Y9-Food & Digestion Booklet MS

Page 1

Overview of the Food and Digestion Topic

  • Title: Answers CS Year 9 Food and Digestion

  • Date Updated: July 2021

Page 2

Lesson Overview

  • Objective: Understanding food types needed for a healthy diet, testing for various nutrients, and the role of enzymes and bacteria in digestion.

Key Areas of Study

  • What food types make up a healthy diet?

    • Keywords: Carbohydrate, Protein, Lipid, Fibre, Deficiency Disease

  • How can we test for different food groups?

    • Methods: Benedict's test, Biuret test, Iodine test

    • Tools: Calorimeter for measuring energy content

  • The role of digestive organs in breaking down food.

    • Keywords: Ingestion, Digestion, Egestion, Peristalsis

  • Understanding enzymes and bacteria in digestion.

    • Keywords: Biological catalyst

Page 3

Key Vocabulary Definitions

  • Carbohydrase: Enzyme that breaks down carbohydrates to glucose.

  • Protein: Essential for growth and repair, broken down into amino acids.

  • Fat: Lipids broken down by lipase into fatty acids and glycerol.

  • Ingestion: Intake of food into the mouth.

  • Digestion: Breakdown of food into smaller molecules.

  • Egestion: Elimination of waste (faeces).

  • Enzyme: Biological catalysts that speed up chemical reactions.

  • Peristalsis: Muscular movements that move food through the digestive tract.

  • Malnutrition: Lack of nutrients leads to health issues.

  • Deficiency Disease: Illness due to insufficient intake of nutrients (e.g., Scurvy from Vitamin C deficiency).

Page 4

Healthy Diet Components

  • A balanced diet should include the following food groups:

    • Carbohydrates, Proteins, Lipids, Vitamins, Minerals, Fibre, Water

    • Protein: For growth and repair; found in meat, eggs, and dairy.

    • Fats: Energy storage; found in oils and butter.

    • Carbohydrates: Main energy source; found in pasta and bread.

    • Vitamins and Minerals: Necessary for various bodily functions; found in fruits and dairy.

Page 5

Essential Nutrients and their Functions

  • Vitamins:

    • Vitamin C: Supports skin and gum health; found in citrus fruits.

    • Vitamin D: Strengthens bones; obtained from sunlight, eggs, and fish.

  • Minerals: Required for making red blood cells (Iron) and maintaining strong bones (Calcium).

  • Fibre: Aids in digestive health; found in plant-based foods.

Deficiency Diseases

  • Scurvy: Caused by lack of vitamin C.

  • Rickets: Due to vitamin D deficiency, causing weak bones.

  • Anaemia: Caused by insufficient iron intake.

Page 6

Nutrient Prevention of Deficiency Diseases

  • Match diseases with their preventing nutrients:

    • Scurvy - Vitamin C

    • Goitre - Iodine

    • Night Blindness - Vitamin A

    • Rickets - Vitamin D

    • Anaemia - Iron

    • Dehydration - Water

Page 7

Food Testing Techniques

  1. Testing for Starch: Use Iodine reagent. Color change indicates presence (yellow to blue/black).

  2. Testing for Sugar: Use Benedict's solution; heat to see color change (blue to brick red).

  3. Testing for Protein: Use Biuret solution; color change indicates protein presence (blue to purple).

  4. Testing for Lipids: Alcohol then water test shows milky emulsion.

Page 8

Energy Intake and Metabolic Rate

  • Individual energy needs vary by age, gender, and activity level.

  • Calorimeter Experiment: Measure energy content of food by observing temperature change in water.

Experiment Safety

  • Always wear protective goggles; never taste or eat food tested.

Page 9

Calorimeter Experiment Procedure

  1. Measure and heat water in a test tube.

  2. Weigh food and ignite it below water.

  3. Record temperature changes before and after burning.

Page 10

Calculating Energy Content

  • Use formulas involving temperature rise to calculate energy per gram of food.

  • Note potential experimental errors (e.g., heat loss).

Page 11

Understanding Obesity

  • Obesity is a non-communicable disease defined as excessive body fat (BMI > 30).

  • Linked diseases: Type II diabetes, heart diseases, hypertension.

  • Malnutrition in Obesity: Over/under-nutrition may coexist.

  • Factors Increasing Obesity: Fast food availability, sedentary lifestyles.

  • Preventative Measures: Healthy eating and regular exercise.

Page 12

Ethical Considerations in Health Studies

  • Research on junk food effects: use twins or control groups; compare health metrics.

  • Ethical issues arise concerning health risks of junk food consumption.

Page 13

Digestive System Overview

  • Organs: Oesophagus, stomach, liver, pancreas, small intestine, large intestine, anus.

  • Digestive process: Breakdown of large food molecules into smaller, absorbable ones.

Page 14

Digestive Processes

  • Mouth: Mechanical digestion via teeth; Saliva contains enzymes.

  • Stomach: Chemical digestion using hydrochloric acid and enzymes (e.g., Pepsin).

  • Small Intestine: Nutrient absorption facilitated by villi.

Page 15

Digestion Through the System

  • Large intestine absorbs water and salts, forms faeces for egestion.

Page 16

Understanding Enzymes

  • Enzymes as biological catalysts that facilitate digestion of macromolecules.

Types of Enzymes

  • Carbohydrase: Breaks down carbohydrates.

  • Lipase: Breaks down fats.

  • Protease: Breaks down proteins.

Page 17

Enzyme Functionality

  • Enzymes are specific to substrates; incorrect conditions can denature them.

Page 18

Other Uses of Enzymes

  • Applications in laundry, food processing, brewing, and baking.

Page 19

Role of Bacteria in Digestion

  • Bacteria are essential for digesting certain nutrients and preventing harmful bacterial growth.

Types of Bacteria

  • Good vs. Bad Bacteria: Only specific types contribute positively to digestion.

Page 20

Key Concepts About Bacteria

  • Bacterial structure and function, emphasizing their role in digestion and health.