Carbohydrates (3.1.2)

Question 1

What are monosaccharides?

Answer 1

• The monomers from which larger carbohydrates are made

Question 2

Give examples of monosaccharides

Answer 2

• Glucose
• Galactose
• Fructose

Question 3

What are the isomers for glucose?

Answer 3

• α glucose
• β glucose

Question 4

What are disaccharides?

Answer 4

• When two monosaccharides are joined together by a glycosidic bond formed in a condensation reaction

Question 5

What is maltose made up of?

Answer 5

• Two glucose molecules

Question 6

What is sucrose made up of?

Answer 6

• Glucose and fructose

Question 7

What is lactose made up of?

Answer 7

• Glucose and galactose

Question 8

How is the structure of starch ideally suited to its function as a storage compound?

Answer 8

• Large molecule → so can’t cross the cell membrane
• Insoluble in water → so osmotically inactive, so does not affect water potential
• Helical → so is compact
• Branched structure → allows easy release of glucose molecules for respiration

Question 9

How is the structure of glycogen ideally suited to its function as a storage compound?

Answer 9

• Large molecule → so cannot leave the cell
• Insoluble in water → so osmotically inactive, so does not affect water potential
• Many free ends → so can be compacted easily storing a large amount of glucose in a small space
• Branched structure → allows easy release of glucose molecules for respiration

Question 10

How is the structure of cellulose ideally suited to its function as a structural compound?

Answer 10

• Insoluble in water → so osmotically inactive, so does not affect water potential
• Long and straight chains of β-glucose molecules → these chains become linked together by many hydrogen bonds to form fibrils → this provides strength to the cell wall