Human nutrition Flashcards
What is a balanced diet?
A balanced diet has the correct amount of each group of nutrients (carbohydrates, fats, proteins, vitamins, minerals, dietary fibre and water). We need a balanced diet to stay healthy.
What are the 7 main food groups?
Carbohydrates
Protein
Fats
Dietary fibre
Vitamins (C and D)
Minerals (Iron and calcium)
Water
Function and sources of carbohydrates
Function: Source of energy, nutrient for producing energy
Sources: Bread, cereals, pasta, rice, potatoes
Function and sources of protein
Function: Growth (getting bigger by growing new cells), repair (replacing damaged or worn out cells)
Sources: Meat, fish, eggs, beans, nuts
Function and sources of lipids
Function: Insulation and energy storage, making cell membranes of cells
Sources: Butter, oil, cheese, margarine
Function and sources of dietary fibre
Function: Ensures food moves through intestines at the correct rate
Sources: Vegetables, whole grains
Function and sources of vitamins
Function: Needed in small quantities to maintain health
Sources: Fruit and vegetables
Function and sources of vitamin C
Function: Used in creating connective tissue, blood vessels, bones and cartilage. It’s required for wound healing.
Sources: Citrus fruits (lemon, lime, orange), strawberries, kiwifruit
What is the deficiency of vitamin C?
Scurvy (wounds over the skin that isn’t healed)
Function and sources of vitamin D
Function: Helps the body to absorb calcium. Needed to maintain strong, healthy bones and teeth
Sources: Main source is sunlight but can also be gained from fatty fish, egg yolks and dairy products
What is the deficiency of vitamin D?
Rickets (bowed legs)
Function and sources of minerals
Function: Needed in small quantities to maintain health
Sources: Fruits and vegetables, meats, dairy products
Function and sources of calcium
Function: Needed for strong bones and teeth and maintaining blood clotting
Sources: Milk, cheese, eggs, fish with bones
Function and sources of iron
Function: Required for making haemoglobin in red blood cells which is used to bind oxygen
Sources: Red meat, whole grains, leafy green vegetables
Function and sources of water
Function: Acts as a solvent for cellular reactions, circulatory system and digestion system, helps to maintain body temperature
Sources: Water, juice, milk, fruits and vegetables
What are the main organs in the digestive system
mouth, salivary glands, oesophagus,
stomach, small intestine (duodenum and ileum), large intestine (colon, rectum,
anus), pancreas,
liver and gall bladder
What is the function of the mouth?
The mouth is where mechanical digestion takes place. The teeth grind the food into small pieces to increase its surface area to volume ratio. The salivary glands release saliva in the mouth. The saliva contains amylase enzymes which break down starch into maltose. Another enzyme maltase breaks down maltose to glucose. At the back of the mouth, the food is made into a ball called bolus by the tongue and lubricated in saliva so it can be swallowed easily.
What is the function of the oesophagus?
The tube that connects the mouth to the stomach. The bolus goes here after being swallowed and is pushed down the oesophagus by wave-like muscle contractions called peristalsis.
What is the function of the stomach?
The main organ where food is digested as it does both mechanical and chemical digestion. Food is mechanically digested by muscles that churn the food. Protease enzymes start to chemically digest proteins and hydrochloric acid is added to kill bacteria in food and provide the optimum pH for the enzymes to work.
What is the function of the small intestine?
Where nutrients are absorbed. The first section is the duodenum where food goes when it goes out of the stomach. This is where bile and digestive enzymes are added to further digest the food. At this point the pH of the small intestine is slightly alkaline at 8-9 because bile is basic. The second section is called the ileum and it’s where the absorption of digested food molecules takes place. The ileum is long and lined with villi to increase the surface area over which absorption takes place.