Term
True or False
The majority of calcium ingested, passes through the GIT unabsorbed |
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Definition
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Term
True or False
Calcium diffuses readily down its concentration gradient |
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Definition
| false, its not very good at it |
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Term
| Absorption of calcium via diffusion is (independent/dependent) on calcium |
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Definition
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Term
| Vitamin D dependent absorption of calcium occurs in the... |
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Definition
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Term
| What carrier molecule binds to calcium for transport via active pumping? |
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Definition
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Term
True or False
Phosphorous diffuses readily down its concentration gradient |
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Definition
| true (but it's absorbed in phosphate form) |
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Term
| How does Vit D influence phosphate absorption? |
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Definition
| low-P diet will cause vit D to promote absorption by increasing expression of Na/PO4 symporters |
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Term
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Definition
-via receptors for protein-bound iron (e.g. heme, lactoferrin)
-via DMT-1 transporter (Fe/H+ symporter) |
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Term
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Definition
| storage site for iron as Fe3+, will release it into blood as needed |
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Term
| Iron is transported through the blood via... |
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Definition
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Term
True or False
There is no specific mechanism for
iron excretion |
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Definition
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Term
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Definition
| secreted by liver when iron stores are high, it reduces iron absorption in the gut |
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Term
| What do you measure to estimate iron levels in the body? |
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Definition
| transferrin levels in plasma |
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Term
| When is Vit C required for iron absorption? |
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Definition
when it is bound to ferritin or hemochrome (eggs and veggies)
NOT required for heme-bound iron (meat) |
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Term
| Why is it important to balance Cu & Zn in the diet? |
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Definition
| they compete for the same carrier |
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Term
| Fat soluble vitamins are absorbed via (active/passive) diffusion |
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Definition
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Term
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Definition
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Term
| Vit B6 is absorbed via... |
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Definition
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Term
| Vit B12 is absorbed via... |
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Definition
| binding of B12 to intrinsic factor, then binding to ileal enterocytes |
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Term
| Vit B12 binds to intrinsic factor in the.... |
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Definition
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Term
| B12/intrinsic factor complex is is absorbed in the... |
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Definition
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Term
| Why might exocrine pancreatic insufficiency lead to a B12 deficiency? |
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Definition
| pancreas produces intrinsic factor which is required for B12 absorption (applies to carnivores only - herbivore bacteria produce their own) |
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