Carbohydrates

Question 1

How are carbohydrates classified into their 3 groups

Answer 1

Monosaccharides, Disaccharides, polysaccharide

Question 2

What are monosaccharides and Give examples of monosaccharides

Answer 2

monosaccharides are the monomers from which larger carbohydrates are made

Glucose, galactose and fructose

Question 3

How are disaccharides formed and give examples of Disaccharides

Answer 3

Formed by the condensation of two monosaccharides.
Glucose+glucose=maltose
Glucose + fructose= sucrose
Glucose + galactose= lactose

Question 4

What are polysaccharides and give examples of polysaccharides

Answer 4

formed by the condensation of glucose units. e.g. starch(amylopectin and amylose), glycogen and cellulose

Question 5

What is the difference between alpha glucose and beta glucose

Answer 5

Alpha glucose the OH groups is below C1 and C4

Beta glucose the OH group is above C1 and below C4

Question 6

How is the structure of glycogen related to its function

Answer 6

function = energy store in animal cells. Also found in bacteria and animals, not plants
Structure:
-polysaccharide of alpha glucose
-Highly branched so can be rapidly hydrolysed to release glucose for respiration to provide energy.
-Large molecule so cant leave cell
-insoluble to water, so water potential no affected so no osmotic effect.

Question 7

How is the structure of starch related to its function?

Answer 7

Function :energy store in plants
Structure
-polysaccharide of alpha glucose
-made of amylose and amylopectin
-glycosidic bonds in amylose and unbranched
-glycosidic bonds in amylopectin branched
- this allows it to be helical so it makes it compact for storage in cells
-Large polysaccharide molecule can’t leave cells
-Insoluble in water so water potential of cell not affected so no osmotic pressure

Question 8

How is the structure of cellulose related to its function?

Answer 8

Function: component of plant cell walls and provides rigidity to the plant cell.

structure

• made of beta glucose and so form long straight unbranched chains
• these chains run parallel to each other and are cross linked by H bonds which adds collective strength.
• this then forms a microfibrils which form fibres which provides in more strength.