RNA is a very similar molecule to DNA, and only has two chemical differences. The overall structure of RNA and DNA are immensely similarâone strand of DNA and one of RNA can bind to form a double helical structure.NA also uses a different set of bases than DNAâ adenine, guanine, cytosine and uracil, instead of adenine, guanine, cytosine and thymine. Chemically, uracil is similar to thymine, differing only by a methyl group, and its production requires less energy.
Symptoms of a blocked bile duct include: 1  Yellowing of the skin (jaundice) or eyes (icterus), from the buildup of a waste product called bilirubin. 2  Itching (not limited to one area; may be worse at night or in warm weather) 3  Light brown urine. 4  Fatigue. Weight loss.  Fever or night sweats.
Bile duct cancer is not common, and these symptoms and signs are more likely to be caused by something other than bile duct cancer. For example, people with gallstones may have many of these same symptoms. There are many far more common causes of abdominal pain than bile duct cancer. And hepatitis (an inflamed liver most often caused by infection with a virus) is a much more common cause of jaundice.