Macromolecules and pH

Which of the following compounds is most likely to be part of living organisms?

• CsI

• MoCl₂

• BF₃

• C₆H₁₂O₆

Which of the following best describes the composition of a nucleotide?

• a five-carbon sugar attached to a phosphate group and a nitrogenous base

• a carbon atom join to hydrogen and three functional groups

• a pair of six-carbon rings attached to each other

• a chain of carbon atoms with a carboxyl group bonded to one end

Human blood pH is slightly basic. Which of the following would best fit the description of normal blood pH range?

• 6.5 to 6.9

• 10.1 to 10.9

• 13.5 to 14.0

• 7.3 to 7.4

A solution that has a balance, or equal amounts, of H+ and OH- ions would be considered a:

• buffer

• neutral

• acid

• base

A substance found in most living organisms, that helps maintain homeostasis by resisting changes in pH is called a(n):

• base

• buffer

• acid

• neutral