Water soluble vitamins
Terms
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- What is the scientific name of vitamin B1?
- Thiamine
- What is the biologically active form of vitamin B1 and what does it do?
- Thiamine pyrophosphate (TPP), it assists in the cleavage of bonds adjacent to a carbonyl group, such as the decarboxylation of α-keto acids and in the transfer of active acetylaldehyde groups between carbon atoms.
- Which enzymes are TPP-dependent?
-
α-ketoglutarate dehydrogenase
pyruvate dehydrogenase
pyruvate decarboxylase
transketolase - What does dietary deficiency of vitamin B1 lead to and how are vitamin B1 deficiencies in general?
- Beri-beri; they are mostly neurological in nature
- What is an electron sink?
- A place for the e- to hide until they encounter their desired partner.
- What is the common name for vitamin B2?
- Riboflavin
- Riboflavin is otherwise known as ?.
- Flavin mononucleotide (FMN)
- Transfer of an adenosine monophosphate to FMN yields ?.
- Flavin adenine dinucleotide (FAD)
- What are the biologically active forms of Vitamin B2?
- flavin mononucleotide (FMN) and flavin adenine dinucleotide (FAD)
- Why are the flavins more versatile?
- Because they can accept either one or two electrons.
- In what do flavins participate in?
- Electron transfer
- In what biological process do flavins participate?
- They serve as electron carriers in oxidative phosphorylation.
- List the water-soluble vitamins.
-
-Thiamine (b1)
-Riboflavin (B2)
-Niacin
-Biotin
-Cobalamin (B12)
-Pyridoxine (B6)
-Ascorbic Acid - What are the biologically active forms of niacin?
- Nicotinamide adenine dinucleotide (NAD+) and Nicotinamide adenine dinucleotide phosphate (NADP+)
- How many electrons do NAD+ and NADP+ accept?
- 2 e-
- NAD+ is the prevalent oxidation state in what type of reactions?
- Oxidation reactions usually assoicated with catabolic processes.
- NADPH is the prevalent oxidation state in what type of reactions?
- NADPH is the major oxidation state in anabolic reactions.
- What is pellagra?
- (dermatitis, diarrhea, and dementia) caused by Niacin deficiency
- Dehydrogenases use a conserved structural motif called the ? to bind NAD or NADP.
- Rossman fold
- What is the function of biotin?
- Biotin in a coenzyme in carboxylation reactions, where it serves as a carriers of active CO2.
- What is the scientific name of vitamin B12
- Cobalamin
- What is cobalamin's function?
- Cobalamin is typically the cofactor in enzymes where a substituted alkyl group is exchanged for hydrogen on an adjacent carbon without water accessing the hydrogen atom.
- Which two enzymes require cobalamin as a cofactor?
-
methylmalonyl-CoA mutase
methionine synthase - What is required for B12 absorption through the small intestine?
- A glycoprotein called "intrinsic factor"
- Failure to produce "intrinsic factor" results in what condition?
- Pernicious anemia which results in reduced production of erythrocytes, reduced levels of hemoglobin, and severe, progressive impairment of the CNS.
- What is the common name for Pyridoxine?
- Vitamin B6
- What is the active form of vitamin B6 (pyridoxine) and what is it used for?
- Pyridoxal phosphate (PLP) is used by all aminotransferases as a prosthetic group in their reactions.
- What type of kinetics do aminotransferases exhibit? Describe.
- These enzymes exhibit ping-pong kinetics in which one substrate binds and departs, allowing the second substrate to bind and depart as the final product.
- Elevated levels of what enzyme is indicative of a heart attack?
- Eleveated levels aminotransferases are indicative of this condition.
- What is the active form of Vitamim C?
- Ascorbate
- What is the function of ascorbate?
- This vitamin is an antioxidant that keeps the non-heme iron of prolyl-4-hydroxylase in its reduced form.
- What may happen without vitamin C?
- Without this vitamin, the non-heme iron of prolyl-4 hydroxylase remains oxidized and proline hydroxylation is abolished, leading to collagen instability and connective tissue problems typical of scurvy.