RNA. A type of nucleic acid consisting of nucleotide monomers with a ribose sugar and the nitrogenous bases adenine (A), cytosine (C), guanine (G), and uracil (U); usually single-stranded; functions in protein synthesis and as the genome of some viruses.
Underactive thyroid Photo Credit George Doyle/Stockbyte/Getty Images. It's hard to lose weight when your metabolism slows down, but there are things you can do. The thyroid, a butterfly-shaped gland in your throat, produces hormones that regulate many bodily functions, including metabolism.ollow a low-calorie diet. Anyone who wants to lose weight must burn more calories than are consumed. Unfortunately, for someone with an underactive thyroid, it can be difficult because the metabolism slows, meaning the body naturally burns fewer calories.
An underactive thyroid (hypothyroidism) is usually treated by taking daily hormone replacement tablets called levothyroxine. Levothyroxine replaces the thyroxine hormone, which your thyroid doesn't make enough of. You'll initially have regular blood tests until the correct dose of levothyroxine is reached.n underactive thyroid is a lifelong condition, so you'll usually need to take levothyroxine for the rest of your life. If you're prescribed levothyroxine because you have an underactive thyroid, you're entitled to a medical exemption certificate.