NUTRITION

• Unit Expected Outcomes


  • 01 Acquire knowledge on the biological basis of nutrition
  • 02 Specify the mechanism of hormone secretions according to its location
  • 03 Point out examples of pathological conditions associated with hormones
• BCHM 113 Biochemistry
• 2nd Semester AY 2021-22
• Natural Science Department College of Arts and Sciences Our Lady of Fatima University
• Nutrition


  The science of nutrition focuses on the study of food, water, and other nutrients and the ways in which they are used by living organisms
• Nutrients


  Necessary for the body to function and remain healthy
• Macronutrients


  • Carbohydrates
  • Proteins
  • Lipids
• Macronutrients


  Needed in large amounts (gram quantities) because they provide energy and materials required to build and repair tissues
• Micronutrients


  • Vitamins
  • Minerals
• Micronutrients


  Required in small amounts (milligram or microgram quantities), many are used in enzymes
• Water


  45-75% of human body mass is water
• Fiber


  Indigestible plant material made mostly of cellulose, helps maintain digestive health by providing roughage to stimulate contraction of the intestines and help pass food through the digestive system
• Daily Values (DV)


  Nutritional guidelines established by the FDA for use on food labels
• Daily Values (DV)


  • Reference Daily Intakes (RDI) - proteins and 19 vitamins and minerals
  • Daily Reference Values (DRV) - other nutrients and food components
• Carbohydrates


  Provide energy for body functions and useful materials for the synthesis of cell and tissue components
• Carbohydrates


  • Simple carbohydrates - monosaccharides and disaccharides such as glucose, fructose, sucrose, etc.
  • Complex carbohydrates - polysaccharides amylose and amylopectin (starch)
  • Cellulose - complex carbohydrate that serves a nonnutritive role as fiber
• Current recommendations are that about 58% of our daily calories should come from carbohydrates; currently, about 46% of the typical American diet comes from carbohydrates, and much of that comes from simple sugars rather than from complex carbohydrates
• Lipids


  About 95% of the lipids in foods and in our bodies is in the form of triglycerides
• Triglycerides


  • Containing a high concentration of unsaturated fatty acids are liquids at room temperature (oils)
  • Containing a high concentration of saturated fatty acids are solids at room temperature (fats)
• Lipids


  Provide a concentrated source of energy (9 Cal/g), proteins and carbohydrates provide 4 Cal/g
• Lipids


  Contain some fat-soluble vitamins and help to carry them through the body
• Lipids


  Improve the texture of foods, absorb and retain flavors, and are digested more slowly than other foods, prolong the feeling of satiety (satisfaction and fullness after a meal)
• Linoleic and linolenic acids

  Essential fatty acids that cannot be synthesized in the body, and must be obtained from the diet
• Sources of linoleic and linolenic acids

  • Corn, cottonseed, soybean oils, and wheat germ
• The average American receives about 42% of the calories in their diets from fat, while the recommendation is about 30%
• Proteins


  Necessary for production of new tissue, maintenance and repair of cells, production of enzymes, hormones, and other important nitrogen-containing compounds
• Proteins


  Provide 4 Cal/g of energy
• Amino acids


  Proteins are broken down into amino acids on digestion, which are then absorbed into the body's amino acid pool
• Essential amino acids


  Must be obtained from the diet
• Complete proteins


  Contain all of the essential amino acids in the proportions needed by the body
• Vitamins


  Organic micronutrients that the body cannot produce in amounts needed for good health
• Vitamins


  • Water-soluble
  • Fat-soluble
• Water-soluble vitamins


  Highly polar, function as coenzymes (except Vitamin C), excess amounts are usually removed by the kidneys
• Fat-soluble vitamins


  Nonpolar molecule structure, dissolve only in nonpolar solvents, care must be taken to avoid overdoses since they are not eliminated as readily and are stored in the liver and fatty tissues
• Major minerals


  • Found in the body in quantities greater than 5 grams, inorganic structural components of bones and teeth (Ca, P), or needed in large amounts for the regulation of fluids and the transmission of nerve impulses (Na, K)
• Trace minerals


  • Found in the body in smaller amounts, components of vitamins, enzymes, hormones, or specialized proteins