Biological molecules Flashcards
what are organic molecules?
carbon- based molecules that make up living organisms
what are carbohydrates? (3)
C,H,O - bread,potato,pasta
- made up of simple sugars
- provide us with energy
-glucose- simple carb made up of a simple carb molecule
what can glucose molecules be combined in LONG CHAINS to form?
complex carbs like
-cellulose in plants ( CELL WALL)
-starch, glycogen
what are lipids? (3)
C,H,O
-Fats ( solid at RT) and oils ( liquid at RT)
-long term energy store in our cells
-+used for insulation
what can they be used to make when combined with other molecules?
cell membranes (phospholipids)
are they soluble or insoluble in water
insoluble
what are they made up of ?
3 molecules of fatty acids + 1 glycerol
foods that are lipids?
oil, cheese, butter, salmon
Proteins- what are they made up of?
amino acids joined together in long chains ( 20 diff type)
what elements do they have?
C, H, O, N and sometimes S
what foods have proteins?
meat, cheese, fish, pulses, tofu
what are the uses of carbs
-energy source
- used in respiration
- used to form cellulose cell wall in plants
what are some problems due to deficiency of carbs
-lack of energy due to lack of glucose for respiration
- poor growth in plants as cell walls cannot be made
what are the uses of lipids?
-energy store
-insulation
- used for cell membranes
problems due to deficiency from lipids
-poor heat insulation and lack of energy
- new cells cannot be formed as CELL MEMBRANES NEED LIPIDS
what are the uses of proteins?
used to build cells and make enzymes
what happens if you lack proteins?
-lack of growth+ lack of repair of cells
-lose muscle mass
-hard to keep balance
-slowed metabolism
-kwashiorkor
how do you make a food sample?
- break it using a pestle+mortar
-put it in a beaker, add distilled water
-mix with glass rod - filter using funnel+ filter paper
what is the food test for carbs/glucose
Benedicts solution 3-4 drops
-place test tube in water bath( 80°) for 5 min
results for benedicts solution
Green-orange = low conc. of glucose
Brick red = high conc.
Blue= no change
test for starch
add iodine solution + gently shake
results for iodine solution
blue-black= starch is present
stays brown-orange= starch not present
test for proteins
add biuret solution ( corrosive )
gently shake
result for biuret solution
turns lilac- yes proteins
stays blue- no protein
test for lipids
add distilled water+ ethanol ( flammable)
gently shake
result for ethanol test
milky-white emulsion= yes lipids
what is a catalyst?
a substance which increase the speed of a chemical reaction without being used up/ changed in reaction
