Category: X

From the Greek word xenos, meaning “stranger.” Xenogeneic literally means “strange genes.” Refers to genetically engineered (e.g., “humanized”) organs that have been grown within an animal of another species. For example, several companies are working to engineer and grow—inside swine—a number of organs to be transplanted into humans that need those organs (e.g., due to…

Those compounds (e.g., veterinary drugs, agrochemical herbicides, etc.) that are designed to be used in an ecosystem comprised of more than one species. For example, herbicides intended to kill weeds but leave commercial crops undamaged or veterinary drugs that are intended to kill parasitic worms but leave the host livestock unharmed.  

The use of diffraction patterns produced by X-ray scattering from crystals (of a given material’s molecules) to determine the three-dimensional structure of the molecules.  

A sex chromosome that usually occurs paired in each female cell, and single (i.e., unpaired) in each male cell in those species in which the male typically has two unlike sex chromosomes (e.g., humans). A sex-determining chromosome present in all of a female’s ova and in one-half of a male’s sperm. The fertilization of an…

Plants that can grow or survive in a medium of very low humidity.  

Pentose (five-carbon) sugar found in plant tissues as complex polysaccharide; 40% as sweet as sucrose. Also known as wood sugar. Pentose which has not been metabolised. A pentose sugar (i.e. one with five carbon atom’s) that is involved in carbohydrate interconversions within cells. A sugar containing five carbon atoms involved in the metabolic conversion of…

A five-carbon sugar; said to have an effect in suppressing the growth of some of the bacteria associated with dental caries. Sugar-alcohol (polyol). A five-carbon sugar alcohol that has a sweet taste and has chemical properties similar to those of sucrose. It may be used in place of sucrose as a sweetener. The use of…

Yellowing of the skin associated with high blood concentrations of carotene. Yellow colouring of the skin, caused by eating too much food containing carotene. Abnormal yellowish discoloration. A yellowing of the skin seen in carotenemia resulting from ingestion of excessive quantities of carrots, squash, egg yolk, and other foods containing carotenoids. The condition is usually…

Yellow-orange hydroxylated carotene derivatives. The yellow-orange pigments found in plant foods such as corn, peaches and squash. A yellow pigment found in green leaves. An example of a xanthophyll is lutein. A yellow pigment derived from carotene. It is present in some plants and egg yolk.