Use LEFT and RIGHT arrow keys to navigate between flashcards;
Use UP and DOWN arrow keys to flip the card;
H to show hint;
A reads text to speech;
21 Cards in this Set
- Front
- Back
|
what is used to test for starch? |
iodine solution |
|
|
what is used to test for sugars? |
benedict’s |
|
|
what is used to test for protein? |
biuret |
|
|
what is used to test for fats |
ethanol |
|
|
what colour does a positive starch test tirn |
iodine goes from yellow/brown to blue/black |
|
|
what colour does a positive test for reducing sugars turn? |
benedict’s turns from blue to red brick precipitate |
|
|
what colour does a positive test for protein turn? |
biuret turns blue to lilac/purple |
|
|
what colour does a positive test for fats turn? |
ethanol turns colourless to form a white emulsion |
|
|
what do carbohydrates provide? |
energy |
|
|
how do you use biuret to test for protein? |
add sodium hydroxide to the food solution then add copper sulphate and shake |
|
|
how do you use ethanol to test for fats? |
mix the fat with ethanol to dissolve some of it then add it to water |
|
|
what is fat used for? |
insulation protects organs energy store |
|
|
name a simple sugar |
-glucose -lactose |
|
|
name a complex polysaccharide |
- starch - cellulose - glycogen |
|
|
what are proteins used for? |
growth and repair of cells can be used for energy |
|
|
what do you find proteins in? |
- lean meat - fish - egg white |
|
|
explain fats structure |
one glycerol and three fatty acid chains |
|
|
foods high in fat? |
cheese lard streaky bacon |
|
|
where is cellulose found? |
plant cell walls |
|
|
how do you use iodine to test for starch? |
add iodine to the food |
|
|
how do you use benedict’s to test for reducing sugars? |
add solution to the food and heat on a hot water bath |
