3.3.13 - Amino acids, proteins and DNA

Question 1

How is a protein formed?

Answer 1

2 amino acids combine via condensation polymerisation

Question 2

What two functional groups does an amino acid have?

Answer 2

NH2 + COOH

Question 3

State the zwitterion for acidic conditons

Answer 3

NH3+

Question 4

State the zwitterion for basic conditons

Answer 4

COO-

Question 5

How can you separate amino acids?

Answer 5

TLC + UV light

Question 6

How do you break up a protein into its individual amino acids? (3)

Answer 6

1. Add aqueous 6 moldm-3 HCl
2. Heat
3. Under reflux

Question 7

What are the two types of bonding in tertiary structures?

Answer 7

1. Hydrogen bonding
2. Disulfide bridges

Question 8

What are nucleotides made of? (3)

Answer 8

• Phosphate group
• Pentose sugar
• Nitrogenous base

Question 9

What are the two base pairings?

Answer 9

1. AT
2. CG

Question 10

Which base pairings forms 3 hydrogen bonds?

Answer 10

CG

Question 11

What is the structure of cisplatin?

Answer 11

• 2 NH3 groups
• 2 Cl groups

Question 12

How is cisplatin able to cure cancer?

Answer 12

• Bonds to two adjacent guanine bases
• Causes kink in DNA

Question 13

How do two nucleotides join together? (2)

Answer 13

1. Condensation reaction
2. Phosphodiester bond forms

Hydrogens on phosphate removed, OH removed from nucleotide

Question 14

How does the bond between a base and a central metal ion form in DNA?

Answer 14

Coordinate bond using a nitrogen (with H bonded to it) atom

Question 15

Why can urea seperate DNA?

Answer 15

• Amino groups in urea
• H bonds will form between the urea and the DNA strands.

Question 16

What determines the strength of interaction between two cysteine R groups and a serine and aspartic R group?

Answer 16

Disulfide bridges are stronger than hydrogen bonds