In this lesson, you’ll learn about the primary structure, function, and sources of protein molecules while exploring some real-world examples and illustrations.
Protein: The Inside Story
The human body uses proteins for many things, including repairing and building tissues, acting as enzymes, aiding the immune system, and serving as hormones.
Each of these important functions requires a slightly different form of protein. In spite of their differences in structure, all proteins contain the same basic sub-components.Proteins are one of the four different types of macromolecules, in addition to carbohydrates, lipids, or fats, and nucleic acids, such as DNA and RNA. Macromolecules are large molecules that perform specialized functions inside living organisms. The structural arrangement of a protein molecule will differ in accordance with its function.
Amino Acids ; Proteins
Proteins are long chains of amino acids.
Amino acids are the building blocks of protein. In other words, amino acids are like the links in a chain. The chain itself represents the protein molecule. Protein chains are then twisted and folded together in specific ways to create certain molecules.
This example shows our primary protein chain as it’s twisted into a helical shape, folded into a sheet, and then twisted all over again into an intricate globular shape. In this case, the final product is a protein molecule known as hemoglobin, which can be found in your blood.
Sources of Protein
Earlier, we mentioned that protein plays a role in tissue repair, and that’s why it’s so important to have protein in your diet. But what are the best sources of protein? And, are there different types of protein? Let’s explore these questions. Afterwards, you might take a look in your refrigerator and decide whether your diet is protein rich or protein poor.
Protein can be found in all living things. The type and amount of protein within foods can vary, but inevitably, it’s there in some form. Meats, cheeses, and nuts tend to have a higher protein content than many plant-based sources.
To determine the protein content of a food, we’ll need to read its nutrition label.
According to the this nutrition label, this food source has three grams of protein. In comparison to most foods, three grams of protein doesn’t amount to a whole lot.
And what this label doesn’t tell us is whether the protein is complete or incomplete. Complete proteins generally come from animal sources and contain all the amino acids required for protein-building within your body. Plant sources tend to provide fewer of these required amino acids; as a result, they’re considered incomplete proteins.
Protein is used for tissue repair and as enzymes, antibodies, and messenger hormones. Proteins are made from long chains of amino acids.
Amino acids are the subunits, or links, that compose a protein chain. All protein molecules are built from these subunits. However, the specific shape of a protein molecule is determined by its function. Protein is one of the four macromolecules. Macromolecules are large molecules in your body that perform specific functions.
Proteins Key Terms
- Protein: long chains of amino acids
- Amino Acids: the building blocks of protein
- Macromolecules large molecules that have specialized functions
- Complete proteins : proteins from animal sources and contain the amino acids necessary for protein-building
- Incomplete proteins : plant-sourced proteins
Apply your acquired knowledge of protein as you test your ability to achieve these objectives:
- Discuss the various uses for proteins in the human body
- Emphasize the need for amino acids
- List a few sources of protein