Carbohydrates -Starch - Glycogen- Cellulose

Question 1

Is glucose soluble or insoluble + why

Answer 1

Very soluble
Because has a large number of hydroxyl groups
Hydroxyl group are polar ( oxygen negative, hydrogen positive charge)
So they can form hydrogen bonds easily with water

Question 2

Problem if cell contain too much dissolved glucose

Answer 2

Water moves into the cells by osmosis

Question 3

How to plants cells store excess glucose

Answer 3

As starch

Question 4

What 2 molecules does starch consist of

Answer 4

Amylose
Amylopectin

Question 5

What happens if we join together a large number of a-glucose molecules

Answer 5

Make polysaccharide amylose and amylopectin

Question 6

Describe structure of amylopectin

Answer 6

Highly branched
Polymer a glucose

Question 7

Difference between amylose and amylopectin

Answer 7

Amylopectin is a branched polysaccharide

Question 8

Structure of amylose related to it’s function x3

Answer 8

Tight helix- compact - store large amount of glucose molecules
Insoluble in water - prevents water entering cells by osmosis
Polymers to large to diffuse out of cell membrain

Question 9

Structure of amylopectin related to its breakdown

Answer 9

Enzymes work at ends to breakdown starch
Amylopectin large number of branches - large number of ends
Can break down more rapidly

Question 10

Glucose is stored as ….. in plants

Answer 10

Starch

Question 11

Glucose is stored as ….. in animals

Answer 11

Glycogen

Question 12

Where are the major stores of glycogen found

Answer 12

Liver and muscle cells

Question 13

Monomer of glycogen

Answer 13

Polymer of a- glucose

Question 14

What does glycogen have a similar structure to + difference

Answer 14

Amylopectin
Glycogen has more branches

Question 15

Advantage of glycogen having lots of branches ( 4 steps)

Answer 15

Enzymes work at the end of molecules
The more branches the more free ends
Enzymes can convert glycogen more quickly to glucose
High rate respiration

Question 16

Glycogen soluble or insoluble

Answer 16

Insoluble- means does not draw water into cells by osmosis

Question 17

Glycogen large or small molecule

Answer 17

Large can’t diffuse out of cell

Question 18

Where is cellulose used

Answer 18

In the cell wall

Question 19

Structure of cellulose ( which glucose)

Answer 19

Polymer of b-glucose

Question 20

What happens when 2 b-glucose molecules join together ( structure)

Answer 20

The hydroxyl groups are on diagonals
Every 2nd b-glucose molecule flips
Forms glycosidic bonds between 1,4

Question 21

Is cellulose branched or unbranched polysaccharide

Answer 21

Unbranched

Question 22

What bonds form between chains of cellulose

Answer 22

Hydrogen bonds

Question 23

Why is cellulose strong

Answer 23

Large number of hydrogen bonds between chains of cellulose

Question 24

What are the fibres between cellulose called

Answer 24

Microfibril

Question 25

What happens when lots of microfibrils join together and next ( applies to cellulose only )

Answer 25

Large structure called macrofibrils
Macrofibrils join to form Fiber

Question 26

Describe how the structure of glycogen relates to its function x4

Answer 26

Coil so compact
Branches some more and for fast hydrolysis
Insoluble so does not affect osmosis
Polymer of glucose so easily hydrolysed

Question 27

How is cellulose adapted for its function

Answer 27

Long,straight chains joined by hydrogen bonds
Microfibril between layers
Increase strength

Question 28

Give two ways that the structure of starch is similar to cellulose

Answer 28

Both have glycosidic bonds
Are polymers of monosaccharides

Question 29

Structure of glycogen related to function x5

Answer 29

Helix so compact
Polymer of glucose so easily hydrolysed
Branched so more ends for faster hydrolysis
Glucose so provides respiratory substrate for energy releases
Insolvable so does not effect osmosis