CADD SeeCOMPUTER-ASSISTED DRUG DESIGN.
cage Aggregate of molecules, generally in the con-
densed phase, that surrounds the fragments formed, for
example, by thermal or photochemical dissociation.
Because the cage hinders the separation of the frag-
ments by diffusion, they may preferentially react with
one another (“cage effect”) but not necessarily to re-
form the precursor species. For example
R–NN–R, heat →[R.+ N 2 + R.]cage →R–R + N 2
See alsoGEMINATE RECOMBINATION.cage compound A polycyclic compound having the
shape of a cage. The term is also used for INCLUSION
COMPOUNDs.
calmodulin A Ca2+ binding protein involved in
METABOLIC REGULATION.
See alsoEF-HAND; HELIX.
calorie An energy measurement unit; the amount of
energy required to raise the temperature of 1 gram of
water by 1°C, equal to 4.1868 joules. The term Calorie
(capitalized) is used in food science to represent a kilo-
calorie (1,000 calories) to describe the energy content
of food products.
calorimeter An instrument used to measure quanti-
ties of heat.calpain A calcium-activated neutral protease.Calvin, Melvin (1911–1997) American Chemist
Melvin Calvin was born on April 8, 1911, in St. Paul,
Minnesota. He received a B.S. degree in chemistry in
1931 at the Michigan College of Mining and Technol-
ogy and a Ph.D. degree in chemistry from the Univer-
sity of Minnesota in 1935. He conducted postdoctoral
studies in England and then began his academic career
as an instructor at the University of California at
Berkeley in 1937 and as a full professor from 1947
until his death in 1997. He served as director of the
big-organic chemistry group in the Lawrence Radiation
Laboratory beginning in 1946. This group became the
Laboratory of Chemical Biodynamics in 1960.
Calvin is the man known to have unlocked the
secrets of photosynthesis. Calvin received the 1961
Nobel Prize in chemistry for identifying the path of car-
bon in photosynthesis. Shortly thereafter he established
the Chemical Biodynamics Division (now Structural
Biology Division), which he directed for 20 years.
Using carbon-14 isotope as a tracer, Calvin and his
research team mapped the complete route that carbon
travels through a plant during photosynthesis, begin-
ning with its absorption as atmospheric carbon dioxide
to its conversion into carbohydrates and other organic37