Carbohydrates-polysaccharides

Question 1

What are three ways a polysaccharide can be formed

Answer 1

-By linking disaccharides and
monosaccharides via glycosidic bonds.
-By linking multiple
disaccharides via glycosidic bonds.
-By linking 2+ monosaccharides
via glycosidic bonds.

Question 2

What are the two energy storage polysaccharides of carbohydrates?

Answer 2

Starch and glycogen , both are made of alpha glucose and have 1-4 and 1-6 glycosidic bonding.

Question 3

What organism stores excess alpha glucose as starch?

Answer 3

plants

Question 4

What organism stores excess alpha glucose as glycogen?

Answer 4

animals

Question 5

What two polysaccharides make up starch?

Answer 5

amylopectin(80%) and amylose (20%)

Question 6

What is the structural material polysaccharide of carbohydrates?

Answer 6

cellulose, it is made of beta glucose

Question 7

What organism does cellulose act as a structural material in?

Answer 7

plants

Question 8

What are the properties of alpha glucose

Answer 8

soluble ,sweet , small , easily transported and detected.

Question 9

Why do plants and animals need to store excess alpha glucose?

Answer 9

If they fail to store excess glucose effectively this could impact the cells environment , it could go from hypotonic to isotonic or hypertonic(draw three diagrams).

Question 10

How does excess alpha glucose affect osmosis?

Answer 10

excess alpha glucose is soluble so if it is not stored then it can dissolve and impact osmosis , however when it is stored as either starch or glycogen it is insoluble so it doesn’t effect osmosis.

Question 11

(Starch is 80% amylopectin)What is the structure of amylopectin?

Answer 11

-long branched chain of alpha glucose, due to abundance of branches more glucose molecules can be snipped of by hydrolysis at once when lots of energy is required.It coils into a spiral with branches emerging from it , held together by H bonds.Draw a diagram

Question 12

What type of bonding is in amylopectin

Answer 12

1-4 and 1-6 glycosidic

Question 13

what are the properties of amylopectin?

Answer 13

large, hard to transport, insoluble, multiple break off points for hydrolysis , multiple attachment points for condensation reactions

Question 14

(Starch is made of 20% amylose) What is the structure of amylose?

Answer 14

As it forms it coils into a spiral which is compact due to the bond angles it forms at, it is stabilised with H bonds .Draw a diagram of it.

Question 15

What is the bonding of amylose?

Answer 15

large, insoluble , few break off and attachment points since its coiled , compact , difficult to transport .

Question 16

What is glycogen stored as?

Answer 16

dense small granules in liver and muscle cells

Question 17

What is the structure of glycogen?

Answer 17

It coils into a spiral with branches coming out of it, It has hydrogen bonds , It is more branched then amylopectin and it is abundant in side branches.Draw the structure.

Question 18

What type of bonding is in glycogen

Answer 18

1-4 and 1-6 glycosidic bonding

Question 19

Why is glycogen abundant in side branches

Answer 19

It needs to be abundant in side branches so glucose is easily snipped off from the ends of chains when needed in respiration.

Question 20

what are the properties of glycogen?

Answer 20

Insoluble,large,more attachment and break off points, abundant in side branches and its compact.

Question 21

What is the structure of cellulose?

Answer 21

Straight beta glucose chains which lie side by side rather than spiralling like alpha glucose chains.Draw the structure

Question 22

Why do cellulose chains not spiral and remain straight?

Answer 22

The H atoms and -OH groups are inverted in beta glucose compared to alpha glucose which means every other b glucose molecule is rotated 180.This and hydrogen and 1-4 glycosidic bonding stops the chain from spiralling.

Question 23

Why can hydrogen bonds form between different chains of cellulose?

Answer 23

the -OH group on carbon 2 sticks out which allows this.

Question 24

How many cellulose chains does it take to form microfibrils?

Answer 24

60-70

Question 25

How wide is the diameter of microfibrils?

Answer 25

10-30nm

Question 26

How many microfibril bundles does it take to form macrofibrils?

Answer 26

up to 400

Question 27

What are macrofibrils and microfibrils embedded in?

Answer 27

its embedded in pectin and hemicellulose(both are polysaccharides) to form the cell wall

Question 28

What gives micro and macrofibrils high tensile strength?

Answer 28

Due to hydrogen bonds between chains and glycosidic bonding and high tensile strength prevents cells from bursting when turgid and protects the cell membrane.

Question 29

what type of bonding is in cellulose

Answer 29

1-4 glycosidic bonding and hydrogen bonds which form between hydroxyl groups of adjacent chains.

Question 30

What gives micro and macrofibrils more strength?

Answer 30

They criss cross the cell wall despite being embedded in hemicellulose and pectin.

Question 31

How can micro and macrofibrils criss cross the cell wall if they are embedded

Answer 31

They are embedded in a gel like matrix (pectin and hemicellulose) that surrounds and supports them.

Question 32

Can cellulose be digested

Answer 32

its very difficult to digest since its glycosidic bonds are hard to break , plants don't have the enzyme to catalyse this anyways.

Question 33

What makes the cell wall permeable

Answer 33

There is space between macrofibrils and microfibrils for water and mineral ions to pass in and out.

Question 34

how can the macrofibril structure be reinforced

Answer 34

by other substances for extra support