Transcript Vitamins
Food Science lesson 3: Building Bodies with Food Hunter-gatherers – life as it used to be Take-home thought from Lesson 2: Did you think about this? Our bodies are built to resist: •Danger •Physical fatigue •Food scarcity by making stress hormones and retaining fats Most people today What are we made of? The pieces of “lego” that make up our bodies are called PROTEINS. “PrÔtos” in Greek means “first”. All living things are built first of all from proteins. Proteins are long chains of amino acids, the basic building blocks of our organisms. There are 20 different protein-forming amino acids, usually linked together like a necklace. Once these chains are linked together, they coil in a spiral shape to form a protein There are about 20 amino acids involved in the construction of proteins. Alanine Arginine Asparagines Aspartic acid Cysteine & cystine Glutamic acid Glutamine Glycine Histidine Isoleucine Leucine Lysine Methionine Phenylalanine Proline Serine Threonine Tryptophan Tyrosine Valine Our bodies can manufacture/synthesize some amino acids, but not all of them. So we get some “essential” amino acids by breaking down the proteins in our food So what foods give us proteins? Meat, fish, milk, eggs and cheese are rich in protein Legumes, pulses and nuts are also excellent sources of protein There are also good plant sources of But proteins are NOT just building blocks. Apart from providing structure and growth for our body, they also carry out functions of repair, protection, and regulation. For example: Telomerase Most enzymes, which help regulate chemical reactions, are proteins The actin and the myosin that form our muscles also have the function of contraction: Hemoglobin (a protein) binds oxygen to blood, transporting it to every part of the body Antibodies are made of proteins (protection) Red blood cells Proteins containing phenylalanine help your memory Antibodies attacking a virus Some hormones are also proteins . Hormones regulate so many things in our bodies! appetite reproduction digestion attraction happiness fear growth sleep stress Regulation in our bodies is also carried out by two other nutrients in very small quantities, for this reason they are known as “micronutrients”: Vitamins: organic substances Minerals: inorganic substances Help regulate many processes Are essential (cannot be synthesized in our bodies) Can be damaged by: Minerals compose about 6% of our bodies: in solid forms - calcium in our bones and teeth dissolved in liquids. heating (cooking), exposure to sunlight, processes of conservation. They also have functions of regulation. Most vitamins and minerals are eliminated daily by our bodies so we must eat foods that contain them every day. Here are some of the most important minerals and their functions: Mineral(s) Function(s) Sources Details Calcium Structure of bones and teeth muscle contraction blood coagulation milk, cheese, dairy products, also leafy green vegetables It is the most abundant mineral in our body. It requires the presence of Vitamin D to be correctly absorbed in the intestine Sodium, Potassium & Chloride regulate water balance in the cells play important role in transmitting nerve signals Potassium: bananas, cantaloupe, prunes, raisins Sodium and Chloride are usually found together as table salt Magnesium regulates various biological processes involved in muscle contraction Iron Essential constitutive element for production of hemoglobin, the protein that transports oxygen in the blood Seeds, whole Is magnesium magnetic? grains, nuts, leafy greens, bananas, (only when it’s next to another magnet) chocolate Meat, eggs, fish, legumes, leafy greens, some fruits and vegetables It is easier for the body to assimilate iron from animal sources. The presence of Vitamin C helps in the assimilation of iron. Here are some photos of iron, calcium, potassium and magnesium Vitamins are divided into two groups Hydrosoluble: Soluble in water Liposoluble: Soluble in lipids (fats) Vitamins B (B-group) and C Vitamins A, D, E and K These vitamins dissolve in water (in the liquids inside and around the cells): they cannot be stored in the body because they are eliminated in sweat and urine, so they must be part of our daily diet. There are about 12 different B vitamins These vitamins dissolve in fats and tend to accumulate in the body’s tissues. Vitamin D can be directly absorbed from sunlight by our skin. Sometimes people who live in polar regions, especially at the North Pole, cannot get enough Vitamin D. Vitamins help growth, protect the skin, reinforce the nervous system, increase resistance to infections, help prevent anemia and tumors. In Italy today, our diets generally supply the daily requirements of all vitamins, so it is very rare to suffer from vitamin deficiency. In fact, 1 ½ oranges supply enough vitamin C for a day, and 2 micrograms of Vitamin B12 is all we need daily. Some liposoluble vitamins seen under the microscope Vitamin A Vitamin D Beta-carotene (precursor Vitamin A) Vitamin E Vitamin K Liposoluble Vitamins: Vitamin Characteristics Food sources Functions Deficiency Vitamin A (Retinol) Beta-carotene is a precursor of Vitamin A Yellow and orange fruit and vegetables; for example carrots Improves eyesight, helps growth and immune system Night blindness, problems with color perception Vitamin D It is produced by our skin using the light of the sun Eggs, milk and dairy products, cod liver oil Regulates calcium absorption in the intestine Rickets: bone deformation It is an antioxidant Wheat germ, vegetable oils, fruit Protects cell membranes; is good for Skin Green vegetables, cereal, meat, dairy products Necessary for coagulation of blood (Cholecalciferol Ergocalciferol) Vitamin E (Tocopherol) Vitamin K It is produced (Phytonadione) by bacteria in the intestine Anemia early aging Hemorrhages Some hydrosoluble vitamins from the B group seen under the microscope B2 B1 B6 B5 B12 B9 Some of the Hydrosoluble Vitamins Vitamin Characteristics Food Sources Functions Deficiency Vitamin B1 (Thiamine) It is also produced by bacteria in the intestine Whole cereals, brewer’s yeast, almonds, meat, eggs, milk, fish Regulates the metabolism of sugars Beriberi – disease of nervous system and digestive cells Vitamin B2 (Riboflavin) It is damaged by heat (cooking) and sunlight Legumes, fruit, whole cereals, egg yolk, meat Helps in processes of energy metabolism, protects skin, protects against infections Halts growth; skin diseases Meat, fish, legumes, brewer’s yeast Helps in processes of energy metabolism, protects skin and nervous system Pellagra: impacts skin and provokes dementia Vitamin B3 (Niacin) Vitamin B9 (Folic Acid) It is damaged by heat (cooking) and sunlight Green and leafy green vegetables, liver, brewer’s yeast Synthesis DNA, production red blood cells (with Vit. B12), needed in pregnancy Severe anemia, halted growth, fetal malformations Vitamin B12 (Cobalamin) It is damaged by sunlight Meat, fish, milk, eggs (not in vegetables) Cell growth and renewal; helps B9 to synthesize red blood cells Severe anemia Vitamin C (Ascorbic Acid) It is damaged by exposure to air, heat (cooking) and sunlight Fresh fruit and vegetables, especially citrus and kiwi Anti-oxidant; helps synthesize proteins, protects from infections and hemorrhages Scurvy, a serious illness that causes hemorrhages and general deterioration Several views of the incredibly beautiful Vitamin C (hydrosoluble) seen under the microscope Last but not least: don’t forget water! We are Water: 65% body weight We are Water: The water we drink has dissolved minerals Every day we lose and replace 2,5 liters of water. Where biochemical reactions happen Transports nutrients Maintains body temperature Take-home task: Can you write a balanced menu? In English??