Test 2 Study Guide

Question 1

Hydrogenosome

Answer 1

a membrane-enclosed organelle found in some anaerobic ciliates, flagellates, and fungi. Hydrogenosomes are highly variable organelles that have presumably evolved from mitochondria to produce molecular hydrogen and ATP in anaerobic conditions.

Question 2

Why are cysts always the infective stages for intestinal protozoan parasites?

Answer 2

Cysts of Giardia are present in the feces of infected people. Thus, the infection is spread from person to person by contamination of food with feces, or by direct fecal-oral contamination. Cysts also survive in water, for example in freshwater lakes and streams.

Question 3

Environmental stimuli for encystation of Giardia

Answer 3

Nutrients and cholesterol deprivation

Human, porcine or bovine vile salts

Glycocholate plus either pentadecanoic acid or myristic acid

Sodium glycocholate plus myristic acid and oleic acid

Porcine bile plus lactic acid hermicalcium salt

Question 4

Aerotolerant anaerobes

Answer 4

The aerotolerant anaerobe refers to an organism that is anaerobic as it does not need oxygen to survive and thrive

Question 5

Heteroxenous vs. monoxenous

Answer 5

Heteroxenous: more than one host

Monoxenous: one host

Question 6

Paludism

Answer 6

the state of having symptoms of malaria characterized by high fever and chills.

Question 7

Environmental stimuli for encystation of Entamoeba parasites

Answer 7

a. Hydrogen peroxide plus metal dications
b. Enterobacteria, high CO2 tension and histamine
c. Mg+2, Mn+2, Co+2