Hematopoietic nutrients

Question 1

Hematopoietic vits and minerals

Answer 1

-folic acid
-vit B12
-Iron

Question 2

Function of Folic acid and Vit B12

Answer 2

Involved in single carbon transfers as catalysts
*carbon not donors

Question 3

Function of Fe

Answer 3

Involved in oxidation reduction reactions and heavily involved in RBC metabolism
-role in hemoglobin and O2 binding capacity
-role in myoglobin (draws O2 from hemoglobin in the blood to muscles)
-role in heme-proteins

Question 4

Vitamin B12 structure and synthesis

Answer 4

Cyanocobalamin
-ring structure with cobalt ion in middle (only Co function)
-synthesized by bacteria and yeast; not present in plant products

Question 5

Methionine synthase

Answer 5

Conversion of homocysteine to methionine allowing for the reduction of folate for recycling
*need both B12 and folate

Question 6

Folate and B12 deficiencies

Answer 6

Look similar, can only tell difference by treating with folate
-if animal gets better than caused by lack of folate
-if animal does not get better, than B12 was the issue as folate can’t be recycled

Question 7

What is seen with B12 deficiency

Answer 7

Pernicious or megaloblastic anemia (large, immature RBCs in blood)

Question 8

Heritable B12 deficiency in humans

Answer 8

Sprue= lack of intrinsic factor

Question 9

Cobalt supplementation in ruminants

Answer 9

Benefit because it allows for the microbes to synthesize B12

Question 10

Folic acid

Answer 10

Vit B9
-abundant in plant sources
-required for methionine and DNA synthesis

*Same kinetics as thiamin

Question 11

Folate deficiency

Answer 11

Megaloblastic anemia
-common B vit deficiency in humans
-can result in spina bifida defects in humans
-causes anemia, stunted growth, weight loss, increased clotting time in animals

Question 12

Two key factors of Fe biochemistry

Answer 12

1. Low solubility
2. Redox characteristics

Question 13

Fe in aqueous aerobic environment

Answer 13

Occurs as Fe3+

Question 14

Fe in physiological conditions

Answer 14

Occurs as both Fe 3+ and Fe2+

Question 15

What are some important areas in which you can find Fe?

Answer 15

Question 16

What form is iron in in the acidic environment of the stomach?

Answer 16

Fe2+

Question 17

Intestinal absorption of Fe

Answer 17

Poor (2-5%)
-need divalent metal transporter 1 (DMT1)
-phytates and other dietary factors= decrease absorption
-Vit C/chelated Fe forms=increased absorption

Question 18

What regulates Fe absorption?

Answer 18

DMT1 synthesis

Question 19

Fe absorption

Answer 19

1. Transferrin transports iron in plasma
2. Fe2+ released to Ferritin in cell and transported to the basolateral membrane by the Feroportin. Ferritin stores iron in liver, spleen, bone marrow cells
3. No excretion mechanism other than losses (bleeding, intestinal sloughing)
   *excess iron will precipitate in cells as hemosiderin

Question 19

Two main functions of Lactoferrin

Answer 19

1. Excreted in milk to bind iron in gut of neonates
2. Prevent bacterial infections

Question 20

Lactoferrin during infection

Answer 20

1. Secreted by liver
2. Lactoferrin will bind with Fe in the body and return it to the liver to be stored as ferritin
   -prevents availability of Fe for bacteria

Question 21

Competition between host and bacteria for Fe

Answer 21

Free Fe is rare in body
-always associated with carrier proteins
-bacteria grab iron by producing sideophore-iron binding proteins
-animals compete with lactoferrin (which also has antimicrobial and antiinflammatory effects)

Question 22

Iron toxicity

Answer 22

Rare
-causes anorexia, weight loss, decreases serum albumin, hepatic dysfunction and hemosiderosis

Question 23

Hemochromatosis

Answer 23

Genetic disease in humans where iron is over absorbed from diet
-causes joint pain, liver disease, heart abnormalities, abnormal pigmentation of skin (looks gray, bronze)

Question 24

Iron content of feeds

Answer 24

-oilseeds and pulses higher than cereal grains
-animal source iron and forage iron is mostly unavailable

Question 25

Iodine

Answer 25

-absorbed by small intestine by passive diffusion
-high concentration of iodine in thyroid
-iodine in feed depends on soil iodine levels

Question 26

Iodine function

Answer 26

1. Component for T3 (triodothyronine) and T4 (thyroxin/tetraiodothyronine)
2. Controls basal metabolism including thermoregulation, intermediary metabolism, reproduction, growth and development

Question 27

Iodine deficiency

Answer 27

Classically causes goiter (swelling on neck from thyroid enlargement)
*iodized salt often a preventative

Question 28

Brassicas and Goitrogens

Answer 28

Cabbage, broccoli, mustard, canola (rapeseed)
-contain glucosinolates and myrosinase

-Myrosinase converts glucosinolates to compounds with goitrogenic properties (goitrin)
-Goitrin prevents oxidation of iodine that blocks T3 and T4 formation

Question 29

Canola

Answer 29

Low glucosinolate varieties of rapeseed