Diet And Digestion
Overview
A teenager, a pregnant woman and a manual labourer sitting down to the same meal do not actually need the same meal. Age, pregnancy, climate and the physical demands of a job all change how much energy and which nutrients a body requires, and getting the balance wrong for long enough produces a recognisable deficiency disease with its own set of symptoms. This topic builds the full picture: what a balanced diet supplies, how the alimentary canal breaks food down into absorbable molecules, and how the small intestine is engineered to get those molecules into the blood as efficiently as possible.
You will also meet the practical side of nutrition that Human Biology students are expected to reason about: calculating and interpreting BMI, linking obesity and high cholesterol to specific diseases, and knowing why hygienic food preparation matters at every stage from the kitchen to the gut. Expect calculation questions, structure-to-function reasoning and at least one question that asks you to identify a deficiency disease from a described set of symptoms.
Objectives
- Explain the importance of a balanced diet including the recommended dietary intake of carbohydrates, fats, proteins, vitamins A and C, calcium, iron and fibre
- Understand variations in diet related to age, pregnancy, climate and occupation
- Know the sources and functions of carbohydrates, proteins, lipids (fats and oils), vitamins A, C and D, and the mineral ions, calcium and iron
- Describe the causes and symptoms of deficiency diseases limited to scurvy (lack of vitamin C), anaemia (lack of iron), blindness (lack of vitamin A) and Kwashiorkor (lack of protein)
- Know the structures of the human alimentary canal and describe the functions of the mouth, oesophagus, stomach, small intestine, large intestine and pancreas in digestion
- Explain how food is moved through the gut by peristalsis including the role of dietary fibre in the process
- Understand the role of digestive enzymes including their site of production and action, the digestion of starch to glucose by amylase and maltase, the digestion of proteins to amino acids by proteases (pepsin, trypsin), and the digestion of lipids to fatty acids and glycerol by lipases
- Know that bile is produced by the liver and stored in the gall bladder and understand the role of bile in neutralising stomach acid and emulsifying lipids
- Understand how the structure of the villus helps absorption of the products of digestion in the small intestine
- Know the types, structure and functions of teeth, the factors that affect their growth and how to care for teeth and gums
- Understand BMI, including the calculation of BMI, and the role of obesity as a risk factor in early onset of diabetes and the significance of high cholesterol levels in atherosclerosis
- Explain the importance of hygienic methods of food preparation, cooking, storage and preservation
Lesson Note
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Lesson Evaluation
Congratulations on completing the lesson on Diet And Digestion. Now that youve explored the key concepts and ideas, its time to put your knowledge to the test. This section offers a variety of practice questions designed to reinforce your understanding and help you gauge your grasp of the material.
You will encounter a mix of question types, including multiple-choice questions, short answer questions, and essay questions. Each question is thoughtfully crafted to assess different aspects of your knowledge and critical thinking skills.
Use this evaluation section as an opportunity to reinforce your understanding of the topic and to identify any areas where you may need additional study. Don't be discouraged by any challenges you encounter; instead, view them as opportunities for growth and improvement.
- Which enzyme digests starch to maltose? A) Maltase B) Amylase C) Lipase D) Trypsin Answer: B
- A deficiency of iron in the diet causes: A) Scurvy B) Kwashiorkor C) Anaemia D) Night blindness Answer: C
- Bile is produced by the liver and stored in the: A) Pancreas B) Gall bladder C) Duodenum D) Stomach Answer: B
- Which feature of a villus increases the surface area available for absorption? A) The lacteal B) The capillary network C) Microvilli D) The muscle layer Answer: C
- A person has a mass of 80 kg and a height of 2.00 m. What is their BMI? A) 16.0 B) 20.0 C) 40.0 D) 160.0 Answer: B
Available on the Green Bridge App
Download the Green Bridge CBT app on your phone or computer to access full lesson notes, practice questions, and more.
Available on the Green Bridge App
Download the Green Bridge CBT app on your phone or computer to access full lesson notes, practice questions, and more.
Recommended Books
Practice Mock Questions
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