The backbone of protein structure makes _____________ between the amide hydrogen and carbonyl oxygen of two different amino acids.

The backbone of protein structure refers to the repeating sequence of the amino acid chain, specifically involving the amide (or peptide) bonds that link the amino acids together. In this context, hydrogen bonds play a crucial role in stabilizing the three-dimensional structure of proteins, particularly in the formation of secondary structures such as alpha helices and beta sheets.

Hydrogen bonds occur when a hydrogen atom, covalently bonded to a highly electronegative atom (such as nitrogen in the amide group), interacts with another electronegative atom (such as oxygen in the carbonyl group). This type of interaction is vital in protein folding and stability. The presence of the backbone amide and carbonyl groups in the protein chain allows for this interaction to occur between different parts of the protein or between separate protein molecules.

In summary, the hydrogen bonds formed between the amide hydrogen of one amino acid and the carbonyl oxygen of another are essential for maintaining the structural integrity of proteins as they contribute to the overall architecture and functionality of the molecules.