Alkaline phosphatase: An enzyme that liberates phosphate under alkaline conditions and is made in liver, bone, and other tissues. Alkaline phosphatase can be measured in a routine blood test. Abnormally high serum levels of alkaline phosphatase may indicate bone disease, liver disease, or bile duct obstruction.
Alkalosis: Relatively too much base in the blood and body, an abnormal condition resulting from the accumulation of base or the depletion of acid. The pH of an alkalotic body measures above normal. The opposite of alkalosis is acidosis.
A genetic metabolic disorder due to deficiency of the enzyme homogentisic acid (HGA) dioxygenase. Deficiency of this enzyme leads to the three cardinal features of alkaptonuria (the presence of homogentisic acid in the urine), ochronosis (bluish-black pigmentation in connective tissue), and arthritis. Urine that turns dark is a characteristic feature.
- Alkyl group
Alkyl group: In chemistry, a group of atoms derived from an alkane (a hydrocarbon with no carbon-to-carbon multiple bonds) by the loss of a hydrogen atom.
Allelic: Pertaining to an allele, an alternative form of a gene. A single allele is inherited from each parent.
Allergen: A substance that can cause an allergic reaction. Common allergens include ragweed pollen, animal dander, and mold.