Amino Acids, Proteins and DNA

Question 1

What can zwitterion act as?

Answer 1

acid and base

Question 2

What happens to zwitterion at low pH

Answer 2

NH3+

Question 3

What happens to zwitterion at high pH

Answer 3

COO-

Question 4

carboxylic acid and alcohol gives

Answer 4

ester and water

Question 5

What are proteins?

Answer 5

Polymers made up of combinations of amino acids

Question 6

What is a primary structure of protein?

Answer 6

sequence of amino acids joined together with peptide links

Question 7

What is the condition for hydrolysis (reverse of protein)

Answer 7

6 mol dm-3 HCl
for 24hrs

Question 8

What are the 2 types of secondary protein structure?

Answer 8

alpha-helix and beta-pleated

Question 9

What is the tertiary structure?

Answer 9

Chains folded into a 3D coil with hydrogen and disulfide bonding

Question 10

What happens when 2 cysteine side chain end up near each other

Answer 10

forms sulphur bridge (covalent bond) R-S-S-R

Question 11

What are enzymes?

Answer 11

proteins with tertiary structure that acts as a biological catalyst

Question 12

What happens when enzyme is chiral

Answer 12

Only one enantiomer fits in active site and only catalysed

Question 13

What is the word for enzyme only break down single enantiomer

Answer 13

stereospecific

Question 14

What is DNA and join as

Answer 14

condensation polymer formed from a sugar, a phosphate and a base

join as nucleotide

Question 15

What pairs with Guanine and how many hydrogen bonds

Answer 15

Cytosine
3 Hydrogen bonding

Question 16

What pairs with Adenine and how many hydrogen bonds

Answer 16

Thymine
2 Hydrogen bonding

Question 17

What does cisplatin of Pt(II) do

Answer 17

prevents DNA replication in cancer cells by a ligand substitution with DNA

Question 18

What makes C=O biodegradable?

Answer 18

They are polar so open to attack nucleophile