cellulose- lqc 1b

Question 1

function of cellulose

Answer 1

structural component of plant cell walls- to provide strength and support

Question 2

an a-alpha glucose has

Answer 2

two hydroxyl groups adjacent to one another

Question 3

is cellulose made of alpha or beta glucose

Answer 3

B-glucose

Question 4

what type of bond joins two B-glucose molecules in cellulose

Answer 4

B 1-4 glycosidic bond

Question 5

what type of reaction joins the two B-glucose molecules in cellulose

Answer 5

condensation

Question 6

every alternate B-glucose in cellulose is

Answer 6

inverted

Question 7

is cellulose branched or unbranched

Answer 7

unbranched (it only contains B 1-4 glycosidic bonds)

Question 8

describe the structure of cellulose microfibril

Answer 8

· Contains beta glucose
· Joined by β 1-4 glycosidic bonds in condensation reactions
· Unbranched chain
· Alternate glucose molecules in the chain are inverted
· Microfibril composed of many (60-70) cellulose molecules held together by hydrogen bonds

Question 9

cellulose molecules join together to form

Answer 9

cellulose microfibril

Question 10

structure of a plant cell wall

Answer 10

· made of cellulose molecules - made of beta/ β glucose joined by β 1-4 glycosidic bonds, with every alternate glucose inverted , forming an unbranched chain
· bundles of many cellulose molecules are held together by hydrogen bonds between adjacent molecules to form a cellulose microfibril
· layers of microfibrils are laid down at different angles to each other form a mesh , which is then embedded in a matrix of hemicelluloses and pectins to form the primary cell wall
· secondary thickening is when lignin is added to form the secondary cell wall