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Flashcards in Biochem - all pathways Deck (113)
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1

Pompe Disease

signs?

enzyme defect?

severe cardiomeagly, hepatomeagly, macroglossia, hypotonia, mental retardation, glycogen accumulation in lysosomes

∆ alpha-glucosidase/acid maltase - converts branched glycogen -> glucose in lysosomes

2

McArdle Disease

signs?

enzyme defect?

increased muscle glycogen
sx occurs w/ exercise
- weakness + fatigue, little to no rise in blood lactate
- myoglobinuria
- arrhythmias + electrolyte ∆s

∆ glycogen phosphorylase - converts branched glycogen -> limit dextrans

3

Cori Disease

signs?

enzyme defect?

accumulation of small chain dextrin-like material in cytosol
hypoglycemia
hyperTg
ketoacidosis
hepatomeagly
(basically a milder version of Von-Gierke but with normal lactate levels)

∆ debranching enzyme - converts limit dextrans -> glycogen

4

RA: ∆ alpha-glucosidase/acid maltase

Pompe Disease

converts branched glycogen -> glucose in lysosomes

5

RA = ∆ glycogen phosphorylase

McArdle Disease

converts branched glycogen -> limit dextrans

6

RA = ∆ debranching enzyme

Cori disease

converts limit dextrans -> glycogen

7

Mild Galactosemia

signs?

enzyme defect?

galactosuria
cataracts (due to galacticol accumulation) - failure to tract objets, ø social smile
no hepatomeagly

∆ galactokinase - converts galactose -> galactose-1-P

8

Severe Galactosemia

signs?

enzyme defect?

trmt?

failure to thrive
intellectual disability
cataracts
hepatomeagly (due to PO4 depletion, therefore no gluconeogenesis, no glycogenolysis)

∆ G1P uridyltransferase - converts galactose-1-P -> glucose-1-P

Trmt: exclude galactose + lactose

9

RA = ∆ galactokinase

Mild Galactosemia

converts galactose -> galactose-1-P

10

RA = ∆ G1P uridyltransferase

Severe Galactosemia

converts galactose-1-P -> glucose-1-P

11

RA = trmt: exclude galactose + lactose

Severe Galactosemia

12

Cataracts, retinopathy, and peripheral neuropathy in a patient w/ poorly controlled diabetes should make you think of....

sorbitol accumulation in schwann cells, retina, and kidneys due to ∆ sorbitol dehydrogenase (converts sorbitol -> fructose)

13

Von Gierke

signs?

enzyme defect?

trmt?

severe fasting hypoglycemia
hepatomeagly (due to increased glycogen in liver)
increased blood lactate (more gets funneled down)

∆ Glucose-6-phosphatase - converts glucose-6-P -> Glucose

trmt: frequent oral glucose + starch; avoid fructose and galactose

14

RA = ∆ sorbitol dehydrogenase

sorbitol accumulation sorbitol accumulation in schwann cells, retina, and kidneys

converts sorbitol -> fructose

15

RA = ∆ Glucose-6-phosphatase

Von Gierke

converts glucose-6-P -> Glucose

16

RA = trmt: frequent oral glucose + starch; avoid fructose and galactose

Von Gierke

17

Hemolytic Anemia in PPP

signs?

enzyme defect?

hemolytic anemia w/ exposures to oxidative stress (due to øNADPH)
- sulfa Rx
- antimalarials
- infection/free radicals
- fava beans
- anti-TB Rx

∆ G6P DH - converts glucose-6-P to 6-phosphogluconate

18

Essential Fructosuria

signs?

enzyme defect?

Fructosemia + fructosuria (reducing agent in urine)

∆ fructokinase - converts fructose -> fructose-1-P

19

Fructose Intolerance

signs?

enzyme defect?

Fructosuria
decreased glycogenolysis + gluconeogenesis (due to decr. P)
sx that occur after consuming fruit juice/honey:
- hypoglycemia
- jaundice
- cirrhosis
- vomiting

∆ Aldolase B - converts fructose-1-P to glyceraldehyde

20

Hemolytic Anemia in Glycolytic Pathway

signs?

enzyme defect?

hemolytic anemia (due to ø glycolysis and ø ATP to maintain RBC structure)

∆ pyruvate kinase - converts PEP -> Pyruvate

21

RA: ∆ G6P DH

Hemolytic anemia due to PPP

converts glucose-6-P to 6-phosphogluconate

22

RA: ∆ Fructokinase

Essential Fructosuria

converts fructose -> fructose-1-P

23

RA: ∆ Aldolase B

Fructose Intolerance

converts fructose-1-P to glyceraldehyde

24

RA: ∆ pyruvate kinase

hemolytic anemia in glycolytic pathway

converts PEP -> Pyruvate

25

∆ pyruvate carboxylase

downregulation of Citric acid cycle/energy producing capacity of the cell

converts Pyruvate -> oxaloacetate

26

∆ pyruvate dehydrogenase

signs?

trmt?

Lactic acidosis
increase serum alanine
neurological defects

trmt: increase fat, lysine, leucine

converts pyruvate -> Acetyl CoA

27

arsenic blocks these two enzymes

net ATP?

pyruvate DH
alpha-ketoglutarate DH

net: 0 ATP

28

Symptoms due to defects in carnitine shuttle

hypoketoic
hypoglycemia
hyptonia (weakness)

29

∆ Acyl-CoA DH

low fasting glucose

30

Maple Syrup Disease

signs?

enzyme defect?

trmt?

CNS defects (retardation)
urine that smells like burnt sugar/maple syrup

∆ alpha-keto acid dehydrogenase - converts branched chain a.a. to propionyl CoA

trmt: decrease isoleucine, leucine, valine, increase thiamine (B1)