Module 1: Minerals

Question 1

Zinc percentage normal absorption
Via which transporter?

Answer 1

30% absorption, 2-3g stored in tissues, RDA 10-15mg
Absorption in the duodenum and jejunum via ZIP4 transporter

Different types of Zn receptors in different organ systems

Question 2

Zinc biological involvements and functions

Answer 2

Heavy metal involved in: carbohydrate metabolism, wound healing, immune function, inflammation and oxidative stress

Functions:
1) protein structure stabilization, ex. TF zinc finger motif)
2) catalysis
3) regulation of gene expression

Question 3

Percent zinc distribution

Answer 3

60% goes to muscles and 30% goes to bones via ZIP13

Question 4

Selenium is part of which non-standard AA?

Answer 4

selenocysteine - component of glutathione peroxidase and other antioxidants
selenomethionine

Question 5

Selenium function

Answer 5

acts as cofactor for antioxidants: glutathione peroxidase, thioredoxin reductase iodothyroninedeiodinase

toxic in excess

Question 6

About iron

Answer 6

transition metal
used as a prosthetic group by things involved with O2:
hemoglobin, myglobin, cytochrome c, peroxidases, hydroxylases

Question 7

Structure of hemoglobin

Answer 7

4 subunits (2 alpha, 2 beta)
Requires iron for functional heme group along with histidine coordinates carrying oxygen

Question 8

Iron content in the body and requirements

Answer 8

Av. daily intake: ~15mg (2mg absorbed)
Body contains 3-4g of iron, 60% in blood

Question 9

How is iron lost?

Answer 9

occult losses (through intestine), skin shedding, menstruation and lactation

Question 10

Iron deficiency about

Answer 10

80% are iron deficient
Anemia symptoms: pale skin, shortness of breath, fatigue, poor temp maintenance, inflamed tongue, poor cognition, decreased immune function
Anemia occurs in alcoholics, infections, inflammatory or neoplastic (cancerous) disease

Question 11

Iron excess about

Answer 11

Genetic: African/hereditary hemochromatosis, porphyria (decreased heme, increase porphyrins), hyperferritinemia (increased iron storage as ferritin)

Question 12

secondary hemochromatosis

Answer 12

due to excessive alcohol or iron supplementation

Question 13

Iron excess causes

Answer 13

damage to liver, pancreas, and adrenals

hypothyroidism, impotence, cardiac dysfunction, pigmentation

Question 14

Types of thyroid hormones
Receptor

Answer 14

T3 - triiodothyronine (3 iodine) and T4 - thyroxine (4 iodine)
T3R nuclear receptor type II (RXR Heterodimer)

Question 15

Iodine is necessary for

Answer 15

thyroid health and production of thyroid hormone (T3/T4)
Presence or absence of thyroid hormones to bind nuclear receptors (iodine dependent) will affect transcriptional activity

Question 16

Iodine sources

Answer 16

Kelp, seafood, iodized salt, dairy

Question 17

Iodine deficiency symptoms

Thyroid related disorders (secondary)

Answer 17

infant mortality, neurological defects, retardation (cretinism), decreased reproduction, hypothyroidism, goiter

anemia, arthritis, eye enlargement/inflammation, hair loss, premature greying, IBS, depression

Question 18

What is goiter?
How is it caused?

Answer 18

Goiter is caused by impaired thyroid hormone production (due to iodine deficiency) which leads to increased thyroid cell production to try and produce more hormone (which it can’t)

Goiter can also be from excess iodine which results in inhibition of thyroid production

Can be caused by selenium deficiency bc Se acts as cofactor for iodothyroninedeiodinases

Question 19

Sodium role

Answer 19

Major role in absorption and transport of nutrients, blood pressure and water balance based on electrochemical gradients

Nerve signal conduction and muscle contraction/relaxation

Question 20

Sodium intestinal transport role absorption and secretion for fluid balance

Answer 20

Fluid Balance:
1) Active transport of Na across basolateral cell membrane via Na/K ATPase to ensure transport of Cl- and water into bloodstream (passive Na transport on apical side)
2) Passive transport of Na+ and K+ and water, with active transport of Cl- NKCC transporter (basolateral) and apical transport channels

Question 21

Na involvement in glucose absorption

Answer 21

Glucose Absorption:
In intestine 1) Apical SGLT1 co-transport of 2Na+ and glucose into enterocytes and
2) Basolateral GLUT 2 glucose transporter and simultaneous Na+ via channels

In kidney SGLT1/SGLT2 reabsorption of glucose
SGLT2 1:1 ratio of absorbance (lower affinity)

Question 22

Highest source of Na in food?

Answer 22

Bakery products, prepared foods, processed meats
Especially high intake with men

Question 23

Ca, Na and K as a signaling molecule in taste

Answer 23

Ca, K and Na acts as signaling molecules in taste receptors conveying signal to cellular machinery

Question 24

Ca IP3 signaling pathway tastes

Answer 24

L-glutamate and glycine bind umami receptor
Sucrose/fructose/artificial sweeteners bind sweet receptor
- b/c aspartame can bind to sweet receptor it is perceived as sweet
Quinine, denatonium and salicin bind bitter receptor

Question 25

Zinc transporters intestines, skin/bone, brain, mammary glands, and pancreas

Answer 25

Intestines: ZIP4
Skin/Bone: ZIP13
Mammary Glands: ZnT2
Pancreas: ZnT8
Brain: ZnT10