Nursing 105

Essentials of Nursing Study Guide

©2018 Achieve Page 11 of 160 (single molecules) and glucose. Fructose and galactose, which require no digestion and are used readily by the body for energy, are also a source as well as disaccharides (double molecules) and lactose which is a combination of glucose and galactose which is found in milk. Carbohydrates may be simple or complex. Simple carbohydrates are single or double sugars. Complex carbohydrates are composed of many single sugars joined together (starch, dietary fiber, glycogen). Starches are polysaccharides which are branched chains of glucose molecules. Fiber is a complex carbohydrate derived from plants, not digestible but supplies bulk to the body. • Functions: Carbohydrates are the primary source of energy for the body. They spare proteins from being used for energy, allowing them to build and repair body tissues. Carbohydrates are stored in the body as glycogen or fat. Carbohydrates are needed to oxidize fats completely and for the synthesis of fatty acids and amino acids. The Six Essential Nutrients Water Water is the most important nutrient. The daily requirements are 1,000mL of water to process 1,000 kcal eaten. The human body is composed of 46-60% water. Age, gender, and body fat influence the amount of water in the body. Infants have the highest percentage (70-80%) of body weight; whereas, the water percentage in a 60-year-old is about 50% of body weight. Fat tissue contains no water and lean muscle does, so an obese patient has a reduced percentage of water. The average adult needs 2500ml of water daily. About 1500ml is drunk, an additional 750ml comes from food, and 200ml from the metabolism of food. • Classification and Sources: Liquids consumed (water, coffee, juice, tea, milk, soft drinks); foods consumed (especially fruits and vegetables) • Functions: The functions of water are to act as a solvent (dissolves substances to form solutions) and a transporter (carries nutrients,wastes, etc. throughout the body). Water is a regulator of body temperature. It is also a lubricant as it aids in providing smooth movement for joints and is a componentof all cells. Hydrolysis is the process where water is used to break apart substances, especially during metabolism. • Digestion, Absorption and Storage : Water is not digested. It is absorbed and used by cells. The body loses water in four ways: urine, feces, perspiration and respiration. • Signs of Deficiency : Signs of abnormal water loss include profuse sweating, vomiting, diarrhea, hemorrhage, wound drainage (burns), fever, and edema. A deficiency of water is called dehydration. Prolonged dehydration results in death. Carbohydrates Carbohydrates are made up of carbon, hydrogen, and oxygen. They are the major source of food for all bodies. The daily requirements are 50% to 60% of an individual’s kcal intake per day. • Classification and Sources: Sources are sugars, including monosaccharides