wikipedia.com
Copper
Aaron Malone-Stratton
Biology 564
May 1, 2008
Physical and Chemical
Properties
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Atomic Number - 29
MW = 63.546
Solid
Hydrophilic
Ductile and good
conductivity
• Heat conductor
• Density
– 8.96 g cm-1
• Melting Point
– 1357.77 K
• Oxidation States
– +1, +2, +3, +4
Isotopes
• Natural
–
63Cu
, 65Cu
• Radio isotopes
– Multiple isotopes
• Short half-life
• 31s - 2.5d
– Used in research
Uses of Copper
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Antimicrobial surfaces
Coinage
Cookware
Wire and electronics
Piping
Metal alloys
– Over 400 types
• Biocides
– Fungi and algae
• Important in redox
enzymes
• Important ion in
haemocyanin
Mode of Entry - Environment
• Mining/refinement
runoff
• Industrial smoke
• Animal feed
• Brake dust
• E-waste
• Waste water through
degrading pipes
• Biocides
• Decaying plants
• Volcanoes
• Forest fires
– Agricultural Poison
– Water Purification
• CuS, Cu2S
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Reactivity and Chemical
Speciation
• React with air not water (pure water)
• Reactive with ammonia/oxygen and
chloride/oxygen solutions
• Copper oxide Cu2O
– 4Cu(s) + O2(g)  2Cu2O(s)
nyctourist.com
indospectrum.com
• Many other compounds (www.webelements.com)
Mode of Entry - Organism
• Gills
• Digestive tract
Mode Of Toxic Interaction
• Compete with Na+ for Na+/Ca2+
Exchangers
– Intestine
– Gills
lib.mcg.edu
Toxicity to Aquatic Life and
Toxic Effects
• Osmoregulation
– Swelling and disruption of epithelial cell of gill
– Kidney and liver damage
• Neurological/
developmental
disorders
– Cu binds instead
of other metals
– Binding sulfhydryl
of proteins
• Enzyme activation/
deactivation
De Boeck et al. 2007
Formation of Hydroxyl Radicals
• Cu2+, H2O2 (hydrogen peroxide),*O2 (superoxide)
– Haber-Wiess reaction and Fenton reaction
• Cu2+ + *O2-  Cu+ + O2
• Cu+ + H2O2  Cu2+ + OH- + *OH
• Free radicals cause damage to cells
Toxicity
Seawater
Stream
Human
• EPA Limit
– 1.3 ppm for drinking water
• Mugil cephalus (teleost)
– LC50 96h 5 mg/L
– 10 mg/L = 100% mortality
• Squalus acanthias (elasmobranch)
– LC50 96h 800-1000 ug/L
• Cancer magister (crustacean)
– LC50 96h 0.1 mg/L
ppb by weight
3
6
1000
Metabolism and Breakdown
• 15% used in diet
– Enzyme Activity
• 85% sequestered (liver) or excreted
Glutathione
wikipedia.com
• High abundance in cells (liver)
• Reduced form (GSH) 90% abundance
– Reacts with Cu to form GS-Cu
– H+ donated to reactive oxygen species
– Sequesters free copper
• Oxidized form (GSSG) 10% abundance
– GSSGGSH (glutathione reductase)
Metallothionein (MT)
• Metal induces production of protein
– Transport of metals
• 2 cystine-rich areas (metal binding site)
• Releases bound metals upon oxidation of
cystine residues
– Bind excess metal
• Excrete or storage???
• Transfer of Cu from GS to MT
– Via GS-Cu-MT complex
Menkens ATPase Pump
• Copper induced activity
• Most excreted through bile not urine
• Mechanism of acquiring metal unknown
– Low free copper in cell
Defense
• Sodium in diet - reduce binding to gills
lib.mcg.edu
References
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copper.org
webelements.com
Copper - Environmental Literacy Council
(http://www.enviroliteracy.org/article.php/1029.html)
Agency for Toxic Substances and Disease Registry. Copper. CAS # 744050-8. 2004.
Zyadah M.A., Abdel-Baky T.E. (2000) Toxicity and Bioaccumulation of
Copper, Zinc, and Cadmium in Some Aquatic Organisms. Bull. Environ.
Contam. Toxicol. 64:740-747
De Boeck G., Grosell M., Wood C. (2001) Sensitivity of the spiny dogfih
(Squalus acanthias ) to waterborne silver exposure. Aquatic Toxicology 54:261275
Kang J. (2006) Metallothionein Redox Cycle and Function. Experimantal Biology
and Medicine 231: 1459-1467
Koppenol W. H. (2001) The Haber-Weiss Cycle - 70 years later. Redox Report
Vol. 6 229-234
Mason A.Z., Jenkins K.D. (1995) Metal Detoxification in Aquatic Organisms.
Metal Speciation and Bioavailability in Aquatic Systems. 479-608
References
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Mason A., Moeller R., Thrippleton K., Lloyd D. (2007) Use of stable isotopically
enriched proteins and directly coupled high-performance liquid chromatography
inductively coupled plasma mass spectrometry for quantitatively monitoring the
transfer of metals between proteins. Analytical Biochemistry 396: 87-104
Wijmenga C., Klomp L. W. J. (2004) Molecular regulation of copper excretion in
the liver. Proceedings of the Nutrition Society. 63: 31-39
Rauch H., Wells A.J. (1989) Hepatic metallothionein turnover in toxic milk
mutant mice. FASEB Journal. 3:3
Klassen C., Choudhuri S., McKim Jr. J.,Lehman-McKeeman L., Kershaw W.
(1994) In Vitro and In Vivo Studies on the Degradation of Metallothionein.
Environmental Health Perspectives. 102
Dameron C., Harrison M. (1998) Mechanisms for protection against copper
toxicity. Am. J. Clin. Nutr. 67(suppl) 1091S-7S
Independent Contractor of INCA (1989) Final Report INCA Project No. 223
The Biological Importance of Copper, A Literature Review.