Nutrition in Humans

Nutrition in Humans

1NutrientsPart INutrients are the usable portions of foodsWhat are nutrients used for?Energy Sources Building or Repair of cell structure Regulate metabolic processes26 Main GroupsCarbohydrates (bread, pasta, potatoes, candy)Proteins (beef, fish, milk, peas, nuts)Fats & Oils (butter, bacon, vegetable oil)Water (most foods contain water)Minerals (calcium, iron, sodium, chlorine)Vitamins ( A, B1, B2, Niacin, B12, C, D, K)

3Which are organic and which are not?OrganicCarbohydratesProteinsFats N OilsVitaminsInorganicWaterMinerals

4What about What we cant digestRoughage: indigestible foodExamples: fibrous matter (cell wall) in fruits, vegetables, and whole grainsBenefit: provides bulk to be worked on by muscles, keeps things moving forward

5CarbohydratesSubunit: SaccharidesMonosaccharides:1 (simple sugars, glucose)Disaccharides: 2 (sucrose and maltose)Polysaccharides: 3 or more (Starch in plants and Glycogen in animals)

6Regents QuestionMost of the starch stored in the cells of a potato is composed of molecules that originally entered these cells as(1) enzymes(2) simple sugars(3) amino acids (4) minerals 7Why can glucose diffuse through the cell membrane and Starch can not?Glucose is a monosaccharide and much smaller than the polysaccharide of Starch

8ProteinsSubunit: Amino Acids (NH2 = amino group COOH = carboxyl acid)

9Regents QuestionTwo proteins in the same cell perform different functions. This is because the two proteins are composed of(1) chains folded the same way and the same sequence of simple sugars(2) chains folded the same way and the same sequence of amino acids(3) chains folded differently and a different sequence of simple sugars(4) chains folded differently and a different sequence of amino acids

10Regents QuestionWhich statement concerning proteins is not correct?(1) Proteins are long, usually folded, chains.(2) The shape of a protein molecule determines its function.(3) Proteins can be broken down and used for energy.(4) Proteins are bonded together, resulting in simple sugars.11ProteinsThe Human body need 20 different types of Amino Acids12 of the 20 humans can synthesize (produce)8 of the 20 humans can not, these 8 are called Essential amino acids (Isoleucine, Leucine, Lysine, Methionine, L-Phenylalanine, Threonine, Tryptophan and Valine)

12If proteins come mostly from meat, how do vegetarians get the 8 essential?There are 2 types of proteinsComplete Protein: contains all essential amino acidsIncomplete Protein: missing one or more essential amino acidsSo to answer the question: a vegetarian can eat a combination of incomplete proteins to provide all essential amino acids (ex. Rice and Beans)13What happens if you are missing one of the essential 8?You would get a protein-deficiency disease.Example: Populations in Africa diet consist of cornmeal (incomplete protein) lacks Tryptophan. These children have a disease called Kwashiorkor (tired and abnormal growth)

14Fats (Lipids)Synthesized in body from Fatty acids and GlycerolRepresents stored energyTogether with proteins synthesize the cell membrane

15Fats (Lipids)

16Bad FatSaturated Fat: Usually solid at room temperature, No Double Bonds, lead to cholesterol deposits in blood vessels

17Good FatUnsaturated Fat: consists of oils (liquid at room temperature), one or more Double Bonds

18MineralsImportant inorganic material (helps in structure of cells and tissues)Calcium (Ca): strong teeth and bones, milk & eggsIron (Fe): helps in formation of red blood cells (red pigment), liver, meats & vegetablesSodium (Na): needed for proper cell function, table salt19VitaminsLike minerals, perform many functionsEspecially important growth of childrenIn adults repair and maintain healthy body functionsUnable to be synthesized by humans

20VitaminsA: healthy eyes & skin, green and yellow vegetablesB1: growth and appetite, meats, seafood, milkB12: production of red blood cells, liver & green vegetables

C: healthy teeth, gums, and blood vessel repair, fruitsD: growth and maintenance of bones, produced in skin exposed to sunlight & fortified milkK: blood clotting, liver function, synthesized by bacteria in body21WaterExcellent solvent (dissolves many compounds)Main component of fluid transport (blood)Many chemical reactions take place Lubricant for joints and digestive systemCools body by sweat evaporationLost by breathing, urination, and elimination

22What is a calorie?The amount of heat needed to raise 1mL of water by 1 C0Unit of measurement for energy value in foodCalorimeter: tool used to measure calories in foods

23Food AdditivesSaccharin: artificial sweetenerNitrites: protect food from bacterial decay and provide red color, found in bacon hotdogs, and deli meatsMonosodium glutamate (MSG): flavor enhancer

24The Digestive System PartII

25What is the Digestive System?The alimentary canal (coiled tube which ingested materials move in one direction) and digestive glands make up the digestive systemHydrolysis

26What are the functions of the Digestive System?There are 3 main functions of the Digestive systemIngest foods (eat)Breakdown foods so nutrients can be absorbedEliminate (egestion) what can not be digested

27Regents QuestionWhich order of metabolic processes converts nutrients consumed by an organism into cell parts?(1) digestion absorption circulation diffusion synthesis(2) absorption circulation digestion diffusion synthesis(3) digestion synthesis diffusion circulation absorption(4) synthesis absorption digestion diffusion circulation28When does digestion start?As soon as we place food in our mouth.Mechanical and Chemical digestion occursMechanical digestion = ChewingChemical digestion= Saliva

29Digestion in the MouthMucus Glands: lubricant for food in the form of mucus (allows food to travel smoothly)Saliva Glands: contains amylase (enzyme) which breakdown starch into maltosePolysaccharide (starch) to a Disaccharide (maltose)

30From your mouth to your EsophagusSwallowing: coordinated reflex action that moves food to the esophagusDuring swallowing the trachea (windpipe) moves upward against the epiglottis (flap)

31EsophagusFood is moved from the mouth to the stomachThe movement is called Peristalsis: muscle contractions and relaxations (moves in waves, like pushing a tube of toothpaste)

32StomachMuscular organ that churns food and initiates protein digestion (balloon like, expands when full and shrinks when empty

33Stomach (Gastric Juices)Gastric Glands: located on the inner lining of the stomachContains peposinogen and hydrochloric acid HCl (keeps pH at 2 and kills off bacteria)Acidic environment favorable for pepsin (enzyme) to breakdown proteinsRennin: an enzyme that changes liquid proteins into a solid state (curdles milk proteins)34Stomach (final product)The process takes about 2 to 24 hours (depending of the foods present)Chyme: mixture of saliva, gastric juices, and water

35Which organs of the digestive system never in contact with food?Liver: secretes bile (aids in digestion of fats) emulsification (makes small globules of fat from large ones)Gallbladder: bile is stored here and transport to small intestine via bile ductPancreas: pancreatic juices (enzymes)Proteases= protein digestionAmylase= carbohydrate digestionLipase= fat digestion

36Liver, Gallbladder, & Pancreas

37Small IntestineLongest part of digestive tract (7m)Called small because of diameter (6.5 cm)Most digestion and absorption occurs here

38Absorption in Small IntestineVilli: tiny projectiles on the inner surface of small intestineThere are enough villi in your small intestine to cover a tennis court (large surface area)

39How do the nutrients leave the Small intestine?DiffusionVilli only 1 cell thickAmino acids and simple sugars enter capillariesFats enter lacteal (lymph vessel)

40Small Intestine is an excellent example of adaptationMuscles contract to mix liquids and bring them to villiGreat length and folds provide large surface area for absorptionVilli provides large surface area (ten times greater than skin)Thin membrane allows for easy diffusion of nutrients

41Large IntestineNo digestion occurs hereWater absorptionContains bacteria which produce vitaminsEating yogurts help replenish lost bacteria

42Time of DigestionMouth: 5-10 secEsophagus: 10 secStomach: 2 to 24 hoursSmall Intestine: 3 to 4 hoursLarge Intestine: 18 hours to 2 Days

43Elimination (egestion)Feces or waste is stored in the rectum (lower part of large intestine)Feces leaves our body through the anus

44Problems in DigestionWhat do you call a hole in your stomach?Ulcer: occurs when HCl (hydrochloric acid) and pepsin are in direct contact with the stomach lining. (little to no Mucus present)

45Why cant I Poop?Constipation: occurs in the Large intestine, happens when too much water is absorbed and the feces hardensWhat is the opposite of constipation?Diarrhea: Not enough water in absorbed in the Large intestine and the feces remains soft and watery (may be a symptom of infection or stress)

46Appendicitis Inflammation of the appendix (located where the small intestine meets the large intestine)Symptoms: abdominal pain, nausea, and feverSurgery usually needed to remove before rupture

47GallstonesHarden deposits that form in the gallbladder (deposits may block the bile duct, causing pain)

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