UrobilinogenUrobilinogen is a colorless by-product of bilirubin reduction. It is formed in the intestines by the bacterial enzyme bilirubin reductase. About half of the urobilinogen formed is reabsorbed and taken up via the portal vein to the liver, enters circulation and is excreted by the kidney. Increased amounts of bilirubin are formed in hemolysis, which generates increased urobilinogen in the gut.
StercobilinStercobilin is a tetrapyrrolicbile pigment and is one end-product of hemecatabolism. It is the chemical responsible for the brown color of human feces and was originally isolated from feces in 1932. Stercobilin (and related urobilin) can be used as a marker for biochemical identification of fecal pollution levels in rivers. MetabolismStercobilin results from breakdown of the heme moiety of hemoglobin found in erythrocytes (red blood cells).
BilirubinBilirubin (BR) (adopted from German, originally bili, for bile, plus ruber, Latin for red) is a red-orange compound that occurs as the reduction product of biliverdin, a breakdown product of heme. It is further broken down in the colon to urobilinogen, most of which becomes stercobilin, causing the brown color of feces. Some unconverted urobilinogen, metabolised to urobilin, provides the straw-yellow color in urine.
BiliverdinBiliverdin (from the Latin for green bile) is a green tetrapyrrolicbilepigment, and is a product of heme catabolism. heme Bbiliverdinbilirubin It is the pigment responsible for a greenish colour sometimes seen in bruises. MetabolismBiliverdin results from the breakdown of the hememoiety of hemoglobin in erythrocytes.
FecesFeces (also faecesorfæces or poop) are the solid or semi-solid remains of food that was not digested in the small intestine, and has been broken down by bacteria in the large intestine. Feces contain a relatively small amount of metabolic waste products such as bacterially altered bilirubin and dead epithelial cells from the lining of the gut. Feces are discharged through the anus or cloaca during defecation.
UrineUrine is the fluid excreted by the kidneys of vertebrates to clear the bloodstream of excess water and metabolic by-products including urea, uric acid, and creatinine. In mammals, urine travels from the kidneys via the ureters to the bladder for storage until urination. Placental mammals expel urine from the bladder through the urethra, whereas other vertebrates urinate through the cloaca. Urine plays an important role in the earth's nitrogen cycle.
TetrapyrroleTetrapyrroles are a class of chemical compounds that contain four pyrrole or pyrrole-like rings. The pyrrole units are linked by =CH− or −CH2− bridges, in either a linear or a cyclic fashion. Pyrroles are a five-atom ring with four carbon atoms and one nitrogen atom. Tetrapyrroles are common cofactors in biochemistry, and their biosynthesis and degradation feature prominently in the chemistry of life.
AlkaptonuriaAlkaptonuria is a rare inherited genetic disease which is caused by a mutation in the HGDgene for the enzymehomogentisate 1,2-dioxygenase (EC1.13.11.5); if a person inherits an abnormal copy from both parents (it is a recessive condition), the body accumulates an intermediate substance called homogentisic acid in the blood and tissues. Homogentisic acid and its oxidized formalkapton are excreted in the urine, giving it an unusually dark color.
PorphyriaPorphyria ( or ) is a group of disorders in which substances called porphyrins build up in the body, adversely affecting the skin or nervous system. The types that affect the nervous system are also known as acute porphyria, as symptoms are rapid in onset and short in duration. Symptoms of an attack include abdominal pain, chest pain, vomiting, confusion, constipation, fever, high blood pressure (hypertension), and high heart rate. The attacks usually last for days to weeks.
HemeHeme (American English), or haem (Commonwealth English, both pronounced // ), is a ring-shaped iron-containing molecule that serves as a ligand of various proteins, especially as a component ofhemoglobin, which carries oxygen in the bloodstream. It is composed of four pyrrole rings with two vinyl and two propionic acid side chains. Heme is biosynthesized in both the bone marrow and the liver.
JaundiceJaundice, also known as icterus, is a yellowish or, less frequently, greenish pigmentation of the skin and conjunctivae due to high bilirubin levels. Jaundice in adults typically indicates the presence of underlying diseases involving abnormal hememetabolism, liver dysfunction, or biliary-tract obstruction. The prevalence of jaundice in adults is rare, while jaundice in babies is common, with an estimated 80% affected during their first week of life.
PorphyrinPorphyrins ( POR-fər-ins) are heterocyclic, macrocyclic, organic compounds, composed of four modified pyrrole subunits interconnected at their α carbon atoms via methine bridges (=CH−), so they are cyclic tetrapyrroles. In vertebrates, an essential member of the porphyrin group is heme, which is a component of hemoproteins, whose functions include carrying oxygen in the bloodstream.*As an Amazon Associate I earn from qualifying purchases.