Types of Molecules

Question 1

Which group make carbohydrates soluble in water?

Answer 1

Hydroxyl groups

Question 2

Purines

Answer 2

• Adenine

- Guanine

Question 3

Pyrimidines

Answer 3

• Cytosine

- Thymine

Question 4

3 hydrogen bonds

Answer 4

Guanine and cytosine

Question 5

2 hydrogen bonds

Answer 5

Adenine and thymine

Question 6

Consist of carbon and hydrogen chain with acidic carboxyl group

Answer 6

Fatty acids

Question 7

• Present in the blood
• Synthesized in the liver
• Stored in adipose tissue

Answer 7

Triglycerides

Question 8

• 3rd hydroxyl group is linked to phosphate
• Small polar or ionised nitrogen-containing molecule is attached to phosphate
• Amphipathic

Answer 8

Phospholipids

Question 9

• 4 interconnected rings of carbon atoms

- Not water soluble

Answer 9

Steroids

Question 10

Amino acid subunits

Answer 10

• Contains amino, carboxyl and carbon group
• A peptide bond forms between carboxyl group and amino group by dehydration
• Essential amino acids must be obtained in diet

Question 11

Primary structure

Answer 11

Determined by polypeptide chain

Question 12

• Attractions between regions along polypeptide chain
• Hydrogen bonds between peptide bonds force the chain into alpha-helix
• When regions of chain run parallel to each other, hydrogen bonds between peptide bonds from beta-pleated sheet
• Allow protein to anchor itself into a lipid bilayer

Answer 12

Secondary structure

Question 13

• Associations between additional amino acid side chains
• Fold polypeptide into 3D conformation
• 5 factors
  * Hydrogen bonds
  * Ionic bonds
  * Attraction between nonpolar regions
  * Covalent disulphide bonds
  * Van der Waals forces

Answer 13

Tertiary structure

Question 14

• Multimeric proteins
• Chains held together by interactions between ionised, polar and nonpolar side chains and covalent disulphide covalent bonds

Answer 14

Quaternary structure