concentration. Glass electrodes are
used in pH measurement.
glass Übres Melted glass drawn
into thin Übres some 0.005 mm–0.01
mm in diameter. The Übres may be
spun into threads and woven into
fabrics, which are then impregnated
with resins to give a material that is
both strong and corrosion resistant.
It is used in car bodies, boat building,
and similar applications.
glauberite A mineral consisting of
a mixed sulphate of sodium and calcium, Na 2 SO 4 .CaSO 4 .
Glauber’s salt *Sodium sulphate
decahydrate, Na 2 SO 4 .10H 2 O, used as
a laxative. It is named after Johann
Glauber (1604–68).
GLC (gas–liquid chromatography)
See gas chromatography.
global warming See greenhouse
effect.
globin See haemoglobin.
globular protein See protein.
globulin Any of a group of globular
proteins that are generally insoluble
in water and present in blood, eggs,
milk, and as a reserve protein in
seeds. Blood serum globulins comprise four types: α 1 -, α 2 -, and βglobulins, which serve as carrier proteins; and γ-globulins, which include
the immunoglobulins responsible for
immune responses.
glove box A metal box that has
gloves Ütted to ports in its walls. It is
used to manipulate mildly radioactive materials and in laboratory
techniques in which an inert, sterile,
dry, or dust-free atmosphere has to
be maintained.
glow discharge An electrical discharge that passes through a gas at
low pressure and causes the gas to
become luminous. The glow is produced by the decay of excited atoms
and molecules.
gluconic acid An optically
active hydroxycarboxylic acid,
CH 2 (OH)(CHOH) 4 COOH. It is the carboxylic acid corresponding to the aldose sugar glucose, and can be made
by the action of certain moulds.
glucosan Any one of a class of
*polysaccharide compounds that can
be converted to glucose by hydrolysis. Glucosans include dextrin, starch,
and cellulose.
glucose (dextrose; grape sugar) A
white crystalline sugar, C 6 H 12 O 6 , occurring widely in nature. Like other
*monosaccharides, glucose is optically active: most naturally occurring
glucose is dextrorotatory. Glucose
and its derivatives are crucially important in the energy metabolism of
living organisms. Glucose is also a
constituent of many polysaccharides,
most notably starch and cellulose.
These yield glucose when broken
down, for example by enzymes during digestion.
glucuronic acid A compound,
OC 6 H 9 O 6 , derived from the oxidation
of glucose. It is an important constituent of gums and mucilages. Glucuronic acid can combine with
hydroxyl (–OH), carboxyl (–COOH), or
amino (–NH 2 ) groups to form a glucuronide. The addition of a glucuronide group to a molecule
(glucuronidation) generally increases
the solubility of a compound; hence
glucuronidation plays an important
role in the excretion of foreign substances.
glucuronide See glucuronic acid.
glutamic acid See amino acid.
glutamine See amino acid.
glutaric acid See pentanedioic
acid.
247
glutaric acid
g
www.AzShimi.ir www.AzShimi.com
used in pH measurement.
glass Übres Melted glass drawn
into thin Übres some 0.005 mm–0.01
mm in diameter. The Übres may be
spun into threads and woven into
fabrics, which are then impregnated
with resins to give a material that is
both strong and corrosion resistant.
It is used in car bodies, boat building,
and similar applications.
glauberite A mineral consisting of
a mixed sulphate of sodium and calcium, Na 2 SO 4 .CaSO 4 .
Glauber’s salt *Sodium sulphate
decahydrate, Na 2 SO 4 .10H 2 O, used as
a laxative. It is named after Johann
Glauber (1604–68).
GLC (gas–liquid chromatography)
See gas chromatography.
global warming See greenhouse
effect.
globin See haemoglobin.
globular protein See protein.
globulin Any of a group of globular
proteins that are generally insoluble
in water and present in blood, eggs,
milk, and as a reserve protein in
seeds. Blood serum globulins comprise four types: α 1 -, α 2 -, and βglobulins, which serve as carrier proteins; and γ-globulins, which include
the immunoglobulins responsible for
immune responses.
glove box A metal box that has
gloves Ütted to ports in its walls. It is
used to manipulate mildly radioactive materials and in laboratory
techniques in which an inert, sterile,
dry, or dust-free atmosphere has to
be maintained.
glow discharge An electrical discharge that passes through a gas at
low pressure and causes the gas to
become luminous. The glow is produced by the decay of excited atoms
and molecules.
gluconic acid An optically
active hydroxycarboxylic acid,
CH 2 (OH)(CHOH) 4 COOH. It is the carboxylic acid corresponding to the aldose sugar glucose, and can be made
by the action of certain moulds.
glucosan Any one of a class of
*polysaccharide compounds that can
be converted to glucose by hydrolysis. Glucosans include dextrin, starch,
and cellulose.
glucose (dextrose; grape sugar) A
white crystalline sugar, C 6 H 12 O 6 , occurring widely in nature. Like other
*monosaccharides, glucose is optically active: most naturally occurring
glucose is dextrorotatory. Glucose
and its derivatives are crucially important in the energy metabolism of
living organisms. Glucose is also a
constituent of many polysaccharides,
most notably starch and cellulose.
These yield glucose when broken
down, for example by enzymes during digestion.
glucuronic acid A compound,
OC 6 H 9 O 6 , derived from the oxidation
of glucose. It is an important constituent of gums and mucilages. Glucuronic acid can combine with
hydroxyl (–OH), carboxyl (–COOH), or
amino (–NH 2 ) groups to form a glucuronide. The addition of a glucuronide group to a molecule
(glucuronidation) generally increases
the solubility of a compound; hence
glucuronidation plays an important
role in the excretion of foreign substances.
glucuronide See glucuronic acid.
glutamic acid See amino acid.
glutamine See amino acid.
glutaric acid See pentanedioic
acid.
247
glutaric acid
g
www.AzShimi.ir www.AzShimi.com