Question

What is deamination?

Answer 1

Hint: : It is a very important step in the formation of a more easily metabolizable form of amino acids. When excessive protein is present in the body then the deamination reaction occurs.

Complete answer:
Deamination is the process by which an amino group will be removed from the molecule. Enzymes that are involved in the catalysis of this reaction are called deaminases. In humans, the deamination will occur in the liver and kidney. The conditions during which we intake lots of protein, deamination will take place in which the amino acids will be broken down to obtain energy. The amino group is removed from the amino acid and is converted to ammonia. The remaining amino acids are majorly made of carbon and hydrogen and they are recycled or oxidized to obtain energy. Ammonia is highly toxic to the human system, and the enzymes will convert it into urea or uric acid by adding carbon dioxide molecules in the urea cycle. This process also occurs in the liver. Urea and uric acid will diffuse into the blood and then will be excreted via urine.
Deamination of DNA Example
Cytosine: The spontaneous deamination in DNA is the hydrolysis cytosine into uracil, thereby releasing the ammonia during this process. Deamination can be induced externally, under lab conditions (i.e., in vitro condition) by using bisulfite. Bisulfite deaminates cytosine, but not 5-methylcytosine. This property is used to differentiate between the methylated DNA to distinguish non-methylated cytosine and methylated cytosine.
Deamination will also occur in 5-methylcytosine, guanine, and adenine.

Note: Transamination is a chemical reaction which will transfer an amino group to a keto acid to synthesize new amino acids. This pathway is accountable for the deamination of amino acids. This is one of the chief pathways that is involved in the degradation which will convert essential amino acids to non-essential amino acids.