monomer, polymer, carbohydrates, lipids

what is a monomer

a small basic molecular unit eg amino acid

what is a polymer

a large complex molecule composed of long chains of monomers eg proteins

what elements are carbohydrates made up of

carbon, hydrogen, oxygen and nitrogen

name the 3 monosaccharides

• glucose

• fructose

• galactose

name the 3 disaccharides

• sucrose

• maltose

• galactose

name the 3 polysaccharides

• starch

• cellulose

• glycogen

alpha glucose

beta glucose

what is an isomer

same molecular formula but different structure

what is a disaccharide

which bonds form

which reaction forms it

a pair of monosaccharides joined by glycosidic bond formed by a condensation reaction

glucose + glucose —> ________ + water

maltose

glucose + _______ —> lactose + water

galactose

glucose + _______ —> sucrose + water

fructose

what is a condensation reaction

the joining of two molecules joined together by removing water

what is hydrolysis

the splitting of molecules through the addition of water

where do bonds form in a disaccharide

1-4 glycosidic bond (2 H and 1 0)

what is a polysaccharide

what reaction forms it

many glucose monomers joined via a condensation reaction

starch

• monomer and bond between them

alpha glucose

1-4 glycosidic bonds (amylose)

1-4 , 1-6 glycosidic bonds (amylopectin)

starch

• function and location

• insoluble store of glucose

• starch grains inside of plant cells

explain starch structure and how it related to its function

• made of 2 polymers. amylose which is an unbranched helix and amylopectin with is a branched molecule

• the helix can compact to fit into smaller spaces. the branches increase the surface area for rapid hydrolysis into glucose. it is insoluble so won’t effect water potential

cellulose

• monomer and bonds between them

beta glucose

1-4 glycosidic bonds + hydrogen bonds

cellulose

• function and location

• provide structural strength to cell wall

• cell wall of plants

describe the structure of cellulose and how it relates to its function

• made up of long straight chains held together by many hydrogen bonds - fibrils

• the many hydrogen bonds provides collective strength. insoluble so won’t effect water potential or osmosis

glycogen

• monomer and bonds between them

alpha glucose

1-4 glycosidic bonds and many more 1-6 glycosidic bonds

glycogen

• function and location

• insoluble store of glucose

• muscle and liver cells of animals

describe the structure of glycogen and how it relates to its function

highly branched molecule which increases surface area for rapid hydrolysis back to glucose and more points for the enzymes to attach. insoluble so won’t effect water potential.

triglyceride

• reaction

• what’s it’s made up of

• what bonds are formed

formed via a condensation reaction between one glycerol and three fatty acids (3 waters) to form 3 ester bonds (in the carboxylic group)

phospholipid

• what reaction

• what’s it made up of

• what bond is formed

formed via a condensation reaction between one glycerol molecule, two fatty acid chains and a phosphate group attached to a glycerol. two ester bonds form.

properties of triglycerides (4)

• energy storage

large ration of C-H bonds compared to number of C atoms so a lot of energy can be stored in the molecule

• metabolic water source

high ratio of H + O atoms so will release water when oxidised

• insoluble

larger and hydrophobic so won’t effect water potential and osmosis

• relatively low mass

a lot can be stored without increasing mass and preventing movement

properties of phospholipid (4)

• hydrophilic head that attracts water when charged

• the charge will repel other fats

• has a hydrophobic tail so repels water and mixes with fats

• polar head exposed to water and tails are not to form a phospholipid bilayer membrane which makes up the plasma membrane around cells

how do you test for lipids

dissolve sample is ethanol and shake

add distilled water and shake

if a white emulsion appears then it is positive