IB Exam (Option D)
6.1 Human Nutrition
Understandings:
U1 Essential nutrients cannot be synthesized by the body; therefore they have to be included in the diet
U2 Dietary minerals are essential chemical elements.
U3 Vitamins are chemically diverse carbon compounds that cannot be synthesized by the body
U4 Some fatty acids and some amino acids are essential.
U5 Lack of essential amino acids affects the production of proteins.
U6 Malnutrition may be caused by a deficiency, imbalance or excess of nutrients in the diet.
U7 Appetite is controlled by a centre in the hypothalamus
U8 Overweight individuals are more likely to suffer hypertension and type II diabetes
U9 Starvation can lead to breakdown of body tissue.
Application
A1 Production of ascorbic acid by some mammals, but not others that need a dietary supply.
some mammals can produce Vitamin C
others cannot
those who cannot must receive Vitamin C externally
A2 Cause and treatment of phenylketonuria (PKU).
Cause | Treatment |
|---|---|
|
A3 Lack of Vitamin D or calcium can affect bone mineralization and cause rickets or osteomalacia.
A4 Breakdown of heart muscle due to anorexia.
anorexia affects the heart via:
A5 Cholesterol in blood as an indicator of the risk of coronary heart disease
Skills
S1 Determination of the energy content of food by combustion
S2 Use of databases of nutritional content of foods and software to calculate intakes of essential nutrients from a daily diet
Nature of Science
Falsification of theories with one theory being superseded by another—scurvy was thought to be specific to humans, because attempts to induce the symptoms in laboratory rats and mice were entirely unsuccessful.
6.2 Digestion
Understandings
U1 Nervous and hormonal mechanisms control the secretion of digestive juices.
U2 Exocrine glands secrete to the surface of the body or the lumen of the gut.
U3 The volume and content of gastric secretions are controlled by nervous and hormonal mechanisms.
U4 Acid conditions in the stomach favour some hydrolysis reactions and help to control pathogens in ingested food.
U5 The structure of cells of the epithelium of the villi is adapted to the absorption of food.
U6 The rate of transit of materials through the large intestine is positively correlated with their fibre content.
U7 Materials not absorbed are egested.
Application
A1 The reduction of stomach acid secretion by proton pump inhibitor drugs.
A2 Dehydration due to cholera toxin.
A3 Helicobacter pylori infection as a cause of stomach ulcers.
Skills
S1 Identification of exocrine gland cells that secrete digestive juices and villus epithelium cells that absorb digested foods from electron micrographs.
Nature of Science
6.3 Functions of the Liver
Understandings
U1 The liver removes toxins from the blood and detoxifies them.
U2 Components of red blood cells are recycled by the liver.
U3 The breakdown of erythrocytes starts with phagocytosis of red blood cells by Kupffer cells.
U4 Iron is carried to the bone marrow to produce hemoglobin in new red blood cells.
U5 Surplus cholesterol is converted to bile salts.
U6 Endoplasmic reticulum and Golgi apparatus in hepatocytes produce plasma proteins.
U7 The liver intercepts blood from the gut to regulate nutrient levels.
U8 Some nutrients in excess can be stored in the liver.
Application
A 1 Production of ascorbic acid by some mammals, but not others that need a dietary supply.
A 2 Cause and treatment of phenylketonuria (PKU).
A 3 Lack of Vitamin D or calcium can affect bone mineralization and cause rickets or osteomalacia.
A 4 Breakdown of heart muscle due to anorexia.
A 5 Cholesterol in blood as an indicator of the risk of coronary heart disease.
Skills
S1 Determination of the energy content of food by combustion.
S2 Use of databases of nutritional content of foods and software to calculate intakes of essential nutrients from a daily diet.