Question

2. Proteins degradation provides free amino acids, which may be further degraded by deamination and transamination in order to synthesis new compounds, produce energy, or eliminate waste. Provide a brief description for each of the possible fates of free amino acids with specific reference to biochemical reactions and state how the products of these reactions may are utilized.

3. Consider the amount the ATP yield from two different 6-carbon biomolecules: fructose and caproic acid. With specific reference to the catabolic pathways and processes, explain why the ATP yield from caproic acid is greater then the ATP yield from fructose.

Answer 1

Protein degradation is one of the many reasons for the amino acid pool.The possible fates of free amino acids are:

• Structural protein biosynthesis, like the tissue proteins
• Some non protein nitrogens are also synthesized from the amino acid pools, like urea, ammonia, creatinin etc. that take part in the urea cycle
• Different functional proteins including the globin family proteins like haemoglobin, myoglobin etc are synthesized by the amino acids
• Small biologically important peptides are also synthesized by the amino acids, like glutathione, endorphins etc.
• Synthesis of enzymes, transporters, neurotransmitters,intermediates of the TCA cycle are all produced by the help of the amino acids
• They aid in the supply of glucose and glycogen by various metabolic pathways
• The deamination and transamination processes help these amino acids to produce more new kinds of amino acids and nitrogenous products.

In case of caproic acid :

During beta oxidation, caproic acid produces almost 36-39 ATP which is greater than the fructose

In case of fructose:

Roughly, fructse produces almost 30 molecules of ATP after complete oxidation.

This vast difference is due to the presence of acetyl coA during the inetrmediate step. This acetyl coA then enters the citric acud cycle and and thus helps in production of more ATP during the process