disaccharides

Question 1

how is a disaccharide formed?

Answer 1

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

Question 2

what is a condensation reaction?

Answer 2

a reaction in which smaller molecules join together and a new chemical bond is formed to form a larger molecule with the release of water

Question 3

what are three examples of disaccharides to remember?

Answer 3

maltose, sucrose and lactose

Question 4

what are the word equations for the formation of these three disaccharides?

Answer 4

glucose + glucose –> maltose + water
glucose + fructose –> sucrose + water
glucose + galactose –> lactose + water

Question 5

what is the general equation for the formation of disaccharides?

Answer 5

C6H12O6 + C6H12O6 –> C12H22O11 + H2O

Question 6

what idea is proved by this reaction?

Answer 6

conservation of mass

Question 7

how is a disaccharide broken down into it’s monosaccharides?

Answer 7

in a hydrolysis reaction

Question 8

what is a hydrolysis reaction?

Answer 8

the breakdown of a larger molecule into smaller molecules by the addition of water

Question 9

how can disaccharides be hydrolysed?

Answer 9

• boiling with acid eg dilute HCL
• heating with an enzyme at an optimum temperature