Polymers, amino acids, proteins and DNA

Question 1

What is an addition polymer?

Answer 1

A long chain formed from many monomers and no other product is formed

Question 2

What are the two main types of condensation polymers?

Answer 2

Polyesters
Polyamides

Question 3

What are polyesters?

Answer 3

Formed from carboxylic acids and alcohols
Have ester links

Question 4

What are polyamides?

Answer 4

Formed from carboxylic acids and amines

Question 5

Example of condensation polymers (3)

Answer 5

Terylene
Nylon
Kevlar

Question 6

What type of condensation polymer is terylene?

Answer 6

Polyester

Question 7

What is terylene made up of?

Answer 7

ethane-1,2-diol
benzene-1,4-dicarboxylic acid

Question 8

What are the uses of terylene? (2)

Answer 8

Used to make carpets, clothing
Heat treated polyesters used for drinks bottles

Question 9

What functional group is formed when an amine and carboxylic acid react?

Answer 9

Amide

Question 10

What type of condensation polymer is nylon?

Answer 10

Polyamide

Question 11

What type of condensation polymer is kevlar?

Answer 11

Polyamide

Question 12

Monomers of nylon 6,6

Answer 12

1,6-diaminohexane
hexane-1,6-dicarboxylic acid

Question 13

Monomers of kevlar

Answer 13

benzene-1,4-diamine
benzene-1,4-dicarboxylic acid

Question 14

Properties of nylon (2)

Answer 14

Elastic, strong abrasion resistant

Question 15

Uses of nylon (1)

Answer 15

Used as fibres in clothing

Question 16

Properties of Kevlar (3)

Answer 16

Strong, light and heat resistant

Question 17

Uses of Kevlar (2)

Answer 17

Used in the manufacture of body armour and crash helmets

Question 18

Why are addition polymers non-biodegradable? (2)

Answer 18

Non polar C-C bonds so they cannot by hydrolysed
Therefore, they cannot be broken down by nucleophiles

Question 19

Why are condensation polymers biodegradable? (2)

Answer 19

Can be hydrolysed
The delta positive C of the polar C=O can be attacked by nucleophiles

Question 20

Why do amino acids have high melting points?

Answer 20

Due to the strong electrostatic attractions between zwitterion

Question 21

Under what conditions can condensation polymers be hydrolysed?

Answer 21

Acidic or basic conditions

Question 22

What happens to amino acids in acidic conditions?

Answer 22

Get protonated

Question 23

What happens to amino acids in alkaline conditions?

Answer 23

Get deprotonated

Question 24

When linking amino acids, how must they be written?

Answer 24

NH2 group on the left and COOH on the right

Question 25

Hydrolysis of peptides require what conditions

Answer 25

Boil for 24 hours 6 moldm-3 HCl catalyst

Question 26

Why do hydrogen bonds form in secondary structures of amino acids?

Answer 26

Electron deficient H Attracts the lone pair on the O

Question 27

Two cysteine amino acids form what kind of bonds?

Answer 27

Disulphide bonds

Question 28

To form a disulphide bond, what position must the two cysteine molecules be in?

Answer 28

Parallel to each other

Question 29

What kind of proteins are enzymes?

Answer 29

Globular

Question 30

One property of enzymes

Answer 30

Stereospecific

Question 31

How does drug development take place using enzyme inhibition?

Answer 31

An undesirable biological process occurs which is catalysed by an enzyme A computer is used to determine the shape of the active site and design another molecule which will fit into the active site. This must be the correct enantiomer This new molecule is called the inhibitor

Question 32

What is the sugar called in DNA?

Answer 32

2-deoxyribose

Question 33

How does cisplatin work? (2)

Answer 33

Binds to the DNA in cancerous cells and a bond forms between platinum and nitrogen atom on guanine (in a ligand replacement reaction) Prevents the DNA from unwinding and so the cancer cells cannot replicate

Question 34

Things to consider when using cisplatin (4)

Answer 34

Cis-platin will also bind to the DNA in healthy cells. This can cause unwanted side effects. The cis-platin drug can be targeted straight to the cancer cells to reduce the effect on healthy tissue. It can also be used in minimal amounts