uric acid

(noun)

a bicyclic heterocyclic phenolic compound, formed in the body by the metabolism of protein and excreted in the urine

Related Terms

Examples of uric acid in the following topics:

  • Nitrogenous Waste in Birds and Reptiles: Uric Acid

    • In contrast, mammals (including humans) produce urea from ammonia; however, they also form some uric acid during the breakdown of nucleic acids.
    • Uric acid is a compound similar to purines found in nucleic acids.
    • Uric acid is also less toxic than ammonia or urea.
    • Uric acid is released in hypoxic conditions.
    • These include (a) ammonia, (b) urea, and (c) uric acid.

  • Some Polycyclic Heterocycles

    • Xanthine and uric acid are products of the metabolic oxidation of purines.
    • Uric acid is normally excreted in the urine; an excess serum accumulation of uric acid may lead to an arthritic condition known as gout.

  • Malpighian Tubules of Insects

    • Metabolic wastes, such as urea and amino acids, freely diffuse into the tubules, while ions are transported through active pump mechanisms.
    • The secretion of ions alters the osmotic pressure, which draws water, electrolytes, and nitrogenous waste (uric acid) into the tubules.
    • Water and electrolytes are reabsorbed when these organisms are faced with low-water environments and uric acid is precipitated and excreted as a thick paste or powder.

  • Bone and Joint Disorders

    • Gout is a form of arthritis that results from the deposit of uric acid crystals within a body joint.
    • Gout occurs when the body makes too much uric acid or the kidneys do not properly excrete it.

  • Homeostatic Responses to Shock

    • The increase in acidity will initiate the Cushing reflex, generating the classic symptoms of shock, where the individual will begin to hyperventilate in order to rid the body of carbon dioxide to raise the pH of the blood (lower the acidity) and resulting in the baroreceptors in the arteries to detect the hypotension and initiating the release of epinephrine and norepinephrine in order to increase the heart rate and blood pressure.
    • Adenosine easily perfuses out of cellular membranes into extracellular fluid, furthering capillary vasodilation, and then is transformed into uric acid.
    • Adenosine easily perfuses out of cellular membranes into extracellular fluid, furthering capillary vasodilation, and then is transformed into uric acid.

  • Renal Calculi

    • Fruit juices contain antioxidants and citric acid, which help dissolve kidney stones.
    • Urinary stones are typically classified by their location in the kidney (nephrolithiasis), ureter (ureterolithiasis), or bladder (cystolithiasis), or by their chemical composition (calcium-containing, struvite, uric acid, or other compounds).

  • Overview of the Urinary System

    • Removal of metabolic waste products from the body (mainly urea and uric acid)
    • Regulation of acid-base homeostasis and blood pH, a function shared with the respiratory system.

  • Characteristics of Birds

    • Uric acid is not expelled as a liquid, but is concentrated into urate salts, which are expelled along with fecal matter.

  • Placenta

    • Waste products excreted from the fetus - urea, uric acid and creatinine - are transferred to the maternal blood by diffusion across the placenta.

  • Vertebrate Digestive Systems

    • In order to speed up the actions of enzymes in the stomach, the stomach has an extremely acidic environment, with a pH between 1.5 and 2.5.
    • Instead, uric acid from the kidneys is secreted into the large intestine and combined with waste from the digestive process.