Digestion and Essential Nutrients PDF

- The digestive system is responsible for the breakdown of large, complex organic materials into smaller components that are utilized by the tissues of the body. Every organ system depends on the digestive system for nutrients. - There are four components of digestion: -...

- The digestive system is responsible for the breakdown of large, complex organic materials into smaller components that are utilized by the tissues of the body. Every organ system depends on the digestive system for nutrients. - There are four components of digestion: - 1. ingestion— the taking in of nutrients - 2. digestion— the breakdown of complex organic molecules into smaller components by enzymes - 3. absorption— transport of digested nutrients to the tissues of the body - 4. egestion—the removal of waste food materials from the body Six essential nutrients to keep healthy 1. Carbohydrates 2. Proteins 3. Lipids 4. Liquids 5. Water 6. Vitamins 7. Minerals Proteins Proteins are the most complex of all nutrients. They are made up of long chains of smaller molecules called amino acids When you eat proteins, your body separates the proteins into individual amino acids so they can be rearranged and used as building blocks for human proteins protein can also be used to provide energy, and excess protein can be converted into high-energy storage molecules Carbohydrates - Carbohydrates are the main source of energy for the human body. - Carbohydrate molecules are made up of carbon, hydrogen, and oxygen. There are three main types of carbohydrates: monosaccharides - simple sugars, ring-shaped structures consisting of a single sugar molecule. (glucose and fructose) disaccharides - made up of two simple sugars joined together (lactose and sucrose) polysaccharides - complex carbohydrates, may consist of hundreds of joined simple sugars. (starch, cellulose, glycogen) Plants store carbohydrates in the form of starch (in the roots, stems, leaves, and seeds) Animals store carbohydrates in the form of glycogen (in the liver and muscle tissues). If the maximum amount of glycogen is stored, excess carbohydrates can be converted to lipids and stored as body fat. When energy is needed, glycogen is converted back into usable glucose. Cellulose is used in plant cell walls to give the plant structure. Humans cannot digest cellulose, but it provides fibre, which is an important part of a healthy diet. Fats and Lipids - Lipids provide a concentrated source of chemical energy for the body. - They help in the absorption of vitamins, are a main component of cell membranes, and serve as insulation for the body. - Fats and oils are two familiar types of lipids. - Fats and oils are made up of three fatty acids bonded to a glycerol molecule, which make up a triglyceride. Vitamins - A vitamin is a compound that an organism needs as a nutrient only in small amounts. - Vitamins are classified as either fat soluble (will dissolve in fats) or water soluble (will dissolve in water). - Vitamins A, D, E, and K are fat soluble vitamins - Vitamins B and C are water soluble vitamins Minerals - Minerals are naturally occurring elements that the body uses to carry out metabolic processes and to build or repair tissues. - calcium and phosphorus - critical in the formation of bone. - sodium - nerve impulse transmission and muscle contraction. - iron – a key component of the blood protein hemoglobin. - Other minerals, such as fluorine, zinc, and copper, are present in our bodies in trace amounts.