Polymers of Life

Question 1

How is high resolution mass spec used to differentiate between compounds with the same Mr?

Answer 1

• High-resolution MS gives M+ peak to several decimal places
• Different compounds have different Mr values in the decimal places
• Atoms of the elements have Ar values that are not exact whole numbers

Question 2

What is another name for a peptide link?

Answer 2

Secondary amide

Question 3

Explain what competitive inhibition is and how it occurs.

Answer 3

it binds to the active site
it has the same/similar: shape/ groups
it cannot be reduced/ cannot react further because no C-C bond
it competes (AW) with succinate for the sites

Question 4

Are amines soluble in water?

Answer 4

Small alkyl group = soluble because the enthalpy change to break H bonds is less than enthalpy change on formation hence favourable
Large alkyl group = insoluble because the enthalpy change to break H bonds is greater than enthalpy change on formation hence not favourable

Question 5

What is the suffix of dicarboxylic acids?

Answer 5

-dioic acid

Question 6

Why can amines act as bases?

Answer 6

The lone pair on the nitrogen accepts a proton by forming a dative covalent bond

Question 7

Amines are derivatives of what compound?

Answer 7

Ammonia

Question 8

What are the three types of amine?

Answer 8

Primary- when one of the Hs on NH3 is replaced by an R group
Secondary- when two of the Hs on NH3 are replaced by an R group
Tertiary- when three of the Hs on NH3 are replaced by an R group

Question 9

Amides are derivative of what homologous series?

Answer 9

Carboxylic acids

Question 10

How are amides formed?

Answer 10

Acyl chloride + ammonia –> primary amide + HCl

Acyl chloride + amine –> secondary amide + HCl

Question 11

Can you make esters from acyl chlorides?

Answer 11

Yes: Acyl chloride + alcohol –> ester + HCl

Question 12

What are the two ways of hydrolysing amides?

Answer 12

Using acidic conditions or basic conditions

Question 13

What is the general formula of acid hydrolysis of primary amides?

Answer 13

Primary amide + water + dilute acid –> carboxylic acid + ammonium salt

Question 14

What is the general formula of alkaline hydrolysis of secondary amides?

Answer 14

Secondary amide + dilute alkali –> amine + carboxylate ion

Question 15

What are the two ways of hydrolysing esters?

Answer 15

Using acidic conditions or basic conditions

Question 16

How are esters hydrolysed by acids?

Answer 16

Reflux with a dilute acid, like HCl. The products are an alcohol and a carboxylic acid. This a reversible reaction

Question 17

How are esters hydrolysed under alkaline conditions?

Answer 17

Reflux with a dilute alkaline, like NaOH. The products are an alcohol and a carboxylate ion.

Question 18

Two types of polymers?

Answer 18

Addition polymers and condensation polymers