1.2 carbohydrates - monosaccharides

Question 1

what is the monomer of polysaccharides?

Answer 1

monosaccharides

Question 1

what are some features of monosaccharides?

Answer 1

• soluble in water
• sweet-tasting

Question 2

give the 3 types of monosaccharides.

Answer 2

• glucose
• fructose
• galactose

Question 3

what isomers are there for glucose? explain their difference.

Answer 3

• alpha & beta
• -OH groups on the same side in alpha & different in beta

Question 4

what is the test for reducing sugars?

Answer 4

• benedict’s test

Question 5

how does benedict’s reagent recognise sugars?

Answer 5

• benedict’s reagent is reduced by sugars, both monosaccharides & disaccharides
• alkaline copper (2) sulphate reduced with heat to copper (1) oxide, which gives red precipitate

Question 6

state the colour order of intensity in the semi-quantitative test of benedict’s reagent.

Answer 6

blue < green < yellow < brown < red