Metabolism

• All chemical reactions takes place in the living cell

Waste products

An unusable or unwanted substance or material produced during or as a result of a process such as metabolism or manufacturing

• The waste products formed from the metabolism of carbohydrate
  • Water = aerobic
  • CO₂ =aerobic
  • Lactic acid = anaerobic
• The waster products formed for the metabolism of fats
  • H₂O=aerobic
  • CO₂ =aerobic
• The waste products formed from the metabolism of protein
  • NH₃
  • Urea
• The waste products formed from the metabolism of nucleic acid
  • NH₃
• The waste products formed from the metabolism of creatine
  • Creatinine
• The main nitrogenous waste of animals
  • NH₃
  • Urea
  • Uric acid
  • Creatinine
• Type of excretory waste product produce by the organism depends on following factors,
  1. Availability or unavailability of enzyme.
  2. Amount of utilizable water present in the environment
  3. Degree of control of loss of water

Bile pigments

Hemoglobin →Haem  →  bilirubin, biliverdin (bile pigments)

• urobilinogen removed with urine
• In stomatch,

Urobilinogen →   stercobilin

• Stercobilin removes with feaces

Excretion

• is the removal of waste products of metabolism from the body

Need of excretion

• accumulation of waste products in body cause toxicity to the cell
• accumulation of water products cause PH changes
• helps to maintain constant homeostasis

Excretory structures