Get premium membership and access questions with answers, video lessons as well as revision papers.

Explain the basic Protein and Amino acid Metabolism in Mammals.

      

Explain the basic Protein and Amino acid Metabolism in Mammals.

  

Answers


sharon
Many of amino acids absorbed into portal blood are removed as the blood passes the liver, so they never reach the general circulation. For instance in the dog only about 23% of the amino acids reaching the liver as a result of absorption will pass into the general circulation. The liver therefore helps in keeping blood amino acid concentrations low. Some of the amino acids taken up by the liver (about 20%) are used for protein synthesis.
Most of the amino acids entering the liver undergo deamination i.e. the amino groups are removed and the molecules converted to their keto-analogues. Keto-analogues are carbohydrates having similar structures to respective amino acids. For example, glutamate and aspartate are two amino acids similar to two Krebs cycle intermediates a-ketogluterate and oxaloacetate respectively. Once amino acids have been deaminated their keto-analogues enter the pathways of carbohydrate metabolism from which they may be completely metabolized for energy, converted to glucose or glycogen, or shunted to fatty acid synthesis. Fatty acid synthesis mainly takes place in adipose tissue while glycogen formation maily takes place in liver and skeletal muscle.
Urea formation is also a key function of the liver in relation to protein metabolism. Large amounts of ammonia are usually formed during the deamination process and additional amounts are continually formed in the gut by bacteria and then absorbed into the blood. By forming urea, the liver helps in removing ammonia from body fluids. The urea formed is taken to the kidneys and excreted through urine.
sharon kalunda answered the question on February 25, 2019 at 14:14


Next: Explain the basic Lipid Metabolism in Mammals.
Previous: Explain the basic Carbohydrate Metabolism in Mammals.

View More Animal Physiology Questions and Answers | Return to Questions Index


Learn High School English on YouTube

Related Questions