Unit 1: Humans as functioning organisms

1.4 NUTRIENT PROCUREMENT

a) Cells require nutrients – amino acids, simple sugars, fatty acids, vitamins and minerals to supply energy for metabolism and matter for synthesis.
b) The derivation of these nutrients from proteins, carbohydrates and lipids.
c) Concept of balanced diet, dietary defects.
d) The simple chemistry of carbohydrates, lipids and proteins at the level of their major building blocks, i.e. glucose, amino acids, fatty acids and glycerol.
e) Mechanical digestion, the four types of teeth.
f) Chemical digestion by enzymes; names (use source terms e.g. salivary amylase) source, substrate and product.
g) The structure of the alimentary canal in relation to its functions: secretion, absorption, peristalsis and defecation.
h) The role of the circulatory and lymphatic systems in absorption and transport of products of digestion via the liver to the tissues.

i) Energy values of foods.
j) Variations in dietary needs in infancy, adolescence and pregnancy.
k) Tooth structure, deciduous and permanent teeth, dental formulae, dental diseases.
l) Anorexia nervosa, ulcers, indigestion, constipation and bowel cancer.
m) Food poisoning and health regulations for the food industry.

Unit 1: Humans as functioning organisms

General objectives

On completion of Unit 1, you should be able to:

• describe human biology as a multidisciplinary study of humans at the levels of populations, individuals, systems, tissues and cells
• describe the general principles of biological classification and those features that characterise humans as mammals, primates and hominids
• recognise that an upright stance, uniquely intelligent brain and highly manipulative hands distinguish humans from other primates
• explain that human posture, object manipulation and locomotion involve the co-ordinated activity of muscular and skeletal systems
• describe the body’s requirements for nutrients and oxygen to supply energy and matter for activity, growth, repair and replacement
• explain how the digestive system facilitates the absorption of nutrient molecules
• explain how the respiratory system is adapted for efficient uptake of oxygen and release of carbon dioxide
• describe how the circulatory system transports nutrients and oxygen to the cells, waste material and carbon dioxide from the cells, and acts as a link between all body tissues and major organ systems
• describe the beneficial effects of exercise on the musculo-skeletal, respiratory and circulatory systems
• describe the major cardiovascular and respiratory diseases and explain the factors which increase their risk of occurrence
• accurately measure time, length, mass, volume, temperature and pulse rate
• use food composition tables to analyse a diet and demonstrate competence in conducting chemical tests on foods
• demonstrate an awareness of basic first aid skills associated with bone fractures, haemorrhage and resuscitation
• demonstrate a positive attitude towards adopting a health sustaining lifestyle.

Unit 1 is broken up into the following units. The content covered in each of these topics is listed below. The points in normal type can be expected to be covered in tests. The points typed in italics at the end of each topic are not always covered and if they are, they are assessed in work other than tests.

1.1 Posture and Movement
1.2 The Primates
1.3 Gas Exchange
1.4 Nutrient Procurement
1.5 Internal Transport
1.6 Exercise and Cardiovascular Diseases

1.4 NUTRIENT PROCUREMENT: various links

Glycemic Index (GI)

Cereal Nutrition Information