Metabolism of Nitrogenous Compounds

Metabolism of Nitrogenous Compounds

• This presentation covers the metabolism of various nitrogen-containing compounds.
• Learning objectives include describing protein digestion, reactions for separating amino groups from amino acids, the fate of carbon skeletons, glucogenic and ketogenic amino acids, biogenic amines, and examples of nitrogenous compounds.
• Nitrogenous compounds addressed include amino acids (proteins), biogenic amines, porphyrins, and nucleobases.
• The metabolism of amino acids involves protein degradation and synthesis. Amino acids can be used for energy production or to create other compounds.
• Transamination is a key reaction that transfers an amino group from one molecule to another.
• Oxidative deamination removes the amino group from an amino acid, producing ammonia (NH3).
• Ammonia is toxic, so the body converts it to urea for detoxification and excretion.
• The urea cycle is the pathway used to convert ammonia into urea.
• The urea cycle has multiple steps and involves several enzymes.
• Amino acid degradation involves separating the amino group from the molecule, and the metabolism of the remaining carbon skeleton.
• Different amino acids are divided into glucogenic and ketogenic types, based on if they can be used to create glucose or ketone bodies.
• The presentation also covers protein digestion, discussing the enzymes involved and the process of breaking down proteins into smaller units.
• The presentation explains how protein digestion works, including enzymes that help to break down peptide bonds.

Amino Acid Metabolism

• Proteins are not stored in the body for long-term energy.
• Amino acids are broken down (degraded).
• Amino acids can be converted to glucose or fatty acids
• When energy sources like carbohydrates are low, the body uses amino acids.
• The amino group is removed from amino acids through transamination and oxidative deamination to produce ammonia.
• The ammonia is then converted into urea in the urea cycle.
• The remaining carbon skeletons from amino acids can enter the citric acid cycle to generate energy.

Biogenic Amines

• Biogenic amines are important molecules in the body, including neurotransmitters.
• Biogenic amines are derived from amino acids and have diverse functions, including roles in brain function, as neurotransmitters, and involvement in the body's response to stimuli.
• The molecules include dopamine, norepinephrine, epinephrine, and serotonin, among others, with their specific pathways for biosynthesis and degradation are discussed.
• The breakdown of biogenic amines is also discussed.

Porphyrins

• Porphyrins are a class of compounds containing rings and are involved in crucial cellular functions, including those related to transporting and storing oxygen.
• Porphyrin degradation disorders exist and may lead to jaundice and can be toxic when toxic intermediates are produced.
• These molecules are key components, particularly in heme synthesis and have some specific health-related issues.

Nucleotide Metabolism

• Nucleotides are composed of a nitrogenous base, a pentose sugar, and a phosphate group. Different types of bases can exist within a nucleotide.
• The pathways for the breakdown of nucleotides are also discussed, which include their component parts, and different structures of purines and pyrimidines.
• Nucleotide metabolism involves the creation of both RNA and DNA.
• The presentation covers the biosynthesis of purines and pyrimidines, the component parts, their roles in creating genetic materials, and their metabolic pathways.