Urea cycle is a very important metabolic pathway to degrade the carbon skeleton left from amino acid catabolism. 

Classified as a group of dietary fiber, lignin cannot be digested by animal enzymes, but can be digested by microbial enzymes.

Which one of the following formulas represents a tetrose? A)  C3H6O3-C3H6O3-C3H6O3-C3H6O3-C3H6O3 B)  C4H8O4 C)  C5H10O5 D)  C6H12O6-C6H12O6-C6H12O6-C6H12O6 E)  C7H14O7  

Phenylalanine is one of the aromatic amino acids.            

The electron transport chain pathway takes place in in mitochondria and, therefore, it requires oxygen (O2) as the final electron receiver.

The Urea Cycle for ammonia detoxification in the body involves the following amino acids:(A) L-Arginine(B) L-Ornithine(C) L-Citulline(D) All of the above(E) None of the above

Besides ATP,  CO2, and NADH, another important final product of the Krebs cycle is _________________________.

What is the physiological or biochemical reasons for the ketosis to occur? Identify at least one situation when this problem occurs in livestock.

Which one of the following amino acids is a sulfur containing amino acid?

In birds, food passes through the proventriculus before entering the gizzard.