BIOLOGICAL MOLECULES (NUTRIENTS)

glucose + glucose

maltose

glucose + galactose

lactose

fructose + glucose

sucrose

hydrolysis/hydrolytic reaction

water molecule is needed to break up a complex molecule into smaller molecules

starch role

storage found in carbohydrates, can be digested to glucose to provide energy for cell activities

where is starch found

storage organs of plants

cellulose role

cellulous cell wall protects plant cells from bursting or damage

cannot be digested in intestines, serve as dietary fibre that prevents constipation

where is cellulose found

cellulose cell wall

glycogen role

storage form of carbohydrates in mammals

when needed, it is digested into glucose to provide energy for cell activities

where is glycogen found

liver and muscle of mammals

why are starch and glucose suitable as storage materials in mammals

insoluble, do not change water potential in cells

large molecules which cannot diffuse through cell membrane, cannot be lost from cell

easily hydrolysed to glucose when needed

compact shapes, occupy less space than all the individual glucose molecules that make up starch or glycogen molecules

breakdown of starch

amylase digests starch to form maltose

maltose is hydrolysed to glucose by maltase

functions of carbs

substrate for respiration, to provide energy for cell activities

form supporting structures like cell wall

converted into other organic compounds like amino acids and fats

formation of nucleic acid like DNA
synthesise lubricants and nectar in some flowers