Minerals

Question 1

What is a disease of iron overload caused by a mutation in the hepcidin gene?

Answer 1

Hemochromatosis

Question 2

What protein binds calcium and enables it to serve as a second messenger?

Answer 2

Calmodulin

Question 3

How is iron transported in the blood?

Answer 3

Iron is oxidized to the ferric form by hephastin and transported by transferrin.

Question 4

What protein controls iron content in the body? How?

Answer 4

Hepcidin is produced by the liver and inhibits the ferroportin

Question 5

Cardiac failure, liver disease, cancer, atherosclerosis, hair
loss, skin changes, and infertility are associated with a deficiency of what mineral?

Answer 5

Selenium

Question 6

How is iron stored in the body?

Answer 6

Iron is stored in ferritin

Question 7

What symptoms are associated with excess selenium?

Answer 7

Peripheral neuropathy, nausea, diarrhea,
dermatitis, hair loss, nail deformities

Question 8

How is iron uptake into cells and tissues?

Answer 8

An iron-transferrin complex binds to the cell. The complex is endocytosed in a clatherin coated-pit to form an endosome. Protons are pumped into the endosome, allowing iron to dissociate from transferrin. Iron is released from the endosome via DMT1 and transferrin returns to the cell surface.

Question 9

In heme form, iron plays an important role in transportation of O2/CO2. What is the role of iron-sulfur clusters?

Answer 9

Electron transport chain and ATP synthesis

Question 10

What diseases are associated with calcium deficiency?

Answer 10

Children - rickets
Adults - osteoporosis

Question 11

Poor growth and testicular atrophy in children is associated with deficiency of what mineral?

Answer 11

Zinc - in adults presents with dermatitis, poor wound healing, hair loss, decreased taste

Question 12

What inorganic ions act as electrolytes?

Answer 12

Sodium, potassium, chloride

Question 13

Spontaneous, asynchronous, and involuntary muscle contractions may be associated with what mineral-related disorder?

Answer 13

Hypocalcemia

Question 14

What is the cellular response to low iron levels via transferrin and ferritin?

Answer 14

When iron is low, IRPs bind the 3’ IRE of transferrin mRNA to stabilize the mRNA and promote translation. IRPs will bind the 5’ IRE of ferritin mRNA to prevent translation as there is not enough iron within the cell for storage.

Question 15

What is Menkes Syndrome? What are symptoms of the disease?

Answer 15

Copper deficiency causing growth retardation, mental deficiency, seizures, aneurysm, and bone demineralization.

Question 16

How is zinc absorbed in the diet? Where is zinc stored?

Answer 16

Absorbed in the small intestine from meats, nuts, and beans. Zinc is stored in metallothionine

Question 17

What is the function of electrolytes?

Answer 17

Establish ion gradients, maintain water balance, neutralize charges

Question 18

What are the extracellular roles of calcium?

Answer 18

Structure/growth of bones and teeth, blood clotting, second messenger, electrical excitability of cell membranes

Question 19

What is the role of zinc in the body?

Answer 19

Metalloenzymes, zinc finger proteins that provide structure and regulate transcription

Question 20

How does the body respond to low calcium levels?

Answer 20

Release of parathyroid hormone increases to stimulate calcium release from bone, re-absorption in the kidney, and phosphate excretion. Vitamin D is synthesized to stimulate calcium absorption in the intestine.

Question 21

What mineral is only used for thyroid hormone synthesis?

Answer 21

Iodine

Question 22

Kidney stores are associated with excess of what mineral?

Answer 22

Calcium

Question 23

How is iron absorbed by intestinal cells?

Answer 23

As heme through a heme transported or in ferrous form through DMT1. Ferroportin allows passage of iron from the cell into the blood.

Question 24

True/False. Iron deficiency is one of the most common micronutrient deficiencies.

Answer 24

True. Low iron causes microcytic hypochromic anemia

Question 25

What cofactor is required for the reduction of the ferric iron to the ferrous iron?

Answer 25

Vitamin C

Question 26

What mineral is associated with antioxidant defense?

Answer 26

Selenium

Question 27

A patient presents with a gold ring around the cornea and neurological deterioration. What disease are they likely suffering from? What is the cause?

Answer 27

Wilson Disease due to copper overload because of a blocked biliary duct

Question 28

Iron needs are age- and gender-dependent. What populations generally require more iron?

Answer 28

Children, women, women who are menstruating, and women who are pregnant need more iron.

Question 29

This mineral is primarily responsible for assisting with Calcium absorption.

Answer 29

Copper

Question 30

What are the intracellular roles of calcium?

Answer 30

Second messenger, effect enzymes, regulate metabolism