Human Nutrition Flashcards
what are biological molecules?
long, complex molecules made up from smaller basic units.
give 3 examples of biological molecules?
- carbohydrates
- lipids (fats and oils)
- proteins
what elements do carbohydrate molecules contain?
3 examples
carbon
hydrogen
oxygen
how are starch and glycogen related to carbohydrates?
they are large, complex carbohydrates
-> that are made up of many smaller units joined together in a long chain
what are proteins made up of?
long chains of amino acids.
what do proteins contain?
4 things
- carbon
- nitrogen
- oxygen
- hydrogen
what are lipids made up of?
FATTY ACIDS and GLYCEROL
what do lipids contain?
3 things
- carbon
- hydrogen
- oxygen
what do you need to do before a food test?
you need to make a sample
How do you identify if a food sample contains glucose?
give the step by step test: 5 steps
By using Benedict’s test:
1) prepare a food sample. Transfer 5cm(3) to test tube
2) prepare water bath. Set it to 75 degrees C
3) add Benedict’s solution to test tube (10 drops) using a pipette
4) place test tube in water bath using a test tube holder. Leave for 5 minutes. Make sure the tube is pointing away from you
5) if food sample contains glucose, solution will become: green or yellow -> low concentrations of glucose
brick red -> high concentrations of glucose
YOU CAN DO THIS :)
I BELIEVE IN YOU!!!
<3
How do you identify if the type of biological molecules a sample contains starch?
(give the step by step test: 2 steps)
1) make a food sample. Transfer 5 cm (3) of your sample to test tube
2) add a few drops of iodine solution, gently shake the tube to mix the contents. If sample contains starch, the colour of the solution will change from browny-orange to black or blue-black
give 3 examples of starch
- pasta
- rice
- potatoes
How do you identify if the type of biological molecules a sample contains proteins?
(give the step by step test: 3 steps)
Use Biuret test
1) prepare a food sample. Transfer 2 cm(3) of your sample to a test tube
2) add 2 cm(3) of biuret solution to the sample. Mix the contents of the tube by gently shaking it
3) if the food sample contains protein, the solution will change from blue to pink or purple. If no protein is present, the solution will stay blue
give 2 examples of proteins
- meat
- cheese
give 3 examples of lipids
- olive oil
- margarine
- milk
what do you need to do to get different nutrients into your body?
you need to eat different foods
where can you find carbohydrates?
3 examples
- pasta
- rice
- sugar
what is the function of carbohydrates?
to give you energy
what is the function of lipids?
provide energy, act like an energy store, provide insulation
where can you find vitamin A?
1 example
liver
what is the function of vitamin A?
improve vision and keep your skin and hair healthy
where can you find vitamin C?
1 example
oranges
what is the function of vitamin C?
prevent scurvy
where can you find vitamin D?
2 examples
- eggs
- can also be absorbed by your body when skin is exposed into sunlight
what is the function of vitamin D?
calcium absorption
where can you find calcium (mineral ion)?
2 examples
- milk
- cheese
what is the function of calcium (mineral ion)?
make bones and teeth
where can you find iron (mineral ion)?
1 example
red meat
what is the function of iron (mineral ion)?
to make haemoglobin for healthy blood
where can you find water?
2 examples
food and drinks
what is the function of water?
every bodily function relies on water, we need constant supply to replace water lost through urinating, breathing and sweating
where can you find dietary fibre?
2 examples
- wholemeal bread
- fruit
what is the function of dietary fibre?
aids the movement of food through the gut