Nutrition in Humans Flashcards
Carbohydrates
- Sources: ?
- Functions: ?
- Sources: pasta, rice
- Functions: provide energy
Lipids (fats and oils)
- Sources: ?
- Functions: ?
- Sources: butter, oily fish
- Functions: provide energy, act as an energy store and provide insulation
Proteins
- Sources: ?
- Functions: ?
- Sources: meat, fish
- Functions: needed for growth and repair of tissue, provide energy in emergencies
Vitamin A
- Sources: ?
- Functions: ?
- Deficiency: ?
- Sources: liver
- Functions: helps to improve vision and keep your skin and hair healthy
- Deficiency: night blindness
Vitamin C
- Sources: ?
- Functions: ?
- Deficiency: ?
- Sources: oranges
- Functions: helps wounds to heal
- Deficiency: scurvy
Vitamin D
- Sources: ?
- Functions: ?
- Deficiency: ?
- Sources: eggs
- Functions: needed for calcium absorption
- Deficiency: rickets
Calcium
- Sources: ?
- Functions: ?
- Sources: milk, cheese
- Functions: needed to make bones and teeth
Iron
- Sources: ?
- Functions: ?
- Deficiency: ?
- Sources: red meat
- Functions: needed to make haemoglobin for healthy blood
- Deficiency: anaemia
Water
- Sources: ?
- Functions: ?
- Sources: food and drink
- Functions: needed for most bodily functions, replace water lost through breathing, sweating and urinating
Dietary fibre
- Sources: ?
- Functions: ?
- Sources: whole meal bread
- Functions: aids the movement of food through the gut
How do energy level requirements vary with activity levels?
Active people need more energy, as they burn more fat
How do energy level requirements vary with age?
Children and teenagers need more energy than older people - they need energy to grow and they’re generally more active
How do energy level requirements vary with pregnancy?
Pregnant woman need more energy than other women - they’ve got to provide the energy to their babies need to develop
What is the structure of a protein?
Many amino acids (containing carbon, nitrogen, hydrogen and oxygen) linked together
What is the structure of a lipid?
One glycerol molecule linked to three fatty acid molecules
What is the structure of a carbohydrate?
Starch and glycogen are made from many simple sugars (glucose) linked together
Describe the test for starch
Put food on dropping tile
Add a few drops of IODINE to food
Starch present: blue/black colour
Starch absent: brown colour
Describe the test for glucose/sugar
Put food in a test tube
Add a few drops of BENEDICT’S REAGENT to food
Heat in a beaker of hot water
Sugar present: orange precipitate
Sugar absent: blue colour
Describe the test for proteins
Put food in a test tube
Add a few drops of dilute SODIUM HYDROXIDE to food, followed by the same amount of dilute COPPER SULPHATE
Protein present: lilac colour
Protein absent: blue colour
Describe an experiment to identify the energy content in a food sample
Fill a test tube with 20cm cubed of water and clamp it to a clamp stand.
Weigh the food sample with a balance to find its mass and put it on a mounted needle. Measure the temperature of the water in the test tube with a thermometer and record it.
Burn the food sample with a Bunsen burner and put it under the test tube until it’s completely burnt out.
Record the temperature of the water again and calculate the temperature difference.
Use this equation to calculate the energy content:
Energy released from food per gram (J) = mass of water (g) x temperature rise (degrees Celsius) x 4.2 divided by mass of food sample (g)
Describe the structure of the alimentary canal
Mouth, oesophagus, small intestine, large intestine, anus
Describe the function of the mouth
- teeth break down food mechanically
- salivary glands in the mouth produce amylase enzyme
Describe the structure of the oesophagus
The muscular tube that connects the mouth and stomach
Describe the function of the stomach
- pummels food with its muscular walls
- produces the protease enzyme, pepsin
- produces hydrochloric acid which kills bacteria and provides the optimum pH for the protease enzyme to work (pH2 - acidic)
