Micronutrients Part 4 Flashcards
What is the fourth group of micronutrients? What are some examples?
- Essential trace minerals
- Iron, Copper, Zinc
what are the two forms of iron?
- heme
-non-heme
what are the characteristics of non-heme iron?
what two processes convert ferric iron into ferrous iron?
- bound to proteins, cleaved by HCL and proteases in the stomach
1. stomach acid
2. reductase enzyme in the small intestine
What are some characteristics of heme-iron?
- bound and released from hemoglobin/ myoglobin
- porphyrin ring is broken down into Fe2+
in what form is iron transported? it it important for iron to be bound?
- ferrous (oxidized) iron
- bound to transferrin, a carrier protein
- yes, otherwise can accelerate production of ROS
where is iron stored?
liver
what is the readily available storage of iron?
- ferritin-Fe3+
What molecules can convert stored ferritin-Fe3+ to ferrous iron?
- any electron donator
- vit c, nadh, fadh
there are 6 ferrous iron molecules. how many transferrin proteins are needed to carry these molecules through the blood?
- 3 transferrin (2 binding sites)
where are the components of red blood cells degraded and recycled?
- spleen
(hemoglobin degradation)
what is metallothionein?
- an inhibitor chelator
- binds to ANY metal ions present
- metallothionein is formed by high levels of any metal ions
- therefore high intake of one metal ion can cause the lack of absorption of another!
what is main purpose ceruloplasmin?
- supports copper and iron metabolism
A person has a copper excess. what is one way to reverse this?
- chelation therapy
–> consume more zinc to produce metallothionein
What is the most common transporter of micronutrients? what is an exception?
- albumin
-iron (uses transferrin)
What is zinc’s role in gene expression?
allows for basic amino acids to interact with DNA
TRUE OR FALSE:
excess zinc intake can contribute to delayed sexual maturity
FALSE:
- a DEFICIENCY in zinc intake can contribute to delayed sexual maturity (due to a lack of testosterone synthesis)
