Protein and Nucleic Acid Digestion

Protein Digestion

Enzymes Involved

• Pancreatic Enzymes: The pancreas produces enzymes which are crucial for protein digestion.
  • Trypsinogen
  • Chymotrypsinogen
  • Proelastase
  • Procarboxypeptidase
  • These enzymes are released in inactive forms (pro- or -gen) to prevent self-digestion of the pancreas.

Activation Process

• Enterokinase: An enzyme in the small intestine that activates trypsinogen into trypsin.
  • Trypsin then activates other pancreatic enzymes:
    • Chymotrypsinogen → Chymotrypsin
    • Proelastase → Elastase
    • Procarboxypeptidase → Carboxypeptidase

Function

• Trypsin, Chymotrypsin, Elastase: Break down proteins at specific amino acid sites.
• Carboxypeptidase and Aminopeptidase: Cleave amino acids from the ends of the peptide chain:
  • Carboxypeptidase: Removes amino acids from the carboxyl end one at a time.
  • Aminopeptidase: Removes amino acids from the amino end one at a time.
  • Dipeptidase: Breaks the bond between the last two amino acids.

Result

• The digestion process produces amino acids and dipeptides which are then transported to the liver.

Nucleic Acid Digestion

Nucleic Acids

• Nucleic Acids: DNA and RNA, composed of nucleotides.
• Nucleotide Structure: Composed of a five-carbon sugar, a phosphate group, and a nitrogen-containing base (A, G, C, T for DNA; A, D, U, C for RNA).

Enzymes Involved

• Pancreatic Enzymes: Responsible for breaking down nucleic acids.
  • DNase: Breaks down DNA.
  • RNase: Breaks down RNA.

Process

• Nucleotides are broken down further, but DNase and RNase play the initial role in breaking down DNA and RNA into nucleotides.
• Hydrolysis: Process of breaking bonds by adding water.
• Dehydration Synthesis: Process of forming bonds by removing water.

Additional Notes

• DNA is double-stranded; RNA is single-stranded.
• These processes are crucial for breaking down dietary nucleic acids into usable components.