Nutrients and the Digestive System: Functions, Sources and Key Concepts
Nutrients
Nutrients are small organic and inorganic molecules that make up food. They provide energy and are the building material our cells need to maintain their functions.
Carbohydrates
Carbohydrates provide immediate energy to the cell and are involved in the production of metabolic reactions. They form part of plasma membranes.
Sources: sugar, pasta, bread, rice.
Lipids
Lipids provide energy to cells and are stored as reserve energy, making them a complementary source to carbohydrates. They form part of the plasma membrane (phospholipids) and regulate reproductive functions (sexual hormones).
Sources: animal fats, vegetable oils, margarine, peanuts, nuts.
Proteins
Proteins form part of cells. They catalyze chemical reactions (enzymes) and are involved...