Phosphorus Containing Compounds

Question 1

What is phosphoric acid?

Answer 1

inorganic acid with the potential to donate three protons

Question 2

What does it mean to be inorganic?

Answer 2

does not contain any carbon atoms

Question 3

In physiological pH, what form does phosphoric acid generally exist in?

Answer 3

significantly dissociated, largely in anionic form

Question 4

What is the most common phosphoric acid found in the human body?

Answer 4

hydrogen phosphate HPO4(2-)

Question 5

What is the second most common phosphoric acid found in the human body?

Answer 5

dihydrogen phosphate (H2PO4-)

Question 6

What is phosphate also known as?

Answer 6

orthophosphate

Question 7

What is the linkage that binds two orthophosphates together?

Answer 7

anhydride linkage

Question 8

What is a pyrophosphate?

Answer 8

two orthophosphates bound together

Question 9

Is hydrolysis of pyrophosphate thermodynamically favorable or unfavorable?

Answer 9

favorable

Question 10

What are the three reasons that phosphate anhydride bonds store so much energy?

Answer 10

1. when phosphates are linked together, their negative charges repel each other strongly
2. orthophosphate has more resonance forms and thus a lower free energy than linked phosphates
3. orthophosphate has a more favorable interaction with water than linked phosphates

Question 11

What are nucleotides?

Answer 11

building blocks of nucleic acids (RNA and DNA)

Question 12

What do nucleotides consist of?

Answer 12

ribose or deoxyribose sugar
purine or pyrimidine base
1, 2, or 3 phosphate units joined together

Question 13

What is the universal energy storage molecule?

Answer 13

ATP

Question 14

What are the roles of ATP?

Answer 14

cellular metabolism
RNA precursor

Question 15

What are other phosphate energy carriers and what are their functions?

Answer 15

GTP = protein synthesis
UTP = activate glucose-1-P