Copper

Question 1

What are trace elements?

Answer 1

Inorganic elements with a physiological role in the body

Question 2

An element is considered a trace element when its requirement per day is below … mg

Answer 2

100

Question 3

Trace element deficiency

Answer 3

Rare but can be fatal

Question 4

Trace minerals (7)

Answer 4

Magnesium
Copper
Zinc
Fluoride
Chromium
Cobalt
Molybdenum

Question 5

What is the third most abundant trace mineral?

Answer 5

Copper

Question 6

What are the two forms of copper?

Answer 6

Cu+ and Cu2+

Question 7

Cu+

Answer 7

Cuprous ion

Question 8

Cu2+

Answer 8

Cupric ion

Question 9

Copper participates in … reactions

Answer 9

Redox

Question 10

Cu+ readily binds to … group in cysteine and methionine

Answer 10

Thiol group (-SH)

Question 11

Cu2+ associates with … group in aspartic/glutamic acid and imidazole N group in histidine

Answer 11

Secondary -COOH group

Question 12

Copper sources

Answer 12

Liver, kidney, shellfish, red meat, milk, chocolate, mushrooms, nuts and beans

Question 13

What food product contributes to 1/3 of copper intake in the UK?

Answer 13

Whole grain cereals

Question 14

Most adults have a sufficient intake of…

Answer 14

Copper

Question 15

High efficiency of … absorption in stomach and duodenum

Answer 15

Copper

Question 16

Dietary intake of copper is mainly in what form?

Answer 16

Cu2+

Question 17

What is unavailable to cells?

Answer 17

Cu2+

Question 18

Cu2+ is reduced to Cu+ in the cell wall via …

Answer 18

Reductase enzymes (DCYTb and STEAP)

Question 19

Cu+ is taken up into cells via what transport protein?

Answer 19

Copper transporter 1 (Ctr1)

Question 20

Cu2+ may also be transported into enterocyte via a … and subsequently reduced to Cu+

Answer 20

Low affinity pathway (mediated by DMT1 or endocytosis)

Question 21

Following absorption, Cu+ targeted towards …

Answer 21

Cuproproteins (CuPrs)

Question 22

What are the three routes for Cu+ to reach Cuproproteins (CuPrs)?

Answer 22

Cytosolic
Mitochondrial
Golgi

Question 23

Cytosolic route for Cu+ to Cuproproteins (CuPrs)

Answer 23

Copper chaperone for Sod1 (CCS) mediates copper loading and activation of superoxide dismutase (SOD) - antioxidant role

Question 24

Mitochondrial route for Cu+ to Cuproproteins (CuPrs)

Answer 24

Cox17 chaperones copper to Cox11 and Sco1/2 and subsequent incorporation into cytochrome c oxidase (CcO, a component of ETC) on the inner membrane of mitochondria

Question 25

Golgi route for Cu+ to Cuproproteins (CuPrs)

Answer 25

Atox1 chaperones copper to the Golgi apparatus for the synthesis of cuproproteins (metal response element on mRNA)

Question 26

Following absorption Cu+ is secreted into circulation via … on the basolateral membrane of the enterocyte

Answer 26

Atox1/ATPase (ATP7A)

Question 27

Normal serum copper concentration

Answer 27

109 ug / 100 ml

Question 28

90% of copper is bound to …

Answer 28

Ceruloplasmin

Question 29

10% of copper is bound to … and …

Answer 29

Plasma albumin and free amino acids

Question 30

Uptake of copper into peripheral tissues is via…

Answer 30

Ctr1

Question 31

Under normal conditions, total body copper is … mg

Answer 31

80

Question 32

Under normal conditions, highest copper concentrations are in …

Answer 32

Eyes Heart Liver Brain

Question 33

Copper is reduced by reductases such as … and …

Answer 33

STEAP and DCYTB

Question 34

Chaperons of copper

Answer 34

CCS Cox17 Atox1

Question 35

Chaperons of copper target Cu+ to … and …

Answer 35

SOD1 and CCO

Question 36

Metallothionines

Answer 36

MT1 and MT2

Question 37

Cuproproteins are assembled in Golgi compartment then … or …

Answer 37

Secreted out of cell or stored to specific organelles

Question 38

Elevated copper levels stimulate expression of MT1 and MT2, mediated by the transcription factors … and … to scavenge excess Cu+

Answer 38

MTF1 and Nrf2

Question 39

Copper can act as both a … and …

Answer 39

Pro-oxidant and antioxidant

Question 40

Free copper ions have the potential to generate …

Answer 40

ROS

Question 41

Excess Cu+ is sequestered by … in the cytosol in hepatocytes

Answer 41

Metallothioneins (MT1 and MT2)

Question 42

In other cells, copper is sequestered by …

Answer 42

Glutathione (GSH)

Question 43

Copper can be stored in … as a reservoir

Answer 43

Lysosomes

Question 44

What facilitates the export of Cu+ from the liver into systemic circulation

Answer 44

ATP7B

Question 45

Liver incorporates copper into …

Answer 45

Ceruloplasmin (CP)

Question 46

Ceruloplasmin (CP) is secreted into plasma to oxidise … to … to facilitate its absorption and mobilisation

Answer 46

Fe2+ to Fe3+

Question 47

Metabolic functions of copper

Answer 47

Component of enzymes Needed in synthesis of red and white blood cells Aids utilisation of iron (ceruloplasmin) Important for infant growth and brain development Immune function Strong bones

Question 48

Copper is cofactor to a variety of proteins

Answer 48

Copper/zinc superoxide dismutase (Cu/Zn SOD) Cytosome C oxidase Mitogen-activated protein kinase (MEK1) cAMP-degrading phosphodiesterase (PDE3B)

Question 49

Excess coppe can act as a … generating … thereby increasing oxidative stress

Answer 49

Pro-oxidant ROS

Question 50

Excess copper displace other metals in … causing impaired conformation and enzyme activity

Answer 50

Metalloproteins

Question 51

Most copper is excreted in bile via …

Answer 51

Copper transporting P-type ATPase (ATP7B)

Question 52

Amount of copper excreted is directly proportional to the size of the … to prevent systemic copper overload

Answer 52

Hepatic portal pool

Question 53

Small fraction of copper is excreted via …

Answer 53

Urine

Question 54

Copper deficiency

Answer 54

Extremely rare Menke’s disease - rare genetic condition Inability to absorb copper (ATP7A) Leads to severely impaired mental development, failure to keratinise hair, skeletal and vascular problems Diagnosed by low serum copper and low serum ceruloplasmin

Question 55

Copper toxicity

Answer 55

Very rare due to tight homeostatic control Wilson’s disease - rare genetic condition Inability to excrete excess copper in bile (via ATP7B) Leads to copper accumulation in liver and brain Gold or greenish gold rings appear around the irises (Kayser-Fleischer rings) Cardiomyopathy, renal tubular dysfunction, arthritis, hepatomegaly, CNS disorders follow first sign of Kayser-Fleischer rings

Question 56

Copper RNI

Answer 56

1.2mg/day