Ammonium ions are a toxic waste product of the metabolism in animals... In mammals... it is converted in the urea cycle to urea, because it is less toxic and can be stored more efficiently.
Urea or carbamide is an organic compound with the chemical formula (NH2)2CO. The molecule has two amine (-NH2) groups joined by a carbonyl (C=O) functional group.
This mechanism, which is controlled by the antidiuretic hormone, allows the body to create hyperosmotic urine, that has a higher concentration of dissolved substances than the blood plasma. This mechanism is important to prevent the loss of water, to maintain blood pressure, and to maintain a suitable concentration of sodium ions in the blood plasmas.
The equivalent nitrogen content (in gram) of urea (in mmol) can be estimated by the conversion factor 0.028 g/mmol. Furthermore, 1 gram of nitrogen is roughly equivalent to 6 gram of protein, and 1 gram of protein is roughly equivalent to 4 gram of muscle tissue. Subsequently, in situations such as muscle wasting, 1 mmol of excessive urea in the urine (as measured by urine volume in litres multiplied by urea concentration in mmol/l) roughly corresponds to a muscle loss of 0.67 gram.
FYI: UREA IS ABOUT 50% OF NITROGENOUS WASTE.
Uric acid is a heterocyclic compound of carbon, nitrogen, oxygen, and hydrogen with the formula C5H4N4O3. It forms ions and salts known as urates and acid urates such as ammonium acid urate. Uric acid is created when the body breaks down purine nucleotides. High concentrations of uric acid in blood serum can lead to a type of arthritis known as gout. The chemical is associated with other medical conditions like ammonium acid urate kidney stones.
Creatine is naturally produced in the human body from amino acids primarily in the kidney and liver. It is transported in the blood for use by muscles. Approximately 95% of the human body's total creatine is located in skeletal muscle.
Creatine is not an essential nutrient, as it is manufactured in the human body from L-arginine, glycine, and L-methionine.
In humans and animals, approximately half of stored creatine originates from food (mainly from meat). Since vegetables do not contain creatine, vegetarians show lower levels of muscle creatine, but show the same levels after using supplements.