It is a less invasive surgery, so your recovery time is shorter and easier than with mastectomy. Lumpectomy has a few potential disadvantages: You are likely to have 5 to 7 weeks of radiation therapy, 5 days per week, after lumpectomy surgery to make sure the cancer is gone.
DNA: Double Helix. The secondary structure of DNA is actually very similar to the secondary structure of proteins. The protein single alpha helix structure held together by hydrogen bonds was discovered with the aid of X-ray diffraction studies. The X-ray diffraction patterns for DNA show somewhat similar patterns.
Protein Structure. Proteins are polymers of amino acids. The amino acids of a protein are linked by peptide bonds. Alpha helices and beta pleated sheets are characteristic of a protein's secondary structure. Electronegative oxygen and nitrogen atoms leave hydrogen atoms with partial positive charges. Peptide bonds link together the amino acids of a protein's primary structure.