October 28

Question 1

cAMP

Answer 1

Regulatory nucleotide

Key molecule in many metabolic control systems

Question 2

Regulation of the lac operon in E. coli

Answer 2

*Positive control

*glucose must be absent, and lactose must be present

1. Repressor prevents RNA pol from binding to the promotor.
2. Allactose acts as an inducer that binds to the lactose repressor, which induces a change in the active site and the repressor falls off.
3. Glucose inhibits synthesis of cAMP, and stimulates its transport out of the cell. Without glucose, cAMP accumulates in the cell and binds to the allosteric site of CRP, causing a conformation change in the active site as well as the protein, and CRP binds to the activator-binding site.
4. RNA pol then binds to the protein and DNA
5. Transcription occurs.

Question 3

Global Control

Answer 3

Many enzymes are under control of catabolic operons (lactose, maltose, and glucose)

Flagellar genes are also controlled by catabolite repression

Question 4

Disinfectant

Answer 4

Removes microbes from inanimate objects

Question 5

Fomite

Answer 5

Inanimate objects which can transport pathogens

Question 6

Antiseptic

Answer 6

Controlling microbial growth on tissues

Question 7

Degerming

Answer 7

Removal by physical act of scrubbing to remove microbes, usually more important than the chemical involved

Question 8

-static, -stasis

Answer 8

slow or halt growth

Question 9

-cide, -cidal

Answer 9

Kill microbes

Question 10

Efficacy of Antimicrobial Methods

Answer 10

How well methods control microbial death, to evaluate efficacy look at microbial death rate, usually constant over time.

Question 11

Effectiveness of Germicides

Answer 11

1. High level: Kills pretty much all pathogens
2. Intermediate level: kills fungal spores, cysts, viruses, and gram positive and negative bacteria
3. Low level: Kill vegetative cells, fungus, trophozoites, and some viruses