RD Exam Practice Questions | 250 Questions with 100% Correct Answers | Updated & Verified | 112 Pages

Which of the following carbohydrates is not a monosaccharide? a. fructose b. galactose c. maltose d. glucose - C. Maltose Fructose found in fruit and is sweetest of all monosaccharides. Galactose is derived from hydrolysis of lactose (milk sugar) during digestion. Not found freely in foods. Glucose is the primary monosaccharide used for energy. Generally part of sucrose (disaccharide; glucose + fructose) or linked to lactose to form galactose (disaccharide; glucose + lactose). When glucose is linked to another glucose molecule, it forms maltose and is considered a disaccharide. Which of the following statements about glycogen is true? a. Glycogen is a long-term energy source. b. The liver stores approximately 100 grams of glycogen. c. Glycogen is stored primarily in the liver but also appears in skeletal and heart muscles. d. The glycogen found in skeletal muscles is catabolized for use anywhere in the body. - B. The liver stores approximately 100 grams of glycogen. glycogen is short-term carbohydrate storage for the body. ~100g of glycogen is stored in the liver, which when catabolized provides ~400 kcals. About 300-400g of glycogen is stored in the skeletal muscles, which yields less than 1600kcal. Glycogen is NOT stored in the heart muscle. The glycogen stored in the liver provides energy anywhere in the body, whereas the glycogen stored in the skeletal muscles provides energy only to skeletal muscle cells. The amount of stored glycogen is sufficient to sustain an 70kg male for approximately 1 day. Which of the following statements about controlling blood glucose levels is false? a. Beta cells in the islets of Langerhans produce insulin, which is released when blood glucose levels rise in response to a meal.b. Alpha cells in the islets of Langerhans secrete glucagon when the patient is fasting, which stimulates the liver to break down glycogen to maintain blood glucose levels in the normal range of 80 to 120 mg/dl. c. The adrenals secrete epinephrine and norepinephrine when the patient is fasting, which stimulates muscles to release glycogen to maintain blood glucose levels. d. Glucocorticoids, such as cortisol stimulate glycolysis to increase blood glucose levels. - D. Glucocorticoids, such as cortisol, stimulate glycolysis to increase blood glucose levels. Blood glucose levels are influenced by hormones, drugs, and vagus nerve activity. The islets of Langerhans in the pancreas produce insulin when the patient feeds and glucagon when the patient fasts. In the postprandial period beta cells release insulin to normalize blood glucose levels. In the fasting state, alpha cells release glucagon to stimulate glycogenolysis, which is glycogen breakdown. Epinephrine and norepinephrine increase glucose levels during stress by promoting catabolism of muscle cells for glycogen and adipose cells for triglycerides. Glucocorticoids increase blood glucose levels by stimulating gluconeogenesis, not glycolysis. Glycolysis is the breakdown of glucose. Gluconeogenesis is glucose formation, which occurs mainly in the liver. Glycolysis and gluconeogenesis do not occur at the same time. Body fat performs all of the following except: a. Provides a concentrated source of energy b. Protects bones and internal organs by cushioning them and regulating their temperature. c. Provides a source of eicosapentaenoic (EPA) and docosahexaenoic (DHA) essential fatty acids. d. Aids in absorption of the fat soluble vitamins A,D,E, and K