1. lipids and carbs fact test Flashcards
what is a monomer
the smaller units from which larger molecules are made
what is a polymer
molecules made from a large number of monomers joined together
what are some examples of monomers
monosaccharides, amino acids and nuceotides
what are some examples of polymers
polysaccharides, proteins, polypeptides and DNA
what is a condensation reaction
joins 2 molecules together with the formation of a chemical bond and involves the elimination of a water molecule
what is a hydrolysis reaction
breaks a chemical bond between 2 molecules and involves the use of a water molecule
what are monosaccharides
monomers from which larger carbohydrates are made
what are some common monosaccharides
glucose, fructose and galactose
what does a condensation reaction between 2 monosaccharides form
a glycosidic bond
what are disaccharides
formed by the condensation between 2 monosaccharides
what monosaccharides make the disaccharide maltose
2 glucose molecules
what monosaccharides make the disaccharide sucrose
glucose and fructose
what monosaccharides make the disaccharide lactose
glucose and galactose
what are the 2 isomers of glucose called
alpha glucose
beta glucose
what are polysaccharides
formed by the condensation of many glucose units
what are the 4 polysaccharides
cellulose
starch - amylose
starch - amylopectin
glycogen
what is cellulose like
- found in plants
- unbranched
- made of beta glucose
- bond between monomers is 1-4
- provides strength
- long, straight unbranched chains of beta glucose
joined by hydrogen bonding to form microfibrils which provides strength
what is starch (amylose) like
- found in plants
- unbranched
- made of alpha glucose
- bond between monomers is 1-4
- stores energy
what is starch (amylopectin) like
- found in plants
- branched
- made of alpha glucose
- bonds between monomers are -4 and 1-6
stores energy - branched therefore more ends for faster hydrolysis
what is glycogen like
- found in animals
- branched
- made of alpha glucose
- bonds between monomers is 1-4 and 1-6
- stores energy
- branched therefore more ends for faster hydrolysis
what do amylose, amylopectin and glycogen have in common
- polymer of alpha glucose so easily hydrolysed to provide glucose for respiration
- has coils therefore compact
- made of glucose so provides respiratory substrate for energy release
- insoluble so doesn’t affect water potential/osmosis
- large molecule so can’t cross the cell membrane
what is the test for starch
- grind/crush food sample
- add iodine in potassium iodide solution
- positive result is colour change from orange/brown to blue/black
what are reducing sugars
a reducing sugar is a sugar that can donate electrons (i.e. reduce) another chemical e.g benedict’s reagent
what are some examples of reducing sugars
all monosaccharides and some disaccharides e.g maltose