2.1.2 carbohydrates

Question 1

what is a monosaccharide?

Answer 1

a single unit of a sugar
i.e glucose, fructose, galactose

Question 2

what is a disaccharide?

Answer 2

when two monosacc. bond together
i.e maltose, sucrose, lactose

Question 3

what is a polysaccharide?

Answer 3

when two or more monosacc. bond together
i.e starch, glycogen, cellulose

Question 4

what is glucose?

Answer 4

hexose monosaccharide
C6H12O6
it is an energy store in plants
respiratory substrate
always labelled in a clockwise direction

Question 5

describe the difference between alpha and beta glucose

Answer 5

alpha glucose has the OH group at the bottom and H on top
beta glucose has the OH group on the top and H on the bottom
remember ABBA

Question 6

explain why glucose is solvable in water?

Answer 6

due to the hydrogen bond between OH groups and the water molecules
allows it to be dissolved in cytosol of cell

Question 7

describe the formation of maltose/disaccharides

Answer 7

the OH groups of C1 and C4 will bond during a CONDENSATION reaction
1,4 glycosidic bond
produces water and forms disaccharide
2 alpha glucose = maltose

Question 8

how is sucrose formed?

Answer 8

when glucose and fructose bond
found in fruits

Question 9

how is lactose formed?

Answer 9

when glucose and galactose formed
found in milk

Question 10

what are the other types of monosaccharides?

Answer 10

pentoses = 5 carbons
includes ribose (RNA nucleotides) and deoxyribose (DNA nucleotides)
triodes = 3 carbons