MMT: vitamins and coenzymes

Question 1

Define the term vitamin and distinguish it from other essential nutrients, such as essential fatty acids and minerals

Answer 1

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.

Question 2

name the fat soluble and water soluble vitamins

Answer 2

Water: C and B complex

Fat: A, D, E, and K

Question 3

what are the two common reaction types that b vitamin derived coenzymes are involved in

Answer 3

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

Question 4

vitamin B1: common name and active form

Answer 4

thiamine; thiamine pyrophosphate

Question 5

vitamin B1: Name the major enzymes that thiamine pyrophosphate is a cofactor for

Answer 5

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

Question 6

give the reaction with pyruvate dehydrogenase complex and name the vitamin involved in forming this enzyme

Answer 6

Pyruvate + NAD+ + CoA&raquo_space; Acetyl CoA + CO 2 + NADH

vitamin B1 (thiamine pyrophosphate)

Question 7

give the reaction with a-ketoglutarate dehydrigenase complex and name the vitamin involved in forming the enzyme

Answer 7

a-Ketoglutarate + NAD+ + CoA&raquo_space; Succinyl CoA + CO 2 + NADH

thiamine pyrophosphate

Question 8

what is associated with thiamine deficiency?

Answer 8

impaired ability to produce energy. Neuronal cells, muscle cells, CNS, cardiac cells can be impacted.

Question 9

what is beriberi disease? describe the two types.

Answer 9

dietary deficiency of thiamine; dry is involvement of CNS, wet is associated with edema and cardiomegaly

Question 10

what is wernicke korsakoff disease?

Answer 10

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

Question 11

Vitamin B2: common name

Answer 11

riboflavin

Question 12

Name the cofactors derived from vitamin B2 (riboflavin) and what they’re involved in.

Answer 12

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)

Question 13

Distinguish the structural difference between FMN and FAD.

Answer 13

FMN: riboflavin with phosphate
FAD: riboflavin with adenine and ribose

Question 14

name the reaction succinate dehydrogenase catalyzes and what vitamin it comes from

Answer 14

Succinate “ Fumarate (TCA cycle)

vitamin B2 (riboflavin)

Question 15

List some clinical manifestations associated with riboflavin (vitamin B2) deficiency.

Answer 15

• angular cheilitis (cracking around the mouth)
• Photophobia: sensitivity to sunlight
• Stomatitis: inflammation in the oral cavity
• dermatitis

Question 16

vitamin B3 common name

Answer 16

niacin

Question 17

Specify the two coenzymes derived from vitamin B3 (niacin) and compare their structural and functional properties

Answer 17

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)

Question 18

name the enzymes derived from vitamin B3

Answer 18

glyceraldehyde 3-phosphate dehydrogenase and HMG-CoA reductase

Question 19

give the reaction catalyzed by glyceraldehyde 3-phosphate dehydrogenase and the enzyme is it derived from

Answer 19

Glyceraldehyde 3-P + NAD+ + Pi&raquo_space; 1,3-bisphosphoglycerate + NADH

vitamin B3 (niacin)

Question 20

what is pellegra

Answer 20

a set of symptoms often associated with niacin (vitamin B3) deficiency; diarrhea, dermatitis, dementia

Question 21

what is Hartnup disease?

Answer 21

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.

Question 22

vitamin B5 common name

Answer 22

pantothenic acid

Question 23

Name two functional molecules derived from vitamin B5 (pantothenic acid)

Answer 23

Co-A: adenine nucleotide, ribosome, extra phosphate, business end with a thiol alcohol (high energy bond)

Phosphopantetheine: needed to create fatty acids

Question 24

name symptoms associated with vitamin B5 deficiency

Answer 24

dermatitis, enteritis, alopecia, burning neuropathy (“burning feet syndrome”), distal paresthesias, dysesthesia

Question 25

what are the three forms of vitamin B6

Answer 25

pyridoxine, pyridoxal, pyridoxamine

Question 26

name the enzymes derived from vitamin B6

Answer 26

transaminase, decarboxylase, glycogen phosphorylase, and aminolevulinic acid synthase

Question 27

name symptoms associated with vitamin B6 deficiency

Answer 27

angular chelitis, seborrheic dermatitis, conjunctivitis, sideroblastic anemia due to impact of heme synthesis

Question 28

vitamin B7 common name

Answer 28

biotin

Question 29

optic neuropathy is associated with deficiency in which B vitamin

Answer 29

B1 (thiamine)

Question 30

name the enzymes that biotin in a cofactor for

Answer 30

acetyl CoA carboxylase, propionyl CoA carboxylase, pyruvate carboxylase, methylcrotonyl CoA carboxylase

Question 31

which b vitamin can be made by intestinal bacteria

Answer 31

biotin (B7)

Question 32

give the reaction involving pyruvate carboxylase

Answer 32

Pyruvate + HCO 3- + ATP&raquo_space; Oxaloacetate + ADP + Pi

Question 33

consumption of a lot of raw egg white can lead to a deficiency in which B vitamin

Answer 33

biotin (B7)

Question 34

give some symptoms of vitamin B7 deficiency

Answer 34

alopecia, conjunctivitis, dermatitis, neurological symptoms

Question 35

name the common name for vitamin B9 and the active form

Answer 35

folic acid; THF

Question 36

what are some functions vitamin B9 is important for?

Answer 36

DNA synthesis, DNA repair, DNA methylation, his + ser + gly metabolism, methionine regeneration

Question 37

pellegra is associated with which B vitamin?

Answer 37

vitamin B3 (niacin)

Question 38

beriberi is associated with which B vitamin?

Answer 38

vitamin B1 (thiamine)

Question 39

NAD and NADP are associated with which B vitamin?

Answer 39

vitamin B3 (niacin)

Question 40

FAD and FMN are associated with which B vitamin?

Answer 40

vitamin B2 (riboflavin)

Question 41

which B vitamin is associated with carboxylases?

Answer 41

vitamin B7 (biotin)

Question 42

what are symptoms of vitamin B9 deficiency?

Answer 42

neural tube development issues, congenital malformations, megaloblastic anemia, peripheral neuropathy, cancer

Question 43

give the common name for vitamin B12

Answer 43

cobalamin

Question 44

being vegan would impact your ability to take in which B vitamin?

Answer 44

B12 (cobalamin)

Question 45

what are the active forms of vitamin B12

Answer 45

adenosylcobalamin and methylcobalamin

Question 46

which enzymes is vitamin B12 a cofactor for?

Answer 46

methylmalonyl CoA mutase and methionine synthase

Question 47

what are some symptoms of B12 deficiency

Answer 47

megaloblastic anemia, neurological disorders, pernicious anemia

Question 48

autoimmune atrophic gastritis impacts which B vitamin?

Answer 48

B12 via intrinsic factor

Question 49

tryptophan can be used to make which vitamin?

Answer 49

B3 (niacin)

Question 50

what are two coenzymes not derived from vitamins?

Answer 50

lipoamide and tetrahydrobiopterin