Nutrients and Human Nutrition

Polysaccharides

• Include starch, cellulose, and glycogen (animal starch)

Proteins

• Molecules composed of carbon, hydrogen, oxygen, nitrogen, and sometimes sulfur and phosphorus atoms
• Formed by joining hundreds or thousands of amino acid molecules together in long chains
• Proteins have 20 different common amino acids
• Can be denatured by heat or certain chemicals
• Some are globular in structure and are soluble in water (e.g. hemoglobin and albumin)
• Others are fibrous and are insoluble (e.g. collagen and keratin)

Lipids

• Fats and oils composed of carbon, hydrogen, and oxygen atoms
• Have fewer oxygen atoms than carbohydrate molecules
• Each lipid molecule is made up of four smaller molecules: three fatty acid molecules and one glycerol molecule
• Feel greasy, are insoluble in water, and leave a grease spot on paper

Tests for Carbohydrates, Proteins, and Lipids

• Carried out in a laboratory to identify carbohydrates, proteins, and lipids
• Tests are usually performed on a 2 cm3 solution of the test substance in a test tube

Sources and Functions of Carbohydrates, Proteins, and Lipids

• Supply the body with energy and the materials for growth and repair
• Organic compounds essential for healthy growth and development

Vitamins and Minerals

• Vitamins are organic compounds and minerals are inorganic substances
• Required in small amounts by the human body, but essential for healthy growth and development
• Vitamins: A, D, E, and K (fat-soluble), and Group B vitamins and vitamin C (water-soluble)
• Minerals: calcium, iron, phosphorus, iodine, sodium, potassium, and fluorine

Vitamin and Mineral Deficiency Diseases

• A shortage or lack of essential vitamins or minerals in the diet can lead to health problems and certain deficiency diseases

Nutrition and the Human Diet

• Nutrition is the process by which living organisms obtain or make food
• The human diet must contain carbohydrates, proteins, lipids, vitamins, minerals, water, and dietary fiber
• Carbohydrates, proteins, and lipids are macronutrients, required in relatively large quantities
• Vitamins and minerals are micronutrients, required in relatively small quantities

Explore the essential nutrients needed by humans, such as carbohydrates, proteins, lipids, vitamins, and minerals. Learn about the process of nutrition and the components of a healthy human diet.