Unformatted text preview:

1 Metabolism 2 Exam 2 Iron1. What is Iron and where is it stored?- When you think of iron, think of hemoglobin and oxygen transport. The average adult has 2.5mg-3.5mg at any moment in their body, mostly in the form of hemoglobin and myoglobin. - There is an iron pool in the body that the body always has access to in the form of ferritin (how iron is stored in the body).  So it is used for hemoglobin synthesis, which is four heme groups, and myglobin synthesis, which is only one heme group. Hemeglobin serves to transfer oxygen throughout the body and myoglobin transfers oxygen in a certain muscle.- Iron is stored in the body while not in use as ferritin. Around 30% is stored as this (also in the form hemosiderin). This protein can hold up to 4500 iron atoms. Since this is the storage form, it is used to measure iron status.2. What is the function?- Iron is mainly for oxygen transport and also a coenzyme in many reactions involving energy metabolism, even in plants via photosynthesis. 3. What is the RDA?- Iron is set at 8mg for men and 15mg for women. It is higher in women due to menstrual bleeding, as iron is lost in blood. It is only higher for child bearing women; those past menopause are set at 8mg just like men. - Whenever she gives a ratio of mineral or vitamin/1000 kcal, know it. Iron is estimated at 5 mg per every 1000kcal in your diet. This means women have to basically consume 3000kcal to get the DRDA-not likely. Tony Berardi14. How is it classified and absorbed?- Depending on what source you ingest the iron from, it is either heme or non-heme iron.  Heme iron is always from animal meats, as you are ingesting the animal muscles that already have myoglobin and hemoglobin. So your body has no problem using this iron inthe form that it is in. So this iron requires no further reactions to be used. Non-heme iron is iron obtained in any other source. All minerals have to be realized from the food via HCl in the stomach—remember this from metab 1. So HCl is required in order to extract the non-heme iron from the food source. So acid will always increase absorption! Any situation to increase the acidic environment will increase absorption. Likewise, any situation that decreases the acidity will decrease absorption. - Ok, so now we have extracted the non-heme iron from the food source, what’s the next step? When bound to food, the iron is in the form of iron+++ or ferric form; this form is poorly absorbed. So now the ferric has to be reduced (GAIN and electron) to iron++ or the ferrous form. This is what the HCl actually does; it reduces it. This form is much more readily absorbed, thus why the acidic environment increases absorption.  Despite it being readily absorbed as ferrous, it is still only around 15% absorbed. 5. What affects the absorption?- So following the fact that an acidic environment will help ferric be reduced to ferrous, anything that increases the acidity of the stomach will increase absorption. Vitamin C greatly increases the acidity of the stomach, along with all the organic acids. MFP or meat, fish, and poultry factor always greatly increase the absorption, mainly from the cysteine concentration in them.  A general rule in the body is that if the body is in need of something, it will increase the absorption of it. So since ion is used to from hemoglobin in the blood, if you have a blood loss, your body loses all that iron and needs to replace it. Thus, it will increase the iron absorption. Also, pregnancy and the general rule is pregnancy increases everything, as you need nutrients for two people. - Then for factors that decrease absorption are anything that lowers the acidity of the stomach, such as achlorhydira (simply don’t produce acid). Phytate and oxalate are also Tony Berardi1seen for every mineral that decreases the absorption. Know the other weird ones, like coffee (due to polyphenols) and tea (due to tannins).- Also, if you have too much iron, our body won’t absorb as much. Just like if you are deficient in something, you will absorb more.6. How does it travel in the blood?- So now the ferrous was absorbed, so it has to be oxidized back to ferric. So AFTER it is absorbed, it has to be oxidized back to be transported. Ceruloplasmin protein will oxidize it back to ferric. The transporter protein is called apotransferrin and this is made in the liver. - Once the ferric binds to the apotransferrin, it becomes transferrin. This is normally 1/3 saturated and this is another way iron level is assessed. Because if you are deficient in iron, then the transfer protein will have less iron. Then this protein will bring it to various tissues and to the bone marrow, where RBC are made.7. Now all about the deficiency. - Deficiency is still a serious problem and results in weakness, decreases performance, inability to maintain body temperature (less oxygen), an increased lead absorption, affect pregnancy. If you know the function of iron in oxygen transport, then all o these symptoms make since.  When looking at someone’s blood when deficient, they will presents with a lower transferring saturation (remember it is normally 1/3rd saturated, but now you have less Fe) and a decrease in ferritin level (this is that storage pool of iron). They still have a normal hemoglobin amount though. The deficiency is not low enough to affect it. This is important to note!!- Once bad enough, it is termed anemia. Now the hemoglobin amount is decreasing in the body. This means without blood, so your blood has less hemoglobin and therefore less oxygen to deliver to muscles. Once the hemoglobin amount is affected, it is termed anemia. Because of Tony Berardi1the definition, anemia is not necessarily from a severe iron deficiency; it can arise from any situation that results in a loss of RBC’s.- That chart on the next slide is showing that as one crosses the line between iron deficient and anemia, their hemoglobin will fall once they are termed anemia. As you can see, the ferritin storage level decrease all the cross; but the binding capacity to transferrin increases the more deficient one gets. This is because when deficient, the body tries to increase the use of what little it has; so it will bind more readily and absorb more iron. 8. More on anemia- Now the amount of hemoglobin starts to decrease, and as a result the amount of RBC’s decrease. As a result of the lack of hemoglobin, the RBC’s will be microcytic (small)


View Full Document

FSU HUN 3226 - Metabolism 2 Exam 2

Documents in this Course
Notes

Notes

11 pages

Exam 3

Exam 3

32 pages

Cobalamin

Cobalamin

26 pages

Exam 3

Exam 3

34 pages

BONE

BONE

15 pages

BONE

BONE

24 pages

Bone

Bone

27 pages

Exam 2

Exam 2

20 pages

Exam 1

Exam 1

20 pages

Bone

Bone

7 pages

Notes

Notes

5 pages

Exam 1

Exam 1

9 pages

Thiamin

Thiamin

61 pages

Zinc

Zinc

15 pages

Exam 1

Exam 1

64 pages

Iodine

Iodine

14 pages

Test 1

Test 1

37 pages

Exam 1

Exam 1

21 pages

Exam 2

Exam 2

27 pages

Exam 2

Exam 2

16 pages

Exam 2

Exam 2

19 pages

Exam 2

Exam 2

10 pages

ZINC

ZINC

17 pages

Notes

Notes

10 pages

Exam 1

Exam 1

52 pages

Exam 1

Exam 1

40 pages

Exam 2

Exam 2

9 pages

Exam 2

Exam 2

8 pages

BONE

BONE

15 pages

Exam 1

Exam 1

22 pages

Load more
Download Metabolism 2 Exam 2
Our administrator received your request to download this document. We will send you the file to your email shortly.
Loading Unlocking...
Login

Join to view Metabolism 2 Exam 2 and access 3M+ class-specific study document.

or
We will never post anything without your permission.
Don't have an account?
Sign Up

Join to view Metabolism 2 Exam 2 2 2 and access 3M+ class-specific study document.

or

By creating an account you agree to our Privacy Policy and Terms Of Use

Already a member?