Nutrition Nutrition is the study of how food affectsthe function of living organisms. Food contains nutrients. Nutrients provide the energy and materialsorganisms need. If organism’s cells are not provided withnutrients, the cells will not functionproperly. Poor diet = poor cells
Six Categories of NutrientsEnergy Suppliers Carbohydrates Lipids ProteinsNon-Energy Suppliers Water Vitamins Minerals
Carbohydrates Glucose is main source of carbohydratesfor animals. Glucose is easily converted to ATP. Glucose is found in fruits, vegetables,grains, and dairy foods. Many foods contain cellulose also knownas “fiber.” Important for helping push foodthrough the digestive tract. Energy from food is measured in“calories.”
Lipids Provide twice as much energy as carbohydrates. Important for…1) Making cell membranes2) Hormone production3) Myelin production4) Protect organs and insulate body Take long time to digest. Too much fat in diet= excess energy = fatdeposits. Saturated fats (solid, contain single bonds)contain LDL cholesterol and build up on arteries.
Proteins Proteins made of amino acids. 20 different amino acids. Body can make 12/20 amino acids. The other eight must come from food arecalled “essential amino acids.” Proteins are materials needed for…1) growth and repair.2) skin and muscles.3) regulatory (enzymes- insulin) and transportfunctions (hemoglobin– RBC).
Water Most important nutrient. Lubricates areas of body (blood, lymph,plasma, etc.) Coolant for body. Solvent for digestion. Provides fluid environment for cells. Body needs intake 1L of water a day.
Minerals Inorganic (not made by living things). Plants absorb minerals. Animals eat plants to get minerals. Minerals are only needed in trace amountsby the body. Iron (hemoglobin RBC) Calcium (bones and teeth) Sodium/Potassium (nerve and musclefunction) Magnesium/Zinc/Iodine
Vitamins Organic (made by living things). Help regulate body processes. Most obtained from food. Vitamin K- made by bacteria in digestive tract. Vitamin D- synthesized by skin cells whenexposed to sunlight. 2 types vitamins…1) Fat soluble- can be stored in fattytissues for future use (A, D, E, K)2) Water soluble- dissolve in water and cannot be stored by body (C, B)
Importance of Various Vitamins A, C, D, E, K, Folic Acid, B12Helps RBC mature
The Digestive System System is responsible for breaking down foodso that nutrients can be absorbed by thebloodstream. The “alimentary canal” is the pathway whichfood travels while it is digested.
The Alimentary Canal Mouth Esophagus Stomach Small intestine Large intestine Rectum* The liver, pancreas, and gallbladder are parts ofthe digestive system but are not parts of thealimentary canal.
The Mouth Chemical digestion –saliva containsenzyme amylase that digestscarbohydrates (starches) Mechanical digestion- chewing
Esophagus Tube from back throatto stomach. Trachea (lungs) andesophagus are next toeach other. Epiglottis prevents foodfrom going down thewrong tube. Peristalsis- muscularcontractions pushesfood down esophagus.
Small Intestine 20 ft. Remaining carbohydratesand proteins are brokendown. All lipids are digested here. Connected to liver andpancreas.
Liver and PancreasLIVER JOBS Makes and secretesbile (needed digestlipids). Bile is stored in thegall bladder. Detoxifies drugs andalcohol.PANCREAS JOBS Regulates bloodsugar. Secretes digestiveenzymes into smallintestine. Neutralizes stomachacid as it enters thesmall intestine(bicarbonate).
Small Intestine (cont.) After all nutrients aredigested, they areabsorbed. This is themajor job of thisorgan. S.I. contains lots ofcapillaries. Mesentary.
Large Intestine All proteins,carbohydrates, andlipids have beenremoved from food bythe time it gets here. Water is absorbed(diarrhea). Vitamins are absorbed. Feces is undigestedfood passes out rectumand anus.