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.
Many proteins are actually assemblies of multiple polypeptide chains. The quaternary structure refers to the number and arrangement of the protein subunits with respect to one another.Examples of proteins with quaternary structure include hemoglobin, DNA polymerase, and ion channels.he quaternary structure refers to the number and arrangement of the protein subunits with respect to one another. Examples of proteins with quaternary structure include hemoglobin, DNA polymerase, and ion channels.