The voltage delivering 1 watt depends on how many amps are present. We use watts to measure power (P), and amps (I) times volts (E) equals watts.
The liver and the production of urea Urea is a nitrogen-containing substance which is produced in the liver, in order to deal with excess amino-acids in the body, which is a natural consequence of the fact that we almost always eat more protein than our body needs to assimilate. The process is called deamination.
Urea waste. Urea is excreted by the kidneys, and is less toxic than ammonia and can be transported in the blood from the liver where it is formed from ammonia. This molecule is very small, diffuses easily across cell membranes and requires no specialized transport system.