Term
| What are defining characteristics of vitamins? |
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Definition
| Vital organic compounds that are not fats, carbohydrates, or proteins that cannot be synthesized in the human body |
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Term
| What are the lipid soluble vitamins? |
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Definition
|
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Term
| What are the water soluble vitamins? |
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Definition
| Vit B 1-3, 6, 12, Vit C, Folate, Panthotenic acid, Biotin |
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Term
| What are the various functions of vitamines? |
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Definition
| Metabolic coenzyme, cell & tissue integrity, hormones, essential for vision and blood coagulation |
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Term
| Where are vitamins absorbed? |
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Definition
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Term
| What enhances fat-soluble vitamin absorption |
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Definition
| Lipids, packaged in chylomicrons |
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Term
| Where are vitamins stored? |
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Definition
| Fat soluble in liver or adipose, only water soluble vitamins that can be stored are B12 and B6 |
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Term
| What is another name for Vit A? |
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Definition
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Term
| What are the 3 active forms of Vit A? |
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Definition
| Retinol, Retinal, Retinoic acid |
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Term
|
Definition
| In the liver as retinylesters |
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Term
| What are nutritional sources of Vit A? |
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Definition
| Animal liver products, as beta-carotene in dark green, leafy vegetables |
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Term
| What is the function of Vit A in vision? |
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Definition
| Retinal is part of rhodopsin in rod and cone cells |
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Term
| What is the function of Vit A in cell signaling? |
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Definition
| Retinoic acid binds to intranuclear receptors and modulates gene expression, maintenance of epithelial integrity, spermatogenesis, embryonic development |
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Term
| What is the effect of Vit A toxicity? |
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Definition
| Excessive amounts cause dry skin, mouth sores, loss of appetite, vomiting, hepatomegaly, liver failure, teratogen (birth defects) |
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Term
| What enzymes are necessary to convert beta-carotene to Vit A? |
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Definition
| Beta-carotene dioxygenase, Retinase isomerase |
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Term
| How is Vit A used in vision? |
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Definition
| Isomerization of 11-cis-retinal by light into all-trans-retinal triggers signaling through the optic nerve |
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Term
| What are the effects of Vit A deficiency? |
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Definition
| Mild = night blindness, severe = complete blindness due to keratinization of epithelial eye cells, increased infections |
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Term
| What is another name for Vit D? |
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Definition
|
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Term
| What are the functions of Vit D? |
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Definition
| Increases intestinal calcium absorption, decreases calcium excretion, mobilizes calcium from bones, maintains plasma Ca++ levels |
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Term
| What are the affects of Vit D deficiency? |
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Definition
| Pliable bones (bowed legs), rickets in children, osteomalacia in adults |
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Term
| What are the affects of excess Vit D toxicity? |
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Definition
| Loss of apetite, nausea, thirst, stupor, hypercalcinemia (deposits in kidny, arteries) |
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Term
| What is another name for Vit E? |
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Definition
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Term
| What is the function of Vit E? |
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Definition
| Primary fat soluble antioxident in the body, protects membrane lipds from free radicals |
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Term
| What are the affects of Vit E deficiency? |
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Definition
| Hemolytic anemia in premature infants, nerve damage in older children/adults due to damaged myelin |
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Term
| What process is Vit K primarily used for? |
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Definition
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Term
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Definition
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Term
| Vit K is a precursor for what? |
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Definition
| Coenzyme of glutamate carboxylation |
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Term
| What is the coenzyme for the synthesis of y-carboxyglutamate residues in proteins? |
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Definition
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Term
| What is the function of y-carboxyglutamate? |
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Definition
| Essential for Ca++ binding in osteocalcin and coagulation factor VII, IX, X, and prothrombin |
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Term
| What are the main sources of Vit K? |
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Definition
| Intestinal bacteria, leafy green vegetables |
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Term
| What are the effects of Vit K deficiency? |
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Definition
| Bleeding in newborns, bleeding in adults (if bacterial flora is killed by excessive antibiotics) |
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Term
| In what circumstances should excessive dietary intake of Vit K be avoided? |
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Definition
| During Warfarin treatment |
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Term
| What is another name for Vit B1 |
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Definition
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Term
| What is the active form of Vit B1? |
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Definition
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Term
| What is the function of Vit B1 in energy metabolism? |
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Definition
| Coenzyme in oxidative decarboxylation |
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Term
| For what TCA cycle enzymes is Vit B1 a coenzyme? |
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Definition
| Pyruvate dehydrogenase and alpha-ketoglutarate dehydrogenase |
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Term
| Vit B1 is a coenzyme for what enzyme used in the degradation of branched-chain amino acids? |
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Definition
| Alpha-ketoacid dehydrogenase |
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Term
| What is the function of Vit B1 in pentose phosphate pathway? |
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Definition
| Coenzyme for transketolase |
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Term
| How is thiamine deficiency assayed? |
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Definition
| Through RBC transketolase activity |
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Term
| What are the results of Vit B1 deficiency? |
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Definition
| TCA cycle impairment leads to various neurological symptoms |
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Term
|
Definition
| Severe thiamine deficiency |
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Term
| What are the symptoms of Beriberi? |
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Definition
| Infant: tachycardia, vomiting, convulsions, Adult: dry skin, irritability, disorderly thinking, progressive paralysis |
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Term
| What is Wernicke-Korsakoff syndrome? |
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Definition
| Chronic alcoholism induced Vit B1 deficiency, alcohol impairs thiamine absorption |
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Term
| What are Wernicke-Korsakoff syndrome symptoms? |
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Definition
| Apathy, loss of memory, confusion, inability to move eyes |
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Term
| What is another name for Vit B2? |
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Definition
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Term
| What is the function of Vit B2 (Riboflavin) |
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Definition
| Coenzyme in the forms of flavin mononucleotide (FMN) and flavin adenine dinucleotide (FAD) |
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Term
| What are the affects of Vit B2 deficiency? |
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Definition
| Deficiency is rare, results in cracked lip corners (cheliosis), dermatitis, purple smooth tongue (glossitis) |
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Term
| What is another name for Vit B3? |
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Definition
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Term
| What is the function of Vit B3 (niacin)? |
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Definition
| NAD and NADPH precursor (can be substituted by Trytophan) |
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Term
| What is the result of Vit B3 (niacin) deficiency? |
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Definition
|
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Term
| What are the symptoms of Pellagra (niacin deficiency) |
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Definition
| DDDD = Dermatitis, Diarrhea, Dementia, Death (if untreated) |
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Term
| Excess Vit B3 (niacin) toxicity manifests as what symptoms? |
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Definition
| Skin flushing, itching, tingling, burning sensation on skin |
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Term
| How is Vit B3 (niacin) used as a drug? |
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Definition
| High cholesterol treatment to reduce lipolysis in adipose, reduce triglyceride, VLDL, and LDL levels |
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Term
| What is another name for Vit B6? |
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Definition
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Term
| What is the active form of Vit B6 (pyridoxine) |
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Definition
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Term
| What is the function of Vit B6 (pyridoxine)? |
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Definition
| Coenzyme in transamination, certain deamination, and certain carboxylation reactions (dopamine, histamine, serotonin synthesis), heme synthesis |
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Term
| What is the affect of Vit B6 (pyridoxine) deficiency? |
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Definition
| Rare deficiency results in hyperirritability, neuritis, convulsions |
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Term
| What is the result of Vit B6 (pyridoxine) toxicity? |
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Definition
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Term
| What is another name for Vit C? |
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Definition
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Term
| What is the function of Vit C (ascorbic acid)? |
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Definition
| Collagen synthesis, neurotransmitter synthesis, tyrosine degradation, antioxidant |
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Term
| What is the result of Vit C (ascorbic acid) deficiency? |
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Definition
| Bleeding, bruising, delayed wound healing, loose teeth, extreme cases lead to scruvy |
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Term
| What is the result of Vit C (ascorbic acid) toxicity? |
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Definition
| Intestinal problems, diarrhea |
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Term
| What is the function of Panthotenic acid? |
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Definition
| Precursor of CoA (used in heme, sphingolipid, cholesterol, heme, neurotransmitter, energy production) |
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Term
| What is the result of Panthotenic acid toxicity or deficiency? |
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Definition
|
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Term
| What is the function of Biotin? |
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Definition
| Coenzyme in carboxylation reactions (FA synthesis, gluconeogenesis, leucine degradation, propionyl CoA degradation) |
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Term
| What are common sources of biotin? |
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Definition
| Corn, soy, low amounts in wheat |
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Term
| What is the result of biotin deficiency or toxicity? |
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Definition
| Rare (avidin, an egg white protein binds biotin strongly), never toxic |
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Term
| Trace elements of what minerals are essential? |
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Definition
| Iron, copper, zinc, iodine, selenium |
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Term
| What non-heme proteins require iron? |
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Definition
| Iron-sulfur clusters (e.g. ferredoxins) |
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Term
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Definition
| Iron transporters reside in lumenal and basal sides of intestinal epithelial cells |
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Term
| What regulates absorption of iron? |
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Definition
| Hepicidin (liver hormone) |
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Term
|
Definition
| As ferritin, primarily in the liver in Fe3+ form |
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Term
| What converts Fe2+ to Fe3+? |
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Definition
|
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Term
|
Definition
| Transferrin (Fe3+) and Albumin (Fe2+) |
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Term
| What is the copper membrane transporter? |
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Definition
|
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Term
| What is the intracellular copper transporter (chaperon)? |
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Definition
|
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Term
| What and where are the ATP dependent copper pumps? |
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Definition
| ATP7A (intestines) ATP7B (liver) |
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Term
| What is deficient in Menke's disease? |
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Definition
| Intestinal copper transporter ATP7A (poor uptake) |
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Term
| What are the main symptoms of Menke's disease? |
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Definition
| Neurological effects, growth retardation, hypopigmentation, laxity of skin |
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Term
| How is Menke's disease treated? |
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Definition
|
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Term
| What is deficient in Wilsons' disease? |
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Definition
| ATP7B transporter in the liver (deficient excretion) |
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Term
| What are the symptoms of Wilson's disease? |
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Definition
| Cirrhosis, liver failure, neurological defects, psychiatric symptoms |
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Term
| How is Wilson's disease treated? |
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Definition
| Copper-restricted diet, copper chelators, oral zinc tablets |
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Term
| What important copper-dependent enzymes should be remembered? |
|
Definition
| Ceruloplasmin, Cytochrome C oxidase, Dopamine beta-hydroxylase, Lysyl oxidase, Tyrosinase |
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Term
| What is the function of Cytochrome C oxidase? |
|
Definition
| Mitochondrial respiration |
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Term
| What is the function of Dopamine beta-hydroxylase? |
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Definition
|
|
Term
| What is the function of lysyl oxidase? |
|
Definition
| connective tissue formation |
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Term
| What is the function of tyrosinase? |
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Definition
|
|
Term
| Zinc is an essential function for what processes? |
|
Definition
| Oxidative phosphorylation, protection against oxidative stress, acid-base balance, protein degradation, transcription |
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Term
| What physiological role does zinc play? |
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Definition
| Wound healing, skin integrity, spermatogenesis, pancreatic function |
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Term
|
Definition
| In metallothioneine (also binds copper with even higher affinity) |
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Term
| What are the affects of zinc deficiency? |
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Definition
| Acrodermatitis enteropathica (deficient zinc transporter), leads to red and inflamed patches of dry scaly skin, progresses to blistered leasions, hair loss, diarrhea |
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Term
| Iodine is important for what functions? |
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Definition
| Thyroid hormone synthesis |
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Term
| What are the affects of iodine deficiencies? |
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Definition
| Goiter (enlarged thyroid), Cretinism in children (mother had limited iodine intake during pregnancy, mental and growth retardation in child) |
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Term
| What are the main forms of selenium in the body? |
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Definition
| Selenocysteine and selenomethionine |
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Term
| What is the 21st proteinogenic amino acid? |
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Definition
| Selenocysteine, indirectly coded by the genetic code |
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Term
| What enzymes contain selenium? |
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Definition
| Glutathione peroxidase (antioxidant), thioredoxin reductase (antioxidant), thyroid hormone deiodinase (converts T4 to T3) |
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Term
| What causes Keshan disease and what are its symptoms? |
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Definition
| Selenium deficiency, manifests as cardiomyopathy |
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Term
| What are the results of excess selenium? |
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Definition
| Selenium toxicity causes brittle nails and hair, intestinal problems, garlic-like body odor, neurological problems |
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