The Architecture of Matter and Its Origins

The drawings on the hottom show architectural elements that appear in proteins. The drawing on the left-hand side shows that protein chains can assume a helical shape, called an a-helix (as shown in purple), or a sheet shape, called a p-sheet (as shown in green). The drawing on the right shows two protein parts that maintain NH 0 contacts, which is the architecture that appears in silk. 

What are these contacts which bring about intermolecular forces that hold molecules together This is our next subtopic. 

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