Usmle Biochem Nutrition

Front 1

Vitamins A D E K, what types of vitamins are these and what are they dependent upon to be absorbed?

Back 1

Fat soluble vitamins absorbed in ileum and dependent on the pancreas

Front 2

What malabsorbtion syndromes cause problems with fat soluble vitamins?

Back 2

Steatorrhea
Cystic fibrosis and sprue
Mineral oil intake

Front 3

B1, B2, B3, B5, B6, B12 C and Biotin and Folate. What types of viatamins are these?

Back 3

Water soluble

Front 4

Which two water soluble vitamins not wash out and where are they stored?

Back 4

B12 and folate, stored in liver

Front 5

Dermatitis, glossitis and diarrhea.

Back 5

B-complex defficiencies

Front 6

An antioxidant essential for normal differentiation of epithelial cells into specialized tissue (pancreatic cells, mucus secreting cells) Constituent of visual pigments

Back 6

Vitamin A retinol

Front 7

Deficiency causes night blindness and dry skin

Back 7

Vitamin A retinol

Front 8

Excess causes arthralgias, fatigue, headaches, skin changes, sore throat, alopecia. Teratogenic (cleft palate, cardiac abnormalities) so preganancy test must be done before isotretinoin is prescribed for severe acne.

Back 8

Vitamin A retinol

Front 9

Found in liver and leafy vegetables. Deficiency causes night blindness.

Back 9

Vitamin A retinol

Front 10

Retinol

Back 10

Vitamin A retinol

Front 11

Thiamine

Back 11

Vit B1

Front 12

A cofactor for several enzymes
1. Pyruvate dehydrogenase (glycolysis)
2. alpha-ketoglutarate dehydrogenase (TCA cycle)
3. Transketolase (HMP shunt)
4. Branched-chain AA dehydrogenase

Back 12

Vit B1 (Thiamine)

Front 13

Deficiency causes impaired glucose breakdown causing ATP depletion; highly aerobic tissues (brain and heart) are affected first. Wernicke-Karsakoff syndrome and beriberi, Seen in malnutrition as well as alcoholism (secondary to malnutrition and malabsorption)

Back 13

Vit B1 (Thiamine)

Front 14

Confusion, opthalmoplegia, ataxia + memory loss, confabulation, personality change. What is this and what vitamin is it related to?

Back 14

Wernicke-Korsakoff syndrome in Vit B1 (Thiamine) deficiency

Front 15

Polyneuritis, symmetrical muscle wasting. What is this and what vitamin is it related to?

Back 15

Dry beriberi, due to a Vit B1 (Thiamine) deficiency

Front 16

High-output cardiac failure (dilated cardiomyopathy), edema. What is this and what vitamin is it related to?

Back 16

Wet beriberi, due to a Vit B1 (Thiamine) deficiency

Front 17

Riboflavin

Back 17

Vitamin B2 (Riboflavin)

Front 18

Functions as a cofactor in oxidation and reduction (e.g, FADH2)

Back 18

Vitamin B2 (Riboflavin)

Front 19

Deficiency causes cheilosis (inflammation of lips, scaling and fissures at the corners of the mouth) and Corneal vasculirization

Back 19

Vitamin B2 (Riboflavin)

Front 20

Niacin

Back 20

Vitamin B3 (Niacin)

Front 21

Constituent of NAD+ and NADP+ (redox rxns) Derived from tryptophan, synthesis requires vitamin B6

Back 21

Vitamin B3 (Niacin)

Front 22

Deficiency causes glossitis. Sever deficiency leads to pellagra, which may be caused by Hartnup disease (dec tryptophan absorption), malignant carcinoid syndrome (increase in tryptophan metabolism) and INH (dec. vit B6)

Back 22

Vitamin B3 (Niacin)

Front 23

Excess causes facial flushing (due to pharmacologic doeses for trx of hyperlipidemia)

Back 23

Vitamin B3 (Niacin)

Front 24

What are the three D's of pellegra, what vit def is this found in?

Back 24

Vitamin B3 (Niacin) diarrhea, dermatitis, dementia

Front 25

What dietary cause can cause pellegra?

Back 25

Vitamin B3 (Niacin) in corn not absorbable unless treated, excess untreated corn in diet can lead to pellagra.

Front 26

Pantothenate

Back 26

Vitamin B5 (Pantothenate)

Front 27

Essential component of CoA (a cofactor for acyl trasfers) and fatty acid synthase.

Back 27

Vitamin B5 (pantothenate)

Front 28

Deficiency causes dermatitis, enteritis, alopecia and adrenal insufficiency

Back 28

Vitamin B5 (pantothenate)

Front 29

Pyridoxine

Back 29

Vitamin B6 (Pyridoxine)

Front 30

Converted to its phosphate version (called) is a cofactor used in transamination (e.g ALT and AST), decarboxylation rxns, glycogen phophorylase, cystathionine synthesis and heme synthesis, Required for the synthesis of niacin from tryptophan

Back 30

Vit B6 Pyridoxine in pyridoxal phosphate

Front 31

Deficiency causes convulsions, hyperirritability, peripheral neuropathy (deficiency inducible by INH and oral contraceptives) and sidereblastic anemias.

Back 31

Vit B6 Pyridoxine

Front 32

Cobalamin

Back 32

Vitamin B12 (cobalamin)

Front 33

Cofactor for homocysteine methyltransferase (transfers CH3 groups as methylcobalamin) and methylmalonyl- CoA mutase
Homocysteine + N- Methyl THF -?-> Methionine + THF
Methylmalonyl-CoA -?-> Succinyl-CoA

Back 33

Vitamin B12 (cobalamin)

Front 34

Deficiency causes macrocytic, megaloblastin anemia. Hypersegmented polymorphonuclears (leukocytes) and neurologic symptoms. (Paresthesias, subacute combined degeneration) due to abnormal myelin. Prolonged deficiency leads to irreversible nervous system damage.

Back 34

Vitamin B12 (cobalamin)

Front 35

Found in animal products and synthesized only by microorganisms. Very large reserve pool stored primarily in the liver.

Back 35

Vitamin B12 (cobalamin)

Front 36

Deficiency is usually caused by malabsorption (sprue, enteritis, D. latum) lack of intrinsic factor (pernicous anemia, gastric bypass surgery) or absence of terminal ileum (Crohn's disease) Use Schilling test to detect the etiology of the deficiency

Back 36

Vitamin B12 (cobalamin)

Front 37

Important for the synthesis of nitrogenous bases in DNA and RNA. Converted to tetrahydrofolate (THF) a coenzyme for 1-carbon transfer/methylation reactions.

Back 37

Folate

Front 38

Deficiency causes macrocytic and megaloblastic anemia WITH NO NEUROLOGIC SYMPTOMS

Back 38

Folate

Front 39

Most common vit def, in USA, seen in alcoholism and pregnancy

Back 39

Folate

Front 40

From foiliage (green leaves)

Back 40

Folate

Front 41

Deficiency caused by phenytoin, sulfonamides, methotrexate

Back 41

Folate

Front 42

Dependant on vitamin B12 and folate to transfer methyl units and is required for the conversion of NE to epinephrine.

Back 42

SAM, s-adenosyl methionine

Front 43

Cofactor for carboxylation enzymes. (which add a 1-carbon group)
1. Pyruvate carboxylase: Pyruvate (3C)--> oxaloacetate (4C)
2. Acetyl-CoA carboxylase: Acetyl-CoA (3C)--> malonyl-CoA (4C)
3. Propionyl-CoA carboxylase: Propionyl-CoA (3C)--> methylmalonyl-CoA (4C)

Back 43

Biotin

Front 44

Deficiency in this is rare but causes dermatitis, alopecia, enteritis. May be caused by antibiotic use or excessive ingestion of raw eggs.

Back 44

Biotin

Front 45

An antioxidant that also:
1. Facilitates iron absorption by keeping iron in Fe2+ state (more absorbable)
2. Necessary for hydroxylation of proline and lysine in collagen synthesis
3. Necessary for dopamine beta-hydroxylase, which converts dopamine to NE

Back 45

Vitamin C (ascorbic acid)

Front 46

Found in fruits and veggies

Back 46

Vitamin C (ascorbic acid)

Front 47

Deficiency causes swollen gums, bruising, anemia and poor wound healing-- scurvy.

Back 47

Vitamin C (ascorbic acid)

Front 48

Incresease intestinal absorption of calcium and phosphate, increases bone resorption.

Back 48

Vitamin D2 and D3

Front 49

Ergocaliferol- ingested from plants and used as a pharmacologic agent.

Back 49

Vitamin D2

Front 50

Cholecalciferol- consumed in milk, formed in sun-exposed skin

Back 50

Vitamin D3.
25-OH D3- storage form
1,25- (OH)2 D3 calcitriol- active form

Front 51

Deficiency causes rickets in children (bending bones), osteomalacia in adults (soft bones) hypocalcemic tetany

Back 51

Vitamin D

Front 52

Excess causes hypercalcemia, hypercalciuria, loss of appetite, stupor. Seen in sarcoidosis (increases activation of vitamin by epitheliod macrophages)

Back 52

Excess Vitamin D

Front 53

Antioxidant (protects erythrocytes and membranes from free-radical damage)

Back 53

Vitamin E

Front 54

Deficiency causes increased fragility of erythrocytes (hemolytic anemia), muscle weakness and neurodysfunction.

Back 54

Vitamin E

Front 55

Catalyzes gamma-carboxylation of glutamic acid residues on various proteins concerned with blood clotting.

Back 55

Vitamin K

Front 56

Synthesized by intestinal flora

Back 56

Vitamin K

Front 57

Deficiency causes neonatal hemorrhage with increase PT and aPTT but normal bleeding time (neonates have sterile intestines and are unable to synthesize vitamin). Can also occur after prolonged use of broad-spectrum antibiotics.

Back 57

Vitamin K

Front 58

Which clotting factors is Vit K necessary for?

Back 58

II, VII, IX and X. Protein C and S.

Front 59

Essential for the activity of 100+ enzymes.

Back 59

Zinc

Front 60

Deficiency causes delayed wound healing, hypogonadism, decrease adult hair (axillary, facial, pucib), dysgeusia, anosmia. May predispose to alcoholic cirrhosis

Back 60

Zinc

Front 61

Protein malnutrition resulting in skin lesions, edema, liver malfunction (fatty change due to dec. apolopoprotein synthesis

Back 61

Kwashiorker

Front 62

Clinical picture of Kwashikor

Back 62

Think small child with swollen belly.
M malnutrition
E Edema
A Anemia
L Liver (Fatty)

Front 63

Energy malnutrition resulting in tissue and muscle wasting, loss of subcutaneous fat and variable edema.

Back 63

Marasmus

Front 64

Inhibits alcohol dehydrogenase

Back 64

Fomepizole

Front 65

Inhibits acetaldehyde dehydrogenase (acetaldehyde accumulates, contributing to hangover symptoms)

Back 65

Disulfiram

Front 66

Limiting reagent of ethanol metabolism

Back 66

NAD+