Category: I

Different forms of an enzyme, usually occurring in different tissues. The isoenzymes of a particular enzyme catalyze the same reaction but they differ in some of their properties. Enzymes that have the same catalytic activity, but different structures, properties, and/or tissue distribution. A physically distinct form of a given enzyme. Isoenzymes catalyze the same type…

An atom or group of atoms that have a positive or negative electric charge due to a gain (negative charge) or loss (positive charge) of one or more electrons. Atoms with a positive charge are known as cations; those with a negative charge are anions.  

The movement of ions across energy-transducing cell membranes. Transport can be active or passive. Passive ion transport (facilitated diffusion) derives its energy from the concentration gradient of the ion itself and allows the transport of a single solute in one direction (uniport). Active ion transport is usually coupled to an energy-yielding chemical or photochemical reaction…

Reaction occurring without intention or volition. Done automatically, without any conscious thought or decision-making being involved. Done without conscious thought or control of the will. An event that happens without conscious intention.  

Animals that have no spinal column. An animal without a backbone. The following are invertebrate groups of medical importance: insects, ticks, nematodes, flukes, protozoans, and tapeworms.  

Non-coding, intervening sequences of DNA that are transcribed, but are removed from within the primary gene transcript and rapidly degraded during maturation of messenger RNA. Most genes in the nuclei of eukaryotes contain introns, as do mitochondrial and chloroplast genes. Segment of a gene that is transcribed but then removed from the primary transcript by…

Situated entirely within or pertaining exclusively to a part. Refers to the essential nature of a substance or structure. Within the individual arising inside the mind or the body, extrinsic. Belonging to the essential nature of an organism, or entirely within an organ or part. Belonging to the essential nature of a thing. It is…

Within a vessel or vessels. Within the vascular tree. An intravascular (IV) injection is one where a substance is injected into a vein.  

Within the eye. Between the cornea and the lens of the eye.