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26 Cards in this Set
- Front
- Back
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Two parts to riboflavin structure |
Flavin and Ribitol (sugar alcohol) |
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RDA for Riboflavin |
M- 1.3mg/day F- 1.1mg/day |
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Three forms of Riboflavin |
Free form, FMN (Flavin mononucleotide) FAD (Flavin Adenine Dinucleotide) |
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FAD = _____ + _____ |
FMN + AMP |
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Enzymes involved in Riboflavin to FAD |
Flavokinase FAD Synthase |
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Riboflavin is only absorbed in ____ form in ____ and _____ |
Free Duodenum Jejunum |
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True or False: Digestion is needed for absorption of Riboflavin |
True |
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FAD ----> FMN ----> Riboflavin enzymes |
FAD Pyrophosphatase, FMN Phosphatase |
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Riboflavin transport features |
Energy-dependent Sodium-independent carrier mediated Riboflavin transporters RFTs/RFVTs |
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Found in the basolateral membrane of enterocytes |
RFVT1 |
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Found in intracellular vesicles and basolateral membrane. Ubiquitously expressed -all tissues |
RFVT2 |
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Main transporter found in apical membrane of enterocytes |
RFVT3 |
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Group of membrane proteins include over 300 members organized in 52 families Transport variety of substrates including glucose, minerals, AA etc. |
Solute Carrier |
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Riboflavin transport is mediated by |
Facilitated diffusion |
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RF, FMN, and FAD are bound to proteins like albumin, only free RF enters cells. In blood or tissues? |
Blood |
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RF rich in liver, kidney, heart. Converted to FMN and FAD inside cells (trapped). FMN major form (60-95%). In blood or tissues? |
Tissue |
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FMN and FAD form part of enzymes called ___ that are involved in redox reactions |
Flavoproteins |
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FMD and FAD are ____ agents and accept e- and protons |
Oxidizing |
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FMN/FAD = _____ form FMNH2 or FADH2 ____ form |
Oxidized Reduced |
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Measure of tendency of molecule to accept e- and thereby be reduced |
Redox potential |
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FADH2 enters the ETC at complex ___ NADH enters the ETC at complex ___ |
2 1 |
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One molecule of FADH2 generates ___ ATP |
2 |
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Catalyzes the transfer of e- from NADH to coenzyme Q10. Generates 4H+ for each NADH. What form of RF is required? |
Complex I, FMN |
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Deficiency of RF is known as |
Ariboflavinosis |
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Symptoms of Ariboflavinosis |
Inflammation of tongue, can inhibit syn. of niacin and B6 metab. |
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Rare neurological genetic disorder of mutation of rf transporter |
Brown-Vialetto-Van Laere syndrome |
