We already showed you some information about amino acids. Proteins are made of amino acids. Even though a protein can be very complex, it is basically a long chain of amino acids, all twisted around like a knot.

PRIMARY STRUCTURE

As proteins are being built, they begin as a straight chain of amino acids. This chain structure is called the primary structure. Sometimes chains can bond to each other with two sulfur (S) atoms. Those bonds would be called a disulfide bridge.

SECONDARY STRUCTURE

After the primary structure comes the secondary structure. The original chain begins to twist. It's as if you take a piece of string and twist one end. It slowly begins to curl up. In the amino acid chain, each of the amino acids interacts with the others and it twists like a corkscrew or a flat folded sheet.

TERTIARY MAKES STEP THREE

Let's move on to the tertiary structure of proteins. By now you're probably getting the idea that proteins do a lot of folding and twisting. The third step in the creation of a protein is the tertiary structure when the amino acid chains begin to fold even more and bond using more bridges (the disulfide bridges).

QUATERNARY IS FOURTH AND FINAL

We can finally cover the quaternary structure of proteins. Quaternary means four. This is the fourth phase in the creation of a protein. In the quaternary structure, several amino acid chains from the tertiary structure fold together in a blob. They wind in and out of each other. You heard it right. Blob is the scientific term.

RELATED LINKS

- Biology4Kids: Scientific Method
- Biology4Kids: Cell Structure
- Geography4Kids: Carbon Cycle
- Geography4Kids: Biosphere

-	Overview
-	Metabolism
-	Cycles
-	Carbohydrates
-	Lipids
-	Nucleic Acids
-	DNA
-	Amino Acid Structure
-	20 Amino Acids
>	Proteins
-	Enzymes
-	Enz. Regulation
	MORE CHEMISTRY TOPICS

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