MMT: vitamins and coenzymes Flashcards
Define the term vitamin and distinguish it from other essential nutrients, such as essential fatty acids and minerals
vitamins are small organic molecules that can’t be used for energy directly but can be used to aid many processes in the body. they’re essential components of the diet and are a precursor for a lot of coenzymes, but are only required in small amounts.
name the fat soluble and water soluble vitamins
Water: C and B complex
Fat: A, D, E, and K
what are the two common reaction types that b vitamin derived coenzymes are involved in
Oxidation reduction: transfer of electrons. Important cofactors include FAD and NAD (riboflavin and niacin respectfully)
Activation transfer: forming covalent bonds with a substrate. Thiamine, biotin, pyridoxal phosphate, CoA
vitamin B1: common name and active form
thiamine; thiamine pyrophosphate
vitamin B1: Name the major enzymes that thiamine pyrophosphate is a cofactor for
1.Pyruvate dehydrogenase complex in glucose metabolism
2.A-ketoglutarate dehydrogenase complex in TCA cycle
3.Branched chain keto a-dehydrogenase in breaking down branched amino acids
4.Transketose in pentose phosphate pathway
give the reaction with pyruvate dehydrogenase complex and name the vitamin involved in forming this enzyme
Pyruvate + NAD+ + CoA»_space; Acetyl CoA + CO 2 + NADH
vitamin B1 (thiamine pyrophosphate)
give the reaction with a-ketoglutarate dehydrigenase complex and name the vitamin involved in forming the enzyme
a-Ketoglutarate + NAD+ + CoA»_space; Succinyl CoA + CO 2 + NADH
thiamine pyrophosphate
what is associated with thiamine deficiency?
impaired ability to produce energy. Neuronal cells, muscle cells, CNS, cardiac cells can be impacted.
what is beriberi disease? describe the two types.
dietary deficiency of thiamine; dry is involvement of CNS, wet is associated with edema and cardiomegaly
what is wernicke korsakoff disease?
progressive syndrome caused by alcoholism that impacts our vitamin supply; can damage the liver where we store vitamins, can suppress appetite keeping us from obtaining vitamins, or can damage microvilli in small intestine impacting absorption of vitamins
Vitamin B2: common name
riboflavin
Name the cofactors derived from vitamin B2 (riboflavin) and what they’re involved in.
FMN: cofactor for NADH dehydrogenase (complex I; ETC)
FAD: succinate dehydrogenase (complex II; TCA and ETC), acyl-CoA dehydrogenase (beta oxidation of fatty acids), glutathione reductase (regenerating reduced glutathione)
Distinguish the structural difference between FMN and FAD.
FMN: riboflavin with phosphate
FAD: riboflavin with adenine and ribose
name the reaction succinate dehydrogenase catalyzes and what vitamin it comes from
Succinate “ Fumarate (TCA cycle)
vitamin B2 (riboflavin)
List some clinical manifestations associated with riboflavin (vitamin B2) deficiency.
- angular cheilitis (cracking around the mouth)
- Photophobia: sensitivity to sunlight
- Stomatitis: inflammation in the oral cavity
- dermatitis
vitamin B3 common name
niacin
Specify the two coenzymes derived from vitamin B3 (niacin) and compare their structural and functional properties
NAD: nicotinamide bound to ribose, phosphate, and adenine; catabolic reactions/breaking molecules for energy
NADP: nicotinamide bound to ribose, adenine, adenine, and an extra phosphate; tends to be used as a reducing agent in its protonated form (NADPH)
name the enzymes derived from vitamin B3
glyceraldehyde 3-phosphate dehydrogenase and HMG-CoA reductase
give the reaction catalyzed by glyceraldehyde 3-phosphate dehydrogenase and the enzyme is it derived from
Glyceraldehyde 3-P + NAD+ + Pi»_space; 1,3-bisphosphoglycerate + NADH
vitamin B3 (niacin)
what is pellegra
a set of symptoms often associated with niacin (vitamin B3) deficiency; diarrhea, dermatitis, dementia
what is Hartnup disease?
mutation in tryptophan transporter that can lead to a niacin deficiency as they can’t make niacin using tryptophan. people with this are more likely to develop pellegra as they’re less capable of making niacin.
vitamin B5 common name
pantothenic acid
Name two functional molecules derived from vitamin B5 (pantothenic acid)
Co-A: adenine nucleotide, ribosome, extra phosphate, business end with a thiol alcohol (high energy bond)
Phosphopantetheine: needed to create fatty acids
name symptoms associated with vitamin B5 deficiency
dermatitis, enteritis, alopecia, burning neuropathy (“burning feet syndrome”), distal paresthesias, dysesthesia
what are the three forms of vitamin B6
pyridoxine, pyridoxal, pyridoxamine
name the enzymes derived from vitamin B6
transaminase, decarboxylase, glycogen phosphorylase, and aminolevulinic acid synthase
name symptoms associated with vitamin B6 deficiency
angular chelitis, seborrheic dermatitis, conjunctivitis, sideroblastic anemia due to impact of heme synthesis
vitamin B7 common name
biotin
optic neuropathy is associated with deficiency in which B vitamin
B1 (thiamine)
name the enzymes that biotin in a cofactor for
acetyl CoA carboxylase, propionyl CoA carboxylase, pyruvate carboxylase, methylcrotonyl CoA carboxylase
which b vitamin can be made by intestinal bacteria
biotin (B7)
give the reaction involving pyruvate carboxylase
Pyruvate + HCO 3- + ATP»_space; Oxaloacetate + ADP + Pi
consumption of a lot of raw egg white can lead to a deficiency in which B vitamin
biotin (B7)
give some symptoms of vitamin B7 deficiency
alopecia, conjunctivitis, dermatitis, neurological symptoms
name the common name for vitamin B9 and the active form
folic acid; THF
what are some functions vitamin B9 is important for?
DNA synthesis, DNA repair, DNA methylation, his + ser + gly metabolism, methionine regeneration
pellegra is associated with which B vitamin?
vitamin B3 (niacin)
beriberi is associated with which B vitamin?
vitamin B1 (thiamine)
NAD and NADP are associated with which B vitamin?
vitamin B3 (niacin)
FAD and FMN are associated with which B vitamin?
vitamin B2 (riboflavin)
which B vitamin is associated with carboxylases?
vitamin B7 (biotin)
what are symptoms of vitamin B9 deficiency?
neural tube development issues, congenital malformations, megaloblastic anemia, peripheral neuropathy, cancer
give the common name for vitamin B12
cobalamin
being vegan would impact your ability to take in which B vitamin?
B12 (cobalamin)
what are the active forms of vitamin B12
adenosylcobalamin and methylcobalamin
which enzymes is vitamin B12 a cofactor for?
methylmalonyl CoA mutase and methionine synthase
what are some symptoms of B12 deficiency
megaloblastic anemia, neurological disorders, pernicious anemia
autoimmune atrophic gastritis impacts which B vitamin?
B12 via intrinsic factor
tryptophan can be used to make which vitamin?
B3 (niacin)
what are two coenzymes not derived from vitamins?
lipoamide and tetrahydrobiopterin
