7. (unfinished + too easy) Human nutrition Flashcards
What is a balanced diet?
A balanced diet provides adequate amounts of nutrients to ensure the body can maintain itself and function. It must have correct amounts of:
Proteins
Fats
Carbohydrates
Vitamins and minerals
Water
Fibre
State the principal dietary sources and describe the importance of Carbohydrates?
Carbohydrates are found in rice, pasta, potatoes, bread, yam, honey.
They include sugar and starches which break down to release energy for respiration
State the principal dietary sources and describe the importance of Proteins?
Found in meat, fish, milk, nuts.
Proteins are broken down to amino acids to allow cells to multiply. Excess amino acids cannot be stored in the body and can be used to provide energy.
Growth + Repair
State the principal dietary sources and describe the importance of Fats and oils?
Found in butter, oils, nuts, cheese.
Fats are used for long term energy storage and are found under the skin. They release twice as much as energy per gram compared to carbohydrates and are good insulators
State the principal dietary sources and describe the importance of Fibre ?
Found in vegetables, whole grains
Roughage comes from plants, it is mainly made up of cellulose from plant cells. Fibre adds bulk to food and cannot be digested. Muscles of the gut need something to push against and fibre helps this prevent constipation. Furthermore, it absorbs poisonous waste from our bacteria in our gut. MORE FIBRE DIET REDUCES CHANCES OF CHOLESTEROL IN BLOOD, HEART DISEASE, BOWEL CANCER.
What is the importance of water in our diet?
Water is needed for chemical reactions to take place and dissolves nutrients so that they can be transported around the body. It is lost as urine, faeces, sweat and breath.
What are the sources of Vitamin C? Where is it used? What is the deficiency of Vitamin C?
Found in citrus fruits like oranges and lemons. It helps bond cells together, and we use it to form and important protein used to make blood vessels, skin and tendons. Deficiency of vitamin C leads to scurvy.
Scurvy - - bleeding in parts of the body, particularly gums. Gums can get inflamed, teeth can fall out.
What are the sources of Vitamin D? Where is it used? What is the deficiency of Vitamin D?
It is manufactured in your body when exposed to sunlight. Needed for the small intestine to absorb calcium, regulates deposition of calcium in bone cells. Deficiency of this results in a lack of calcium in bones causing rickets in children. In adults it gives rise to osteomalacia.
Rickets - Bones fail to grow properly and become soft, when children start walking, bones bend with the weight of the body. We can prevent rickets by eating foods rich in vitamin D: fish liver oil, butter, eggs, milk.
What are the characteristics of Vitamins?
Essential in small quantities
Works with enzymes to control chemical reactions in the body
Cannot be digested or broken down by enzymes
Cannot be used to build up body structures
What are the sources of Iron? Where is it used? What is the deficiency of Iron?
It is required to make the blood protein- haemoglobin. Foods rich in iron are: cocoa, meat and liver. A lack of iron in the diet results in a disease called anaemia.
Anaemia - lack of iron leads to a reduction in the number of red blood cells. Main symptoms include tiredness and lack of energy, shortness of breath, heart palpitations and pale complexion
What are the sources of Calcium? Where is it used? What is the deficiency of Calcium?
Deposited in teeth and bones, giving them their hardness. Present in the blood plasma, it also plays an important role in blood clotting. Lastly, it is involved in complex chemical reactions that enable muscle contraction and transmission of nerve impulses.
Rich sources are: milk, cheese, fish, green vegetables.
Deficiency of calcium leads to rickets.
What is Ingestion?
the taking in of substances (food and drink) into the body through the mouth
What is digestion?
the breaking down of large insoluble molecules into small soluble molecules so that they can pass through the gut wall into the blood
What is Absorption?
the movement of digestive food molecules and ions through the wall of the intestine into the blood
What is Assimilation?
the movements of digestive food molecules into the cells of the body where they can be used, becoming part of the cells
