Vitamins Softchalk Flashcards
What 2 enzymes does thiamine act as cofactor for having to do with TCA cycle
pyruvate dehydrogenase
α-ketoglutarate dehydrogenase
Thiamine plays a major role in the production of
acetyl-CoA
2 diseases caused by thiamine deficiency
Beri-Beri
Wernicke Korsakoff syndrome
What enzyme does thiamine play a role in the PPP?
transketolase
What does the PPP produce that thiamine is vital for
R5P –> nucleotide synthesis
NADPH = anti-oxidant
What are the 2 co-enzymes for vitamin B2 and what type of rxns do they take part in
FAD, FMN: oxidation/reductions.
What is vitamin B2 called
riboflavin
What does B2 function as 2 parts of the oxidative phosphorylation pathway
electron carrier in the ETC and TCA cycle
What disease does B2 deficiency cause? 5 things affected by it
Ariboflavinosis - inflammation of eyes, skin (seborrheic dermatitis becoming red, scaly and greasy), lips (cheilosis), mouth, and tongue.
Coenzymes of B3 (2)
nicotinamide adenine dinucleotide (NAD) and nicotinamide adenine dinucleotide phosphate (NADP)
B3 is called
niacin
What type of rxns does B3 take part in
oxidation/reductions
What AA is B3 derived from
tryptophan
What is Hartnup’s disease a deficiency of? and how does it affect Niacin
deficiency of the neutral amino acid transporter (tryptophan) in the renal PCT. Decreased tryptophan –> decreased Niacin synthesis
What disease does Niacin deficiency cause and what are its sx? (3)
Pellagra
Dermatitis (exacerbated by sun-exposure)
Dementia
Diarrhea
What is tryptophan’s 1-letter code
W
B7 = aka?
Biotin (
Biotin is only used for what type of rxns? what do these rxns do?
carboxylation reactions - add one carbon
B5 is called
pantothenic acid (“pento”-thenic)
What is B5 a component of
Pantothenic acid is a component of Coenzyme A
What does CoA serve as? in what 2 metabolism processes
acyl carrier in fatty acid synthase and cholesterol metabolism
What 3 processes is biotin a part of
AA catabolism
FA synthase
GNG
What is B6 called? and it’s co-enzyme form that it is converted to for use in the body?
Pyroxidine: co-enzyme form is pyridoxal phosphate
What type of rxns is B6 involved in
Transamination reactions
Person has ringed sideroblasts: what is the defective enzyme, what vitamin is a cofactor, what is the disease?
B6, delta-ALA synthase
X-linked sideroblastic anemia–>defective heme synthesis
defect in methionine catabolism: what’s the disease, enzyme, and cofactor
Homocysteinuria - enzyme affected, cystathionine synthase, vitamin B6
What are the 2 substrates of ALA-synthase
glycine and succinyl-CoA.
What are the 2 enzymes in humans that use B12 as a cofactor
Methionine synthase
Methylmalony-CoA-Mutase
Methionine synthase: adds what group to what molecule to create another moilecule
CH3-B12 donates a methyl group to homocysteine to synthesize methionine (by the enzyme methionine synthase)
Methylmalony-CoA-Mutase: breaks down what 2 things into what molecule
it breaks down odd-chain FAs and BCAAs –> succinyl CoA
4 diseases that affect B12 absorption and
Pernicious anemia (AIDz –> destriuction of parietal cells
Tropical Sprue
Celiac Disease
Atropic gastritis (loss of parietal cells)
Nitrous oxide effect on B12–
Nitrous oxide inactivates B12 and can lead to symptoms of B12 deficiency.
What diabetes drug decreases uptak eof B12
metformin
WHat ABX decreases uptak eof B12
tetracycline
Vitamin C is aka?
ascorbic axcid
What type of rxn is vitamin C used in
Hydroxylation rxns
what 3 hyrdroxylation rxns is vitmain c used in
Hydroxylation of proline and lysine in collagen
Hydroxylation of dopamine to norepinephrine
Hydroxylation of hypoxia inducible factor used as an oxygen sensor in angiogenesis
vitamin A deficiency is considered a nutritionally acquired… what type of disease?
immunodeficiency disease
Which retinoid transformation plays a role in the visual cycle?
a. reduction of retinal to retinol
b. the cis/trans isomerization of a double bond
c. oxidation of retinal to retinoic acid
d. the transformation of a carotinoid to a retino
b. the cis/trans isomerization of a double bond
Chromium/ Biologically active chromomodulin has what effect in body?
enhances the effects of insulin on target tissues.
chromium deficiencies have what sx?
symptoms resemble those of diabetes mellitus
Menkes disease is caused by a deficiency of what?
a copper-transporting ATPase
Menkes disease presents as (4)
- intractable seizures
- connective tissue disorders,
- subdural hemorrhage and
- hair abnormalities (“kinky hair”)
a defect in copper excretion from the body in the bile –> copper toxicity is what disease?
Wilson’s disease
What the most common cause of preventable brain damage worldwide?
Iodine deficiency
Fluorine fucntion
hardening tooth enamel and stabilizing mineralized bone.
The molecular basis for the anemia observed in patients with copper deficiency resides in copper being an essential cofactor for
a. cytochrome C oxidase.
b. lysyl oxidase.
c. superoxide dismutase.
d. ceruloplasmin.
e. tyrosinase.
d. ceruloplasmin.
Copper is an essential cofactor for ceruloplasmin and other ferrioxidases. These ferrioxidases play an important role in iron mobilization and transport within the body. Ceruloplasmin is particularly important in loading iron onto transferrin, and so copper deficiency interferes with iron delivery to red blood cell progenitors in the bone marrow resulting in anemia.
A newborn presents with exaggerated startle reflexes and stiffness of neonatal onset. An incidental finding of hypouricemia suggested that the infant was unable to synthesize a cofactor derived from which trace mineral?
a. molybdenum
b. zince
c. iodine
d. selenium
e. manganese
e. manganese
Xanthine oxidase is involved in the catabolism of purines to uric acid. Xanthine oxidase requires the molybdenum-based cofactor Moco for activity. The neurological symptoms in this newborn are likely caused by a deficiency of sulfite oxidase, another Moco-containing enzyme.
Kashin-Beck disease is caused by the unusual susceptability of individuals with selenium deficiency to oxidative damage caused by a mycotoxin. Which enzyme requiring selenium as a cofactor provides protection against this mycotoxin in populations with sufficient selenium in the diet?
a. superoxide dismutase
b. glutathione peroxidase
c. catalase
d. phosphoenolpyruvate carboxykinase
e. tyrosinase
b. glutathione peroxidase
