BGM1002/L12 Phosphorus

Question 1

Name the 6 most abundant elements in the body.

Answer 1

C, O, H, N, Ca, P

Question 2

What form does almost all organic phosphorus take in biological systems?

Answer 2

Phosphoric acid/phosphate

Question 3

How are electrons positioned in phosphate?

Answer 3

Dissociated throughout

Question 4

Why is electron dissociation important?

Answer 4

For stability and function of phosphorus

Question 5

What molecule does phosphorus exist as in bones?

Answer 5

Insoluble mineral hydroxylpatite
Ca5(PO4)2(OH)

Question 6

What are the three phosphate molecules in ATP?

Answer 6

Alpha, beta, gamma

Question 7

As pH increases, what happens to phosphoric acid?

Answer 7

Protons are released

Question 8

What is the Henderson-Hasselbach equation?

Answer 8

pH = pK + log[A-]/[HA]

Question 9

What type of reaction is formation of a phosphodiester bond?

Answer 9

SN2
Substitution, nucleophilic, bimolecular

Question 10

How is an anhydride formed?

Answer 10

Condensation of two acid molecules

Question 11

What type of bonds exist between phosphates in ATP?

Answer 11

Phosphoanhydride

Question 12

What are phosphoanhydride bonds sometimes called in ATP?

Answer 12

High energy bonds

Question 13

Give 2 explanations for high free energy of ATP hydrolysis.

Answer 13

Electrostatic repulsion
Resonance stabilisation
Solvation/hydration of products