UNIT 1 (topic 1&2) carbohydrates Flashcards
define biological molecules
groups of chemicals that are found in living organisms
define monomer
one single unit that are linked to form long chains of polymers by condensation reactions
examples of monomers
monosaccharides, amino acids, nucleotides
define a polymer
multiple monomers bonded together which breaks down into monomers through hydrolysis reaction
define metabolism
the sum of all chemical reactions in the living organism
define ionic bonding
the transfer of electrons with electrostatic attraction with the opposite charges
define covalent bonding
the sharing of electrons with very strong and stable bonding
hydrogen bonding
electrostatic bond between two polar molecules (partially charged)
give an example of monosaccharides
glucose, fructose, galactose
give an example of polysaccharides
starch, glycogen, cellulose
what bond links monosaccharides together
glycosidic bond
what monomers are used for maltose
glucose and glucose
what monomers are used for sucrose
glucose and fructose
what monomers are used for lactose
glucose and galactose
what is the difference between alpha and beta glucose
Alpha- hydroxyl group is Above the first carbon
Beta- hydroxyl group Below the first carbon
define an isomer
same chemical formula but different layout - glucose
where is starch found
in plants as storage for excess glucose
what are the two types of starch and what’s the differences
amylose - alpha 1-4 glycosidic bonds
amylopectin - alpha 1-4 and 1-6 glycosidic bonds
properties of starch
- insoluble
- cannot leave the cell (usually in the chloroplasts)
- doesn’t effect water potential in the cell
- helical
- compact - lot of storage
where is glycogen found
in animals as storage for glucose (energy)
what are the benefits of the glycogen’s long branched chains
more access points for glucose to be released FOR RESPIRATION
are the properties of glycogen the same as starch
yes
where is cellulose found
in plants as structural support in the cell walls
what are the properties of cellulose
- polymer of beta-glucose that are inverted every other
- creates long straight unbranched chains
- chains layer on top of each other causing strong microfibrils between the hydrogen bonds
- strong structural support
which disaccharide is a NON-reducing sugar
sucrose
why are some sugars described as reducing sugar
any sugar that has/ can form an aldehyde group
explain the food test for proteins
- add biuret’s solution
- will go from light blue to lilac
explain the food test for a reducing sugar
- add benedict’s solution
- HEAT in a water bath
- will go from light blue to a range of green to red (depending on the concentration)
explain the food test for starch
- add iodine
- will go from orange to blue/ black
explain the food test for lipids
- add ethanol and shake
- AND THEN, add water
- will go from clear to a white milky emulsion
explain the food test for a non-reducing sugar
- carry out the benedict’s test first to check
- boil with HCL and neutralise (breaks into the two monomers)
- repeat the benedict’s test