Question

In animals, extra protein is:

1.absorbed by the cells
2. released through respiration
3. excreted as waste material
4. all of the above

Answer 1

Extra protein in animals is excreted as waste material because excess nitrogen is toxic. In mammals, the liver synthesizes urea as the principal waste product.

Step-by-step explanation:

Proteins are hydrolyzed by enzymes in cells, and most of the amino acids are recycled into the synthesis of new proteins. However, if there are excess amino acids or if the body is in a state of starvation, some amino acids will be converted into glucose or triglycerides for energy or energy reserves.

The nitrogen derived from protein breakdown must be excreted as waste material since excess nitrogen is toxic. In mammals, the liver synthesizes urea from nitrogen, which is the principal waste product excreted from the body.