Proteins consumed by the cat are broken down and
converted into urea nitrogen, which is then excreted by the kidneys, along with other waste products.
I only picked up this: ``... unlike essentials... precursers shunted into...
oxidized into urea?
Under standard conditions, 90 % of excess protein is
turned into urea (a non-toxic waste product) and excreted in the urine.
ATP (energy molecules) are used to convert amino acids to glucose, and even more are then required to convert the harmful protein byproduct ammonia
into urea which is flushed away by the kidneys.
It takes place in the liver, uses a dizzying slew of enzymes, and creates nitrogen waste that has to be
converted into urea and disposed of through the kidneys.
Arginine: Aids in the conversion of the toxic waste product
ammonia into urea to be excreted from the body via urine.
In this process nitrogen groups are removed from the amino acids which are converted
into urea and removed from the body by the kidneys.
Unfortunately, your liver will start struggling and failing to convert the ammonia
into urea (not enough ATP) so the ammonia will reenter your blood stream.
This means the liver can not perform its primary function, which is to convert ammonia (a by - product of protein breakdown)
into urea, which is less toxic.
By the time blood percolates to the center of the lobules, hepatocytes have detoxified unwanted products that were absorbed through the intestine, synthesized a number of blood proteins, produced fatty acids from the carbohydrates in the pet's diet, converted waste ammonia
into urea, and synthesized cholesterol and bile salts and stored sugar (glucose) from the blood in the form of glycogen.