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Flashcards in Biochem Deck (48):
1

Pyruvate Dehydrogenase Deficiency

Lactic Acidosis, Neurologic Defects, Inc. Serum Alanine

Tx: Inc Ketogenic (Lysine, Leucine); fat intake

2

Glucose 6 Phosphate Dehydrogenase Deficiency

X-linked

Oxidative damage -> Hemolysis
Heinz bodies - oxidized hemoglobin
Bite cells

3

Fructose Metabolism

Essential Fructosuria - Fructokinase
Fructose Intolerance - Aldolase B

4

Galactose Metabolism

Galactokinase deficiency
Classic Galactosemia - Galactose 1 phosphate uridyltransferase

Infantile cataracts!!

5

Sorbital Accumulation

Lens - Retinopathy, Cataracts
Peripheral neuropathy - like in DM

No sorbital dehydrogenase

6

Essential Amino Acids

PVT TIM HaLL

Phenylalanine
Valine
Threonine
Tryptophan
Isoleucine
Methionine
Histadine
Leucine
lysine.

7

Hyperammonia

Hyperammonia - depletes alphaKG -> TCA stops

Sx: hepatic encephalopathy

Tx:
Benzoate, Phenylbutyrate - bind AA & excrete,
Lactulose - trap it as NH4 for excretion

8

Ornithine transcarbamoylase deficiency

X-linked
Inc. carbomoyl phosphate -> Inc. Orotic Acid
Inc. NH3, sx of hyperammonia

No megaloblastic anemia, Dec. BUN

9

Phenylketonuria

AR: dec. phenylalanine hydroxylase, BH4

Sx: Intellectual disability, Growth retardation, Seizures, Fair skin, Eczema, Musty Odor

Tx: Avoid Phenylalanine, Aspartame. Give Tyrosine, BH4

10

Alkaptonuria

AR: deficient homogentisate oxidase

Sx: urine turns black when exposed to air, dark connective tissue, brown pigmented sclerae, debilitating arthralgias (Homogentistic acid deposits)

11

Homocystinuria

Enzyme deficiencies:
- Cystathione Synthase, B6
- Homocysteine MethylTransferase, B12

Inc. Homocystine in urine
Intellectual Disability
Osteoporosis, Tall
Lens subluxation DOWN
Thrombosis, Atherosclerosis.

12

Cystinuria

AR: Defect of Renal tubules to secrete COLA (cysteine, ornithine, lysine, arginine)
Sx: Hexagonal Cystine Stones when pH acidic
Dx: Urinary cyanide-nitroprusside test (purple!)
Tx: Alkalinize the urine - acetazolamide

13

Maple Syrup Urine Disease

alpha ketoacid dehydrogenase (B1) - can't digest branched chain amino acids (isoleucine, leucine, valine)

Sx: urine smells like maple syrup/burnt sugar
severe CNS defects, intellectual disability, death

14

Von Gierke

Glucose 6 Phosphatase

Hypoglycemia!!
Lactate, Uric acid, Hepatomegaly inc. glycogen

15

Pompe Disease

Lysosomal alpha 1,4

Cardiomegaly, Liver failure, Muscle weakness

16

Cori Disease

Debranching enzyme (alpha 1,6)

Milder Von Gierke. No lactic acidosis

17

McArdle

Glycogen Phosphorylase

Painful muscle cramps, Myoglobinuria, Arrhythmia from electrolyte abnl.

18

Fabry's

Sx: Peripheral neuropathy, Angiokeratomas, Cardio/Renal

Deficient: Alpha galactosidase A

Accumulated: Ceramide Trihexoside

X-linked

19

Gaucher

Sx: HSM, Pancytopenia, Aseptic Necrosis of femur, Bone Crises

Histo: Gaucher cells - lipid laden macrophages - "crumpled tissue paper"

Deficient: Glucocerebrosidase

Accumulation: Glucocerebroside

20

Niemann Pick

Sx: Neurodegeneration - loss of previously acquired skills (ataxia, dysarthria), HSM, "Cherry red spot" macula

Histo: Foam cells - lipid laden macrophages

Deficient: Sphingomyelinase

Accumulation: Sphingomeylin

"No man picks (Niemann Pick) his nose without his sphinger (sphinogomyelinase)"

21

Tay Sachs

Sx: Neurodegeneration, Developmental Delay, "cherry red" macula (same as niemann pick except NO HSM)

Histo: Lysosome with onion skin

Deficient: Hexosaminidase A

Accumulation: GM2 ganglioside

"Tay SaX lacks HeXosaminidase A"

22

Krabbe disease

Sx: Peripheral neuropathy, Developmental Delay, + Optic Atrophy

Deficient: Galactocerebrosidase

Accumulation: Galactocerebroside

23

Metachromic Leukodystrophy

Sx: Central and Peripheral Demyelination, Dementia + Muscle wasting/weakness

Deficient: Arylsulfatase A

Accumulation: Cerebroside Sulfate

24

Hurler Syndrome

Sx: Developmental Delay + Gargolism + Corneal clouding + HSM

Deficient: alpha L iduronidase

Accumulation: Heparan sulfate, Dermatan sulfate

25

Hunter syndrome

Sx: Mild Hurler
+ Aggressive Behavior
-- Corneal clouding

Deficient: Iduronate sulfatase

Accumulation: Heparan sulfate, Dermatan sulfate (same)

X-linked

"Hunters see clearly (no corneal clouding) and aggressively aim for the X (X-linked)"

26

What two lysosomal storage diseases are X-linked?

Fabry
Hunter

27

What lysosomal storage diseases are increased in Ashkenazi jews?

Tay Sachs
Niemann Pick
Some forms of Gaucher

28

Carnitine Deficiency

Inability to transport FA -> mito for beta oxidation

Hypoketotic Hypoglycemia, Weakness, Hypotonia

29

Acyl CoA Dehydrogenase

Dec synthesis of acetyl coA -> dec. fasting glucose
(acetyl CoA is allosteric (+) of pyruvate carboxylase in gluconeogenesis)

30

Vitamin A (retinol)

Retina, Specialized epithelial cell differentiation (prevents squamous metaplasia), antioxidant

Used to tx: AML M3, acne, measles

Deficiency:
Eye - night blindness, corneal degen/ulceration, bitot
Dry, scaly skin, Alopecia

Toxicity:
Teratogen
Pseudotumor cerebri
Arthralgia, Scaliness, Alopecia

31

Vitamin B1 (thiamine)

1. pyruvate dehydrogenase
2. alpha ketogluturate dehydrogenase
3. branched chain ketoacid dehydrogenase
4. transketolase

Def:
Wernicke-Korsakoff
BeriBeri - Dry vs. Wet

32

Vitamin B2 (Riboflavin)

FAD, FMN
Succinate dehydrogenase

Def causes 2 C's:
Cheliosis, Corneal vascularization

33

Vitamin B3 (Niacin)

NAD, Synthesized from Tryptophan with B6

Def causes:
Pellagra - 3Ds: dermatitis, diarrhea, dementia

Causes:
- Hartnup disease (dec. tryptophan absorption)
- Malignant carcinoid (too much serotonin using up tryptophan)
- Isoniazid (dec B6)

Excess:
Facial flushing - prostaglandin
hyperglycemia
hyperuricemia

34

Vitamin B5 (Pantothenate)

Acetyl CoA stuff:
Acetyl CoA carboxylase - FA synthesis
TCA cycle: Citrate synthase

35

Vitamin B6 (Pyridoxine)

Synthesis of a lot of stuff - GABA, neurotransmitters, heme
Transamination
Decarboxylation

Def: INH, OCP
Convulsions, Hyperirritability
Peripheral Neuropathy
Sideroblastic Anemia

36

Vitamin B7 (Biotin)

Carboxylase reactions
- pyruvate carboxylase (gluconeogenesis)
- acetyl coa carboxylase (FA synthesis)
- propionyl coa carboxylase (odd chain branched FA)

Deficiency can be caused by ingestion of too many raw egg whites.

37

Vitamin B9 (Folic Acid)

Converted to THF - 1C methylation - Synthesis of RNA,DNA

Megaloblastic Anemia, Hypersegmented PMN, Glossitis
Labs: Inc. Homocysteine

Alcoholics, Preg

38

Vitamin B12 (Cobalamin)

Homocysteine Methyltransferase
Methylmalonyl CoA mutase

Megaloblastic Anemia, Hypersegmented PMN, Glossitis, NEUROLOGIC symptoms

Labs: Inc. Homocysteine AND MMA

39

Vitamin C

Scurvy - bleeding gums, brusing, hemarthrosis, subperiosteal hemorrhage, poor wound healing

40

Vitamin E

Antioxidant

Def:
Hemolytic Anemia + neuro sx like B12 deficiency, Acanthocytosis

41

Vitamin K

cofactor for gamma-carboxylation of glutamic acid residues on protein needed for clotting: 1972CS

Def inc PT, PTT

42

Zinc

Essential for 100+ enzymes

Def: delayed wound healing, hypogonadism, dec. taste, rashes

43

Mercury Poisoning

Brain, Kidney, Acrodynia - peeling of fingers

Sources: BIG fish.

44

Kwashiorkor

MEALS:
Malnutrition of Protein
Edema, Swollen belly
Anemia
Liver is fatty (can't make apolipoproteins)
Skin lesions

45

Marasmus

Total Calorie Malnutrition

Marasmus results in Muscle Wasting, Loss of SubQ fat, variable edema.

46

Reactions in BOTH cytoplasm and mitochondria

"HUGs take two:"
Heme synthesis
Urea Cycle
Gluconeogensis

47

Rxns in Mitochondria

TCA cycle, Acetyl CoA production, FA oxidation, Oxidative Phosphorylation

48

Lesch Nyhan

X-linked: ABSENT HGPRT - defective purine salvage

Hyperuricemia
Gout
Pissed off - aggression, self mutilation
Retardation
DysTonia

Tx: allopurinol, febuxostat