Understanding the Importance of Food and Nutrition

Study Notes

Why Do We Need Food?

Humans consume a balanced diet that contains a variety of different types of food, including carbohydrates, proteins, fats, vitamins, and minerals.
The main nutrients needed by the body are:
- Carbohydrates for energy
- Proteins for growth and repair
- Fats for energy storage
- Vitamins and minerals for overall health

Food Types and Composition

Carbohydrates:
- Made of long chains of identical, small sugar molecules
- The body breaks down long chains into smaller sugar molecules for energy
Proteins:
- Made of long chains of small, non-identical molecules (amino acids)
- There are over 20 kinds of amino acids
- Used for growth and repair
Fats:
- Made up of fat molecules containing fatty acids and glycerol
- Used for energy storage and to make cell membranes

Releasing Energy from Food

Problems with releasing energy from food:
- Physical means cannot break down long chain molecules
- Large food molecules are insoluble and cannot be dissolved in the blood
The digestive system must cope with these problems to release energy

Digestive System

An organ system made up of a group of organs working together
Each organ has a specific function, and together they achieve digestion
The digestive system is responsible for breaking down food into smaller, soluble molecules

What Happens to Food in the Body?

Food is digested, which means it is broken down into smaller molecules
Digestion occurs in two ways: physical/mechanical and chemical
Physical digestion breaks down the physical shape of food, while chemical digestion breaks down chemical bonds

Chemical and Physical Digestion

The body uses both physical and chemical digestion to break down food
Physical digestion changes the shape of food to fit through the digestive system
Chemical digestion breaks down chemical bonds to release useful chemicals and dissolve them in the blood

Digestive Tract

The digestive system is a long tube (approximately 9m when stretched out) with an opening at each end
The digestive tract includes the mouth, anus, gastrointestinal tract, liver, pancreas, and gallbladder
The tube is extremely folded to fit inside the body and passes through various organs on its route from the mouth to the anus

Description

Discover the role of a balanced diet in maintaining human health. Learn about the main nutrients required by the body, including carbohydrates, proteins, fats, vitamins, and minerals. Understand the concept of the food pyramid and how it guides our nutritional needs.