Question

question 19 (1 point) ✓ saved
when a reaction generates heat, the reaction is termed endergonic.
true
false
question 20 (1 point) ✓ saved
mycoplasmas lack a cell wall. their cell membrane is stabilized by __________ and is resistant to lysis.
testosterone
sterols
teichoic acid
porin
question 21 (1 point) ✓ saved
the hanging drop preparation is useful when observing biochemical reactions
true
false
question 22 (1 point) ✓ saved
the disease bovine spongiform encephalopathy is also known as
kuru.
scrapie.
cruetzfeldt - jakob disease.
mad cow disease.

Explanation:

• Question 19: An exergonic reaction releases energy (like heat), while an endergonic reaction absorbs energy. So, the statement is false.
• Question 20: Mycoplasmas lack a cell wall. Sterols in their cell membrane help stabilize it and resist lysis. Testosterone is a hormone in animals, teichoic acid is in some bacterial cell walls, and porin is a protein in outer membranes of some bacteria.
• Question 21: The hanging drop preparation is useful for observing motility of microorganisms, not biochemical reactions.
• Question 22: Bovine spongiform encephalopathy is commonly known as mad cow disease. Kuru is a human prion disease, scrapie is in sheep, and Creutzfeldt - Jakob disease is also a human prion disease.

Answer:

• Question 19: False
• Question 20: sterols
• Question 21: False
• Question 22: mad cow disease