Diet And Digestion
Aperçu
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.
Objectifs
- 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
Carte mentale
Ce theme est schematise pour montrer comment les idees se relient.
Ouvrez la carte mentale dans l'application
Cartes memoire
Entrainement rapide sur les faits evalues dans ce theme.
Entrainez-vous sur ces cartes dans l'application
Note de cours
Fiche complete disponible sur l'application Green Bridge
Installez l'application Green Bridge CBT sur votre telephone ou votre ordinateur pour acceder a toute la bibliotheque IGCSE : sujets d'examen, baremes, cartes mentales, fiches memo et lecons audio.
Évaluation de la leçon
Félicitations, vous avez terminé la leçon sur Diet And Digestion. Maintenant que vous avez exploré le concepts et idées clés, il est temps de mettre vos connaissances à l'épreuve. Cette section propose une variété de pratiques des questions conçues pour renforcer votre compréhension et vous aider à évaluer votre compréhension de la matière.
Vous rencontrerez un mélange de types de questions, y compris des questions à choix multiple, des questions à réponse courte et des questions de rédaction. Chaque question est soigneusement conçue pour évaluer différents aspects de vos connaissances et de vos compétences en pensée critique.
Utilisez cette section d'évaluation comme une occasion de renforcer votre compréhension du sujet et d'identifier les domaines où vous pourriez avoir besoin d'étudier davantage. Ne soyez pas découragé par les défis que vous rencontrez ; considérez-les plutôt comme des opportunités de croissance et d'amélioration.
- 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
Travaillez ces questions dans l'application
Travaillez ces questions dans l'application
Livres recommandés
Pour aller plus loin, ressources libres
-
Section de manuel
Nutrition and Energy Production
Explain why an animal’s diet should be balanced and meet the needs of the body
"Biology: Nutrition and Energy Production" by OpenStax, OpenStax, Rice University, licensed under CC BY 4.0 (https://creativecommons.org/licenses/by/4.0/). Source: https://openstax.org/books/biology/pages/34-2-nutrition-and-energy-production. Access for free at https://openstax.org/books/biology/pages/1-introduction
-
Section de manuel
Digestive Systems
Explain the processes of digestion and absorption
"Biology: Digestive Systems" by OpenStax, OpenStax, Rice University, licensed under CC BY 4.0 (https://creativecommons.org/licenses/by/4.0/). Source: https://openstax.org/books/biology/pages/34-1-digestive-systems. Access for free at https://openstax.org/books/biology/pages/1-introduction
Publiées par d'autres organisations sous licence libre, créditées comme elles le demandent. Les liens ouvrent leurs sites.
Pratiquez des questions blanches
Vous voulez vous entraîner sur des questions blanches sur Diet And Digestion ? Téléchargez l'application Green Bridge CBT pour accéder à des questions blanches et à des évaluations complètes sur ce sujet.
Téléchargez l'application sur Google Play.
Tout ce dont vous avez besoin pour exceller au JAMB, WAEC et NECO.
