Reading...
Play button
Play button
Use LEFT and RIGHT arrow keys to navigate between flashcards;
Use UP and DOWN arrow keys to flip the card;
H to show hint;
A reads text to speech;
55 Cards in this Set
- Front
- Back
|
What is the function of folic acid?
|
1. Enzyme cofactor (tetrahydrofolate)
2. 1 Carbon transfer in synthesis of amino acids 3. Prevents neural tube defects |
|
|
What happens when there is a deficiency of folic acid?
|
- Megobalstic anemia
- Neural tube deffects |
|
|
What is megoblastic anemia?
|
A nutritional form of anemia, in which there is a decrease in nucleic acid synthesis, which affects rapidly dividing cells (bone marrow & gut).
Large, immature RBC precursors accumulate. |
|
|
What is the cause of folic acid deficiency?
|
- increase demand (pregnancy/lactation)
- decreased dietary intake - alcoholism - poor absorption - dihydrofolate inhibitors (methotextrate) |
|
|
What is the function of B12?
|
An enzyme cofactor for:
1. Methylmalonyl CoA Mutase (breaks down fatty acid bonds) 2. Homocysteine methyltransferase (methionine synthesis) |
|
|
What can happen with a deficiency of B12?
|
- Accumulation of odd # of fatty acids, which may enter cell membranes of nerves
- Neurological abnormalities and degeneration of the spinal cord - Glossitis, diarrhea and weight loss - Secondary folate defficiency, may cause megoblastic anemia |
|
|
What can cause a deficiency of B12?
|
- decreased intake (vegans!)
- disease of the ileum (e.g. Crohns or not enough IF in SI) - surgical recession of gut - prenicious anemia (autoimmune disease may kill the IF) - pancreatic insufficiency (can't digest protein bound B12) |
|
|
What is the function of vitamin C?
|
- coenzyme in hydroxl reactions (collagen/adrenaline)
- maintaining connective tissue - wound healing - reducing agent - absorption of iron - antioxidant/free radical scavenger |
|
|
What can happen with a deficiency of vitamin C?
|
Scurvy
symptoms due to decreased collagen synthesis and include anemia, bruising, poor wound healing, swollen joints and muscle pain. |
|
|
What is the cause of a vitamin C deficiency?
|
- Not eating enough fruits and veggies
- often occurs in elderly or alcoholics |
|
|
What is the function of vitamin B6?
|
- Enzyme cofactor (active form is PLP)
- Required for glycogen phosphorylase - Required for amino acid metabolism - Required to convert tryptophan to niacin |
|
|
What is caused by a deficiency in vitamin B6?
|
- Abnormal amino acid metabolism
- Secondary Pellagra (b/c not enough Niacin [B3]) - Microcytic anemia |
|
|
What causes a deficiency in vitamin B6?
|
- Primary form is quite rare
- Women on birth control pills - Alcoholics, elderly - isoniazide (for TB) inactivates PLP and can cause B6 deficiency |
|
|
What is the function of vitamin B1 (thiamine)?
|
Cofactor for enzymes (TPP):
1. PDH complex 2. alpha-ketoglutarate dehydrogenase 3. Transketolase 4. Branched chain amino acids, alpha ketoacid dehydrogenase |
|
|
What is caused by a deficiency in vitamin B1?
|
- Decreased ATP production (effects CNS)
- Accumulation of lactate and pyruvate (lactic acidosis) - Decreased NADH formation via HMP affects fatty acid synthesis - BERI BERI - WERNICKE'S ENCEPHALOPATHY - KORSAKOFF'S SYNDROME |
|
|
What are the symptoms and causes of Berri Berri?
|
Caused by deficiency of vitamin B1
dry skin, irritability, progressive paralysis |
|
|
What is the cause and symptoms of Wernicke's encephalopathy?
|
Caused by deficiency of vitamin B1
confusion, atoxia, eye paralysis, neuropathy, nystagmus |
|
|
What is the cause and symptoms of Korsakoff's psychosis?
|
caused by deficiency of vitamin B1
irreversible syndrome, causing amnesia, deficits in learning and memory |
|
|
What are the causes of Vitamin B1 deficiency?
|
alcohlism
system diseases (cancer, AIDS) insufficient dietary intake severe liver disease |
|
|
What is the function of Vitamin B3?
|
- cofactor for oxidase and deyhdrogenase enzymes
- repair of UV light damage in skin - Treatment of hyperlipidemia in high doses |
|
|
What is caused by a deficiency in vitamin B3?
|
Pellagra
-photosensitive dermatitis -diarrhea -dementia -can lead to death |
|
|
What causes a deficiency in Vitamin B3?
|
-decreased dietary intake
-protein deficiency (inadequate intake of trp) -Vitamin B6 & PLP -Harnup's disease |
|
|
What is the function of Vitamin B2?
|
cofactors for oxidase and dheydrogenase enzymes
active forms are FAD & FMN |
|
|
What is the function of biotin?
|
coenzyme for carboxylation reactions
1. Pyruvate carboxylase 2. Acetyl CoA carboxylase 3. Propionyl CoA Carboxylase 4. Branched-chain amino acid metabolism |
|
|
What may a biotin deficiency cause?
|
dermatitis
|
|
|
What are possible causes of biotin deficiency?
|
consuming large amount of egg whites, long-term antibiotic therapy
|
|
|
What is the function of pantothenic acid?
|
Transfer of acyl groups as component of CoA
Component of fatty acid synthase |
|
|
What may a deficiency of pantothenic acid cause?
|
burning foot syndrome
|
|
|
What are the 9 water soluble vitamins?
|
B6
B1 (Thiamine) B2 (Riboflavin) B3 (Niacin) Biotin Pantothenic acid Folic acid B 12 Vitamin C |
|
|
What are the fat soluble vitamins?
|
K
A D E |
|
|
What is the function of Vitamin A?
|
Retinoic Acid: steroid hormone important for epithelial development
Retinal: Vision Retinol: Reproduction and fertility Beta-carotene: Antioxidant Growth of bones and teeth |
|
|
What is the cause of Vitamin A deficiency?
|
inadequate dietary intake or secondary to fat malabsorption
|
|
|
What does a deficiency in Vitamin A cause?
|
Eyes:
- Night blindness - increased keratonization of cornea, leading to cataracts Skin: impaired mucosal functiona, thick/dry skin |
|
|
What does too much Vitamin A cause?
|
dry itchy skin and dermatitis
hepatomegaly thinning/fracturing of long bones mucous membrane defects/hair loss rise in intracranial pressure causes birth defects during pregnancy (teratogen) |
|
|
What is the function of Vitamin K?
|
-Coenzyme for carboxylation of glutumate residues of clotting factors II, VII, IX, X and prothrombin. Activates clotting cascade
|
|
|
What causes a deficiency in Vitamin K?
|
Decreased bacteria in the gut
Inadequate dietary intake Newborns can't synthesize it right away b/c they are born with a sterile gut |
|
|
What happens with a deficiency of Vitamin K?
|
Poor clotting and bleeding disorders
Hemorrhagic diesease in newborns |
|
|
What is caused by toxicity of Vitamin K? (in infants)
|
hemolytic anemia and jaundice
|
|
|
What is the most active form of Vitamin E?
|
alpha-tocopherol
|
|
|
What is the function of Vitamin E?
|
- antixodant
- may protect against heart disease |
|
|
What are the causes of a Vitamin E deficiency?
|
Severe fat malabsorption
In premature infants |
|
|
What are happens when there is a deficiency of Vitamin E?
|
-Can cause hemolytic anemia in new borns (b/c increased oxidative stress on RBCs)
In children and adults: - muscle weakness - ataxia - peripheral neuropathy - nystagmus |
|
|
What is the function of Iodine?
|
Oxygen transport (component of heme and myoglobin)
Component of iron containing enzymes: cytochrome P9450 Iron sulfer centers (ETC Catalase |
|
|
What is the function of Zinc?
|
Cofactor for enzymes and part of Zinc fingers for DNA binding domains in certain transcription factors
|
|
|
What is the function of Copper?
|
Cofactor for enzymes
|
|
|
What is the function of Iodine?
|
Required to make thyroid hormones
|
|
|
What is the transport process of iron?
|
Iron absorption is facilitated by vitamin C and transported into blood by Transferrin to its site of storage
|
|
|
Where and how is iron stored in the body?
|
Iron is stored in bone marrow (hemoglobin synthesis)
Liver (enzyme synthesis) Muscles (myoglobin synthesis) It is mostly stored as FERRITIN and some also as HEMOSDERIN |
|
|
What is the cause of iron deficiency?
|
increased requirements (pregnancy or growth)
inadequate dietary intake blood loss malabsorption |
|
|
What is the effect of iron deficiency?
|
anemia: decreased hemoglobin, decreased oxygen reaching tissues causing pallor, SOB, tiredness and palpations
Epithelial abnormalities: angular stomattis, glossitis |
|
|
What are the effects of zinc deficiency?
|
Ancrodermaticis enceropathica, causes malabsorption in the small intestine
causes: slowed growth, hypogonadism, delayed wound healing |
|
|
What is the cause for copper deficiency?
|
Menke's Kinkey Hair syndrome, which presents with:
depigmentation of the hair arterial degeneration neuronal degernaration mental retardation growth failure anemia |
|
|
What are the effects of copper deficiency?
|
weak walled blood vessels
failure of pigementation neurological effects tissue damage iron deficiency anemia |
|
|
What are happens when there is an overload of copper?
|
Wilson's Disease
liver does not excrete copper in bile, so it accumulates causing copper to deposit in: liver brain eyes |
|
|
What are the effects of iodine deficiency?
|
Goiter, enlarged thyroid due to an increase in thyroid stimulating hormone (TSH)
deficiency during pregnancy may cause hypothyroidism in newborn, imparining growth and mental development (Cretinism) |
