GLOSSARY 



93 



goes complete metamorphosis (egg — » larva — > 

 pupa — »adult). 



homogenate: Ideally, a cell-free suspension ob- 

 tained by grinding tissues in such a way that 

 cell structure is destroyed. 



hydroqulnone: A reducing agent used to reduce 

 cytochrome c. 



Krebs cycle: See citric acid cycle. 



larva: Immature, wingless, generally worm- 

 like form into which holometabolous insects 

 hatch from the egg and in which they remain 

 until they change into pupae. 



liver: See midgut gland. 



malonate: The salt of malonic acid; a dicarbox- 

 ylic acid that competitively inhibits the oxida- 

 tion of succinic acid. 



Malpighian tubules: Tubular organs opening 

 into the midgut or hindgut of insects; gener- 

 ally believed to be excretory in function. 



mantle: In mollusks, the fold of the body wall 

 which, in shell-bearing forms, lines and 

 secretes the shell. 



microsomes: An operational term referring to 

 the fraction obtained when homogenates freed 

 of large particulate matter are centrifuged 

 at high centrifugal forces; the fraction ob- 

 tained is composed essentially of fragments 

 of ruptured endoplasmic reticulum (see defi- 

 nition) and its attached particles. 



midgut gland: Name preferred by many inver- 

 tebrate zoologists for the digestive gland of 

 mollusks and crustaceans; in mollusks, some- 

 times called hepatopancreas, digestive diver- 

 ticula, or liver; in crustaceans, often called 

 hepatopancreas or liver. 



mitochondria: Intracellular particles (average 

 diameter, 1^) containing the enzymes and co- 

 enzymes that comprise the electron trans- 

 port system; involved in oxidative phosphory- 

 lation, and citric and fatty acid oxidations; 

 can be collected in a relatively homogeneous 

 fraction by centrifugation (at 5000 x ^) of a 

 homogenate from which nuclei and cellular 

 debris have been removed by a low-speed 

 centrifugation. 



molt: A term frequently used, as in this volume, 

 to indicate the growth processes undergone 

 by arthropods both before and after ecdysis, 

 as well as during ecdysis. 



nymph: Immature stage into which hemimetab- 

 olous insects hatch from the egg. 



optical density: See absorbancy. 



oxidative phosphorylation: The process by 

 which adenosine diphosphate (A DP) and inor- 

 ganic orthophosphate are converted to the 

 high-energy compound adenosinetriphosphate 

 (ATP); energy for this conversion is derived 

 from the transport of electrons through the 

 terminal electron transport system. 



pallial: Refers to the mantle, especially of a 

 moUusk. 



particulate fraction: Any of several fractions 

 that are usually obtained from a tissue homog- 

 enate by differential centrifugation. 



pedal retractor: In mollusks, a muscle that re- 

 tracts the foot. 



perienteric: Refers to the cavity that surrounds 

 the digestive tract. 



/)-phenylenediamine: A reducing agent used to 

 reduce cytochrome c. 



P/0 ratio: Ratio of inorganic phosphate esteri- 

 fied (to ATP) to the oxygen consumed during 

 the aerobic oxidation of a metabolite; denotes 

 the efficiency of utilization of energy made 

 available by the transfer of electrons through 

 the electron transport system. 



polarograph: An instrument used in polarog- 

 raphy, which is concerned with oxidation- 

 reduction reactions at an electrode. If poten- 

 tials are measured while known currents are 

 flowing through the cell, and these two param- 

 eters are plotted against each other, a curve 

 is obtained from which the character and con- 

 centration of a given material can be ascer- 

 tained. 



pupa: The intermediate, quiescent form as- 

 sumed by holometabolous insects following 

 the larval stage, or stages, and prior to the 

 adult stage. 



quinol: See hydroqulnone. 



radula: A chitinous, tooth-bearing ribbon used 

 by mollusks, exclusive of bivalves, for rasping 

 food into minute particles. 



respiratory quotient: Ratio of the volume of 

 carbon dioxide produced to the volume of ox- 

 ygen consumed during respiration. 



retractor muscle of foot: See pedal retractor. 



sarcosomes: Mitochondria of muscle. 



Slater factor: A component of the electron trans- 

 port chain operative between cytochrome b 

 and cytochrome c; inhibited by antimycin A. 



spectrophotometer: An instrument for the quan- 

 titative measurement of the transmission of 

 light of a given wave length through a solution. 



