Polymers and Life

Question 1

Describe carboxylic acids.

Answer 1

Strong enough to form salts with bases. React with carbonates to form water and carbon dioxide.

Question 2

Describe phenols.

Answer 2

Form salts with metals in a redox reaction.

Question 3

Describe esters.

Answer 3

Produced via condensation reactions. Reversed by ester hydrolysis.

Question 4

Which reaction produces polyesters?

Answer 4

Addition reactions.

Question 5

Describe amines.

Answer 5

Form hydrogen bonds with water. Amines with small groups are soluble. The lone pair can be used in dative covalent bonding.

Question 6

How is nylon named?

Answer 6

According to the number of carbons in monomers.

Question 7

What is produced when an ester is hydrolysed?

Answer 7

Carboxylic acid + alcohol.

Question 8

What is produced when an ester is hydrolysed by an alkali?

Answer 8

Produces a carboxylate salt, C2H5COO-.

Question 9

What is produced in the acid hydrolysis of an amide?

Answer 9

A carboxylic acid and an ammonium ion. A secondary amide produces a carboxylic acid and an amine salt.

Question 10

What is produced in the alkaline hydrolysis of an amide?

Answer 10

A carboxylate ion and an amine.

Question 11

Describe an amino acid and its function as a zwitterion.

Answer 11

Bifunctional compound. In alkaline conditions, COO- ion. In acidic conditions, NH3+ ion.
Acts as a buffer.
Found at the anode with an increase in pH. Carboxylic acid is found at the cathode with a decrease in pH.

Question 12

Describe adenine and guanine.

Answer 12

Purines, double ringed.

Question 13

Describe thymine and cytosine.

Answer 13

Pyramidines, single ringed.

Question 14

How are adenine and thymine joined?

Answer 14

Two hydrogen bonds.

Question 15

How are guanine and cytosine joined?

Answer 15

Three hydrogen bonds.

Question 16

Describe optical isomerism.

Answer 16

Non-superimposable. Chiral carbon. Enantiomers.

Question 17

Describe the use of enzymes in diabetes.

Answer 17

Reagent strips containing glucose oxidase, indicator, peroxidase and a buffer.

Question 18

What is the rate determining step of an enzyme-catalysed reaction?

Answer 18

EP->E+P

Zero order.

Question 19

Describe a competitive inhibitor.

Answer 19

A molecule which fits into the active site, but does not catalyse the reaction.

Question 20

Describe pharmacophores.

Answer 20

For example: Captropril fits into the active site of ACE, preventing catalysis. This is a pharmacophore.
Pharmacophores can be modified by changing functional groups, which increases effectiveness or reduces side effects. They interact with receptor sites.

Question 21

Describe NMR.

Answer 21

Odd numbers of subatomic particles cause nuclei to behave like magnets. Isotopic nuclei are charged and have a spin which creates a magnetic field. Energy can be used to change the spins. Nuclei oppose or line up with the magnetic field. Nuclei opposing have higher energies. Measured by the TMS peak.

Question 22

Describe 13C NMR.

Answer 22

Measures the number of different carbons, the number of carbon environments and the relative ratio.

Question 23

Describe 1H NMR.

Answer 23

Measures the number of hydrogen environments, the number of hydrogens in each environment, the nature of the environment, and the number of hydrogens on adjacent carbons (n+1, where n is the number of subpeaks).