library from mRNA using reverse transcriptase

third setp of qrtPCR

Fluorescence is measured in real time during PCR

What is the relationship between PCR product and fluorecence?

Fluorescence increases as PCR product doubles during each cycle

Epidemiology

study of public health and it’s applications

What does epidemiology take into account?

distribution and determinants

Who is John Snow

A physician in 1800s London, the founding father of epidemiology

What did John Snow study?

Vibrio cholera

How did John Snow study cholera?

Made a spot map of the cholera outbreak

What symbionts are found in the termite gut?

Eukaryotic, bacterial, and archaeal

What do the symbiotes in the termite gut do?

Help digest cellulose

The eukaryotic symbiotes are:

flagellates, protozoa

The protozoa have their own symbiotes which are

methanogens

What do the methanogens do

Perform methanogenesis: CO2 +4H2 → CH4 + 2H2O

Methanogenesis is inhibited by

O2

Why do methanogens fluoresce under UV

Coenzyme F420, used for carbon metabolism

What color do methanogens fluoresce under UV

green

Fungi

Eukaryotic microbe (yeast, mold)

Protists

eukaryotic microbe (protozoa, algea)

yeast and mold have cell walls that contain

glycogen

Protozoa have cell walls that contain

pellicle

Algea may have cell walls that contain

cellulose or silica

diatoms/dinoflagellates play major roles in performing

photosynthesis