Chapter 6 Form 4 Nutrition Part 1

1. 6.1 Types of Nutrition
Types of Nutrition
Autotrophic
Organism that synthesised complex organic
molecules from inorganic molecules
Heterotrophic
Obtain energy and organic compunds from
other organism
Photosynthesis Chemosynthesis
• Photoautotrophs
• Absorb light
energy and
produce organic
molecules from
C0₂ and H₂0
• Chemoautotrophs
• Organism
synthesises
organic molecules
using energy
obtaines from
oxidation of
inorganic
substances
• Nitrosomonas –
ammnium 
nitrate
• Nitrobacter:
nitrate  nitrate
Holozoic
Saprophytic Parasitic
• Ingestion: taking in large and complex
molecules
• Digestion: breakdown of large particles
into smaller particles and chemically
digested by enzymes
• Absorption: movement of dissolved
substance across plasma membrane into
cells
• Assimilation: utilisation of absorbed food
in the body
• Egestion: Elimination of waste from the
body
• Feed on dead
decaying matter
• Mucor & Rhizopus
• Obtain nutrients from
other living organism
• Tapeworm, Fleas, Lice

2. 6.2 Balanced diet
Balanced diet consists of 7 classes of food
Carbohydrates Lipids Proteins
Mineral salts H₂0 Dietary fibres
Provides
• Energy for cellular metabolism
• Growth and development
• Maintain good health
Factors affecting daily energy requirements of different individuals
Factors Details
Age • Children require more energy for growth –
high metabolic rate
Sex • Male adult has higher energy requirement
than female
Body size &
weight
• Bigger body size and weight require more
energy for basal metabolism
Occupation • Heavy jobs require more energy
Pregnancy &
lactation
• Breast feeding mothers require more energy
Climate • People from cold climate country require
more energy to maintain optimum body
temperature

3. 6.2 Balanced diet – Determination of Energy Value in Food Samples

4. 6.2 Balanced diet – Determination of Energy Value in Food Samples

5. 6.2 Balanced diet – Vitamins
Fat Soluble Vitamins

6. 6.2 Balanced diet – Vitamins
Water Soluble Vitamins

7. 6.2 Balanced diet – Vitamins
Minerals

8. 70% of total body weight
Amount needed depends on
environmental condition
Water loss from urine,
sweat, faeces and
evaporation during
breathing
7 Functions:
• Component of protoplasm
• Solvent
• Medium for biochemical reaction
• Component of blood plasma: transport
medium for nutrients, respiratory gases,
waste substances
• Regulates body temperature
• Production of digestive juices, mucus,
tears and synovial fluid
• Maintain osmotic pressure