Proteins are large molecules made up of smaller units called amino acids. They are essential building blocks of life, found in every cell of the human body. But what exactly do proteins contain?
Chemical Composition
At a fundamental level, proteins contain several key elements:
- Carbon (C): Forms the backbone of amino acids.
- Hydrogen (H): A crucial component of amino acid structure.
- Oxygen (O): Present in various parts of the amino acid structure.
- Nitrogen (N): A unique element found in the amino group of amino acids, distinguishing proteins from carbohydrates and fats.
- Sulfur (S): Present in some amino acids, like cysteine and methionine, contributing to protein structure and function.
Types of Amino Acids and Protein Sources
Proteins are composed of chains of amino acids, linked together in specific sequences determined by our genes. There are 20 different amino acids, some of which our bodies can produce (non-essential), and others we must obtain through our diet (essential).
Examples of protein sources include:
- Lean meats: Beef, lamb, veal, pork, kangaroo
- Poultry: Chicken, turkey, duck, emu, goose, bush birds
- Fish and seafood: Fish, prawns, crab, etc.
- Dairy products: Milk, cheese, yogurt (Greek yogurt is particularly high in protein)
- Eggs: A complete protein source, containing all essential amino acids.
- Legumes: Beans, lentils, peas (often incomplete proteins, meaning they lack some essential amino acids)
- Nuts and seeds: Provide protein but often lack some essential amino acids.
- Soy products: Tofu, tempeh, soy milk are good plant-based protein sources.
- Turkey Breast: High in protein, low in fat and calories, and contains several vitamins and minerals (selenium, zinc).
Some plant-based proteins may not contain all essential amino acids, unlike animal-based proteins which are usually complete proteins. However, combining various plant-based protein sources throughout the day can ensure you receive all the essential amino acids.
Note: Processed protein powders can contain added sugars, calories, or potentially harmful chemicals; it's crucial to check labels.