Vitamins and Cofactors Flashcards
Oxygenase and dehydrogenase are a ______ class of enzyme. Kinases, acyltransferase, and acetyltransferase are all _____ class of enzymes.
Oxidoreductase
Transferase
_____ reactions function in the body for fuel oxidation, detoxification, and biosynthesis
Redox
Redox cofactors include _____, ____ , ____, ____, ______
NADH, NADPH, FAD(2H), ascorbic acid, and metals such as copper, iron.
What is this cofactor:
Nicotinamide adenine dinucleotide (NAD+) . The pink hydrogen at the top shows the active side and where the reduction takes place to for NADH
An example of a redox reaction is lactate to pyruvate, where ____ is the cofactor.
NAD+
A reaction usually uses only ____ or ___, not both. ____ is primarily used in fuel oxidation. ____ is used in detoxification and biosynthesis.
NADH or NADPH
NADH
NADPH
The dietary precursor for NADH and NADPH is ______. It is abundant in meat, whole grains, and fortified cereals.
Niacin (vitamin B3)
Niacin can by synthesized in the body from _____, which we also get from our diet. This requires vitamin ____.
Tryptophan
Vitamin B6
Deficiency of niacin causes ______, characterized by dermatitis, diarrhea, and dementia (3Ds).
Pellagra
____ and ____ are also redox cofactors but they accept 1 electron at a time. They also participate in creating and breaking ____ bonds and ____ bonds.
FMN and FAD
Double
Disulfide
FMN stands for ____ ____. FAD stands for _____ ____ ____. They are similar but FAD has an added adenosine that acts as a _____ where enzymes grab on to.
Flavin mononucleotide
Flavin adenine dinucleotide
Handle
FAD and FMN are derived from ______.
Riboflavin (vitamin B2)
Succinate dehydrogenase uses ______ as a redox cofactor.
FAD
Riboflavin (vitamin B2) comes from ___, ____, _____, ____, and _____ in our diet
Milk, eggs, organ meat, legumes, and mushrooms
Riboflavin is phosphorylated by ______ using ATP to create ______. Then an adenine is added by enzyme _____ to form FAD.
Flavokinase
FMN
FAD synthetase
Riboflavin deficiency results in _____ and ____, which are sores around the mouth and a beefy swollen tongue, respectively. Anemia, dermatitis, GI malabsorption, or mutations in succinate dehydrogenase can also occur.
Cheilosis
Glossitis
______ is a redox cofactor for hydroxylase enzymes important in collagen synthesis, neurotransmitter synthesis, and oxygen sensing. It also functions as a ______ anti-oxidant
Ascorbic acid (vitamin C)
Non-enzymatic
Hydroxylase enzymes add and ___ group which allows for hydrogen bonding in collagen. If ____ is deficient, hydroxylase is unable to function properly leading to weak collagen.
OH
Ascorbic acid (vitamin C)
Vitamin C (ascorbate) is a cofactor for ____ hydroxylase. Post translational hydroxylase of ____ and ____ is important for collagen formation.
Prolyl
Lysine
Proline
____ hydroxylase adds a OH group to lysine
Lysyl
Collagen is important for extracellular connective tissue. In the collagen peptide, every third amino acid is ____. Collagen peptides form a ___ ___ structure that is stabilized by hydrogen bonding.
Glycine
Triple helix
Ascorbic acid (vitamin C) is found in ____ and ____ in our diet.
Citrus
Vegetables
____ is an ascorbic acid deficiency characterized by defects in connective tissue, bleeding, slow wound healing, anemia, gingival lesions (gum lesion), enlargement of costochondral junctions, and Pertichia (bleeding capillaries)
Scurvy
Diagnose scurvy by clinical presentation, _____ findings, and _____ clearance after oral ascorbate bolus.
Radiologic
Urinary
_____ is important for iron absorption.
Ascorbic acid (vitamin C)
_____ ____ is an activation transfer cofactor. It participates in decarboxylation reactions. After decarboxylation of pyruvate the remaining two carbons form a ____ bond with TPP.
Thiamine pyrophosphate (TPP)
Covalent
Thiamine is found in ____, _____, _____, and _____ in our diet.
Meat, legumes, whole grains, fortified cereals
Thiamine deficiency can occur in _____ and _____. _____ is characterized by headache, nausea, malaise, heart failure. _____ _____ is characterized by confusion and abnormal eye movements. ____ ____ is characterized by amnesia and confabulation.
Malnutrition
Alcoholism
Beriberi
Wernicke encephalopathy
Koraskoff psychosis
____ ____ ____ ____ syndrome is due to inherited mutations in the thiamine transporter SLC19A2. Characterized by anemia, progressive deafness, and non type I diabetes
Thiamine responsive megaloblastic anemia
_____ is an activation transfer cofactor that forms a covalent bond with lysine side chains.
Lipoate
Lipoate is a cofactor for the E2 subunit of _____ _____. It accepts the two carbon acetate from TPP. Lipoate has ____ transfer function and ______ function
Pyruvate dehydrogenase
Carbon
Oxidation reduction
_____ does not require a vitamin precursor. _____ and _____ synthesis lipoid acid. Deficiency is not fully described
Lipoate
Fatty acids
Amino acids
_____ is an activation transfer cofactor. It functions to covalently bind _____ groups through high energy thioester bonds, and transfer them to different substrates
Coenzyme A (CoASH or CoA)
Acyl
The dietary precursor for coenzymeA is _______. It is widespread in the diet and specific deficiency is not described
Pantothenic acid (vitamin B5)
____ is a activation transfer coenzyme. It is a cofactor for four carboxylase enzymes.
Biotin
_____ reactions are the formation of new carbon-carbon bonds from inorganic carbon
Carboxylation
_____ is widely distributed in food and deficiencies are rare. Raw eggs contain _____ which binds to biotin and makes in indigestible. Symptoms include scaley dermatitis, thinning hair, and alopecia
Biotin
Avidin
____ ____ is an activation transfer cofactor for enzymes that metabolize amino acids.
Pyridoxal phosphate (PLP)
____ is a type of enzyme that uses PLP as a cofactor to metabolize amino acids
Transaminases
_____ is the precursor for pyridoxal phosphate.
Vitamin B6
3 types of vitamin B6 are ___ , ___, ____. They are found in the diet in meat, bananas, rice. They must be _____ by kinase to convert them to _____.
Pyridoxine
Pyridoxal
Pyridoxamine
Pyridoxal phosphate
Pyridoxal deficiency is characterized by ____, ____, and anemia in infants and _____ ____ in adults.
Seizures, diarrhea
Peripheral neuropathy
PLP is a cofactor in the pathway that converts tryptophan to ____. PLP deficiency can cause a ____ deficiency.
Niacin
Niacin
Direct measurement of ___ in blood is a diagnostic tool to measure PLP deficiency.
PLP
PLP overdose causes _____ and ____.
Sensory neuropathy and ataxia
_____ is an activation transfer cofactor that participates in transfers and rearrangements of methyl groups
Cobalamin (vitamin B12)
The two forms of cobalamin in the body are ____ and ____.
Deoxyadenosylcobalamin
Methylcobalamin
Methylcobalamin is a cofactor for ______ synthase. After transferring its ____ group, Methylcobalamin is regenerated by accepting a ____ group from methyltetrahydrofolate. Methionine is important for protein synthesis.
Methionine
Methyl
Methyl
Adenosylcobalamin is a cofactor for ______ _____ _____, which is essential for the catabolism of branched chain amino acids and fatty acids
Methylmalonyl CoA mutase
____ is only produced by bacteria, it is found in meat, milk, and other animal derived foods. Deficiency can occur in vegans and causes _____, ____, ____, ____, and _____.
Cobalamin
Anemia, weakness, fatigue, seizures, and sensory defects
Diagnosis of cobalamin deficiency by ___ ___ and testing the cobalamin concentration in serum.
Blood smear
What vitamin derived cofactors are required for different aspects of fuel oxidation?
Which type of enzyme uses biotin as a cofactor?
Carboxylase
Carboxylase
White cell acetyl CoA carboxylase assay
Lack of dietary vitamin B12
Cyanocobalamin
(Vitamin B12)
Methionine cycle
