carbohydrates

Question 1

function of amylose

Answer 1

-stores glucose I plants for respiration

Question 2

what are the molecules in amylose?

Answer 2

-polymer of alpha glucose molecules, joined by 1-4 glycosidic bonds

Question 3

structure of amylose

Answer 3

-unbranched
-compact so it stores lots of glucose in a small space
-large so the polymer can’t cross the cell membrane by diffusion
-soluble in water
-twists into complex helix with hydrogen bonds

Question 4

function of amylopectin

Answer 4

stores glucose in plants for respiration

Question 5

what are the molecules in amylopectin?

Answer 5

-alpha glucose molecules joined by 1-4 and 1-6 glycosidic bonds

Question 6

structure of amylopectin

Answer 6

-branched so hydrolysis occurs more rapidly
-compact (due to helix) to store lots of glucose in a small space
-large so the polymer can’t cross the membrane
-insoluble in water so doesn’t affect osmosis

Question 7

how do you draw an alpha caucuses molecule?

Answer 7

-draw hexagon with oxygen at top right point and carbons at others
-carbon 6 extends from carbon 5
-C1-C4 have H and OH, H must be above Oh on C1
-C5 has only H
-C6 has OH and H²

Question 8

how do you draw a beta glucose molecule?

Answer 8

-draw hexagon with oxygen at top right point and carbons at others
-carbon 6 extends from carbon 5
-C1-C4 have H and OH, OH must be above H on C1
-C5 has only H
-C6 has OH and H²

Question 9

3 examples of hexose sugars (6 carbons)

Answer 9

glucose, galactose, fructose

Question 10

what is a pentose sugar?

Answer 10

has 5 carbons, eg ribose

Question 11

how do disaccharides form between glucose

Answer 11

-condensation reaction
-glycosidic bond
-molecule of water produced (H²O removed)

Question 12

how do you form sucrose, lactose and maltose?

Answer 12

sucrose- glucose and fructose
lactose-glucose and galactose
maltose-alpha glucose and glucose

Question 13

3 properties of glucose

Answer 13

-water soluble-contains large amount of hydroxyl groups
-polar-small negative charge on oxygen, small positive charge on hydrogen
-induces osmosis-if cell contains lots of soluble glucose

Question 14

what are the 3 types of polysaccharide?

Answer 14

starch-amylose and amylopectin
cellulose
glycogen

Question 15

what is the function of cellulose?

Answer 15

a major part of cell surface membranes in plants

Question 16

what are the molecules of cellulose?

Answer 16

-1-4 glycosidic bond where every second beta glucose flips
-weak intermolecular forces between layers held by hydrogen bonds

Question 17

what is the structure of cellulose?

Answer 17

-unbranched to create straight chain with layers
-mechanically very strong due to huge number of bonds (inflexible)
-cellulose cell wall must resist force of cell content pushing against it
-high tensile strength
-insoluble in water

Question 18

cellulose-what are micro and macrofibrils

Answer 18

-microfibril made when cellulose chains group together
-macrofibril made when microfibrils group together
-cellulose fibre formed when macrofibrils group together
plant cell wall formed by cellulose fibres

Question 19

function of glycogen

Answer 19

-storage form of glucose
-found in liver muscle tissue

Question 20

structure of glycogen

Answer 20

-very branched chains so lots of ends for hydrolysis-rapid break down is necessary for respiring and energetic animals
-insoluble so does not induce osmosis
-large molecule so cannot diffuse out of the cell
-short branches allow more energy storage

Question 21

molecules of glycogen

Answer 21

-connected mostly by 1-4 bonds
-some branches joined by 1-6 glycosidic bonds

Question 22

is sucrose non reducing

Answer 22

yes