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.
Blockage of the bile ducts may cause symptoms such as abdominal pain, nausea and vomiting. If the bile duct remains blocked bile is unable to drain properly, jaundice (yellow discoloration of the eyes and skin) can develop and an infection known as cholangitis may also occur.ccasionally the gallstones can also block the flow of digestive enzymes from the pancreas because both the bile ducts and pancreas ducts drain through the same small opening (called the Ampulla of Vater) which is held tight by a small circular muscle (called the Sphincter of Oddi).