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.
Two complementary regions of nucleic acid molecules will bind and form a double helical structure held together by base pairs. In molecular biology, the term double helix refers to the structure formed by double-stranded molecules of nucleic acids such as DNA.he DNA double helix polymer of nucleic acids, held together by nucleotides which base pair together. In B-DNA, the most common double helical structure, the double helix is right-handed with about 10â10.5 base pairs per turn. This translates into about 20-21 nucleotides per turn.