Usmle Biochem 1

Front 1

Rate Limiting Enzyme:

Glycolysis

Back 1

Phosphofructokinase-1

PFK-1

Front 2

Rate Limiting Enzyme:

Gluconeogenisis

Back 2

Fructose 1,6 bisphosphatase

F1,6 BP

Front 3

Rate Limiting Enzyme:

TCA cycle

Back 3

Isocitrate Dehydrogenase

Front 4

Rate Limiting Enzyme:

Glycogen Synthesis

Back 4

Glycogen Synthase

Front 5

Rate Limiting Enzyme:

Glycogenolysis

Back 5

Glycogen phosphorylase

Front 6

Rate Limiting Enzyme:

HMP Shunt (PPP)

Back 6

Glucose 6 phosphate dehydrogenase

G6PD

Front 7

Rate Limiting Enzyme:

Pyrimidine Synthesis (de novo)

Back 7

Carbamoyl Phosphate Synthetase II

CPS-2

Front 8

Rate Limiting Enzyme:

Purine Synthesis

Back 8

Glutamine PRPP amidotransferase

Front 9

Rate Limiting Enzyme:

Urea cycle

Back 9

Carbmoyl Phosphate Synthetase I

CPS-1

Front 10

Rate Limiting Enzyme:

Fatty acid synthesis

Back 10

Acetyl-CoA Carboxylase (ACC)

Front 11

Rate Limiting Enzyme:

Fatty acid oxidation (Beta oxidation)







BONUS: what mitochondrial enzyme deficiency results in a similar disease?

Back 11

Carnitine acyltransferase I

















BONUS: Medium Chain Acyl-CoA Dehydrogenase deficiency (MCAD) results in hypoglycemia, hypoketonemia

Front 12

Rate Limiting Enzyme:

Ketogenisis

Back 12

HMG-CoA SYNTHASE

Front 13

Rate Limiting Enzyme:

Cholesterol Synthesis

Back 13

HMG-CoA Reductase

Front 14

FOUR major enzymes in gluconeogenisis (starting at the bottom):

1.)__________________
2.)__________________
3.)__________________*
4.)__________________

Back 14

1.) Pyruvate carboxylase
2.) PEP carboxykinase
3.) Fru 1,6 BP *rate limiting
4.) Glucose 6 Phosphatase

Front 15

Glycogen phosphorylase deficiency

Back 15

McArdles Dx

Front 16

Glucose 6 Phosphatase deficiency

Back 16

VonGierkes Dx

Front 17

a-1,6 glucosidase (debranching enzyme) deficiency

Back 17

Cori Dx

Front 18

a-1,4 glucosidase deficiency

Back 18

Pompe Dx

Front 19

–Lactic acidosis
–Hyperlipidemia
–Hyperuricemia

Back 19

VonGierkes Dx

Front 20

Cardiomegaly

Back 20

Acid maltase (a-1,4 glucosidase) deficiency

Pompe (peds)

Front 21

Diaphragm weakness leading to respiratory failure

Back 21

Pompe Dx (adult)

Front 22

–Increased glycogen in liver
–Severe fasting hypoglycemia
+/-Szrs

Back 22

VonGierke Dx

Front 23

–Hepatomegaly
–Hypoglycemia
–Hyperlipidemia

–Normal kidneys
–Normal lactate levels
–Wierd lookin glycogen ("limit dextrins")

Back 23

Cori Dx

Front 24

–Painful muscle cramps
–Myoglobinuria w/strenuous exercise

Back 24

McArdle Dx

Front 25

–Severe Hepatosplenomegaly
–Enlarged Kidneys
–Short stature

Back 25

VonGierke Dx

Front 26

Ubiquitous enzyme that has a low Km and Vmax

Back 26

Hexokinase

Front 27

Insulin dependant enzyme that has a high Km and high Vmax

Back 27

Glucokinase

Front 28

What two enzyme trap glucose in the cell?

Back 28

The two enzymes that do this are:

Glucokinase
Hexokinase

Front 29

Name three substances that completely follow ZERO ORDER kinetics:

1.)_________
2.)_________
3.)_________

Back 29

PEA

1.) Penytoin
2.) EtOH
3.) ASA

Front 30

Name the FOUR major enzymes in glycolysis:

1.) Hexokinase (freebie!)
2.)_________________
3.)_________________
4.)_________________

Back 30

1.) Glucokinase;-) (liver w/insulin)

2.) Phosphfructokinase-1 (PFK-1)

3.) Glyceraldehyde Dehydrogenase

4.) Pyruvate kinase

Front 31

–Angiokeratomas

–Peripheral Neuropathy (hands/feet)

– CV dx; Renal dx

Back 31

Fabry Disease

X-linked recessive (1 of 2)

Front 32

–Aseptic necrosis of femur
–"Tissue Paper" Mø's

Back 32

Gaucher Disease

Most common

Front 33

–Hepatosplenomegaly
–Foam Cells
–Cherry red spot on macula
–Progressive Neurodegeneration

Back 33

Niemann-Pick dx

Front 34

–Lysosomes w/onion skinning
–Cherry red spot on macula
–Progressive Neurodegeneration

Back 34

Tay Sachs dx

Front 35

–Central AND Peripheral demyelination
–Ataxia
–Dementia

Back 35

Metachromic Leukodystrophy

Front 36

–Optic atrophy
–Globoid cells

–Peripheral neuropathy
–Developmental delay

Back 36

Krabbe dx

Front 37

–Hepatosplenomegaly
–Corneal clouding

–Gargoylism
–Airway obstruction
–Developmental Delay

Back 37

Hurler Syndrome

Front 38

–Agressive Behavior
–Hepatosplenomegaly

–Mild Hurler (no clouded cornea)

Back 38

Hunter Syndrome

X-linked recesssive (2 of 2)

Front 39

alpha-Galactosidase A deficiency?

Back 39

xs Ceramide trihexosdie

FABRY DISEASE

Front 40

Glucocerebrosidase deficiency?

Back 40

xs Glucocerebroside

GAUCHER DISEASE

Front 41

Sphingomyelinase deficiency?

Back 41

xs Sphingomyelin

NIEMANN-PICK DISEASE

Front 42

Hexosaminidase A deficiency?

Back 42

xs GM2 ganglioside

TAY SACHS DISEASE

Front 43

Galactocerebrosidase deficiency?

Back 43

xs Galactocerebroside

KRABBE DISEASE

Front 44

Arylsulfatase A deficiency?

Back 44

xs Cerebroside sulfate

METACHROMIC LEUKODYSTROPHY

Front 45

alpha-L-iduronidase deficiency?

Back 45

xs Heparan Sulfate
xs Dermatan Sulfate

HURLER DISEASE

Front 46

mild iduronate sulfatase deficiency?

Back 46

xs Heparan Sulfate
xs Dermatan Sulfate

HUNTER SYNDROME

Front 47

Three AA needed for PURINE Synthesis?


What are two other cofactors needed?

Back 47

Purine AAs:
Glycine
Aspartate
Glutamine

Cofactors:
THF
CO2

Pyrimidine is exactly the same, but w/o the Glycine!

Front 48

What is the treatment for:

–A megalogblstic anemia that does not correct with folate/vB12

–Increased orotic acid in urine
(absent hyperammonemia)

Back 48

Give URIDINE

(downstream orotic acid product)

Front 49

DNA mutation where AA is still the same

Base change is often in 3rd position (tRNA wobble)

Back 49

Silent mutation

Front 50

DNA mutation where AA is changed

Conservative mut.- new AA is similar to old one

Back 50

Missense mutation

(Sickle Cell Dx)

Front 51

DNA mutation where an early STOP codon is created

Back 51

Nonsense

("Stop the Nonsense!")

Front 52

DNA mutation where a single base pair is added/deleted

Usually makes a truncated, nonfunctional ptn

Back 52

Frame Shift!

FUCKED!

(often co-incides w/nonsense mut)

Front 53

DNA mutation where a Purine/Pyrimidine swap occurs

AG<---->CUT

Back 53

TransVersion

(different version of DNA)

Front 54

DNA mutation where a Purine/Purine swap or Pyrimidine/Pyrimidine swap occurs

C<----->T (U)
A<------>G

Back 54

Tran-I-stion

I-dentical product

Front 55

STOP codons
(start with U)
1.)___
2.___
3.)___

Back 55

U _ _

1.) UAA
2.) UAG
3.) UGA

Never ever UGG (bc Ugg boots are hideous)

Front 56

What disease is characterized by spliceosomal snRNP Antibodies?


(results in poor pre-mRNA splicing)

Back 56

SLE!

Front 57

Trinucleotide repeat diseases?


*HINT: Try hunting for my fried eggs*

Back 57

Tri (nucleotide)

Hunting-ton (chr 4)

My-otonic dystrophy

Fried-reich ataxia

X ("eggs") Fragile X

Front 58

Name the defective enz:

–Megaloblastic anemia (doesn't correct with vB9 or vB12)

–Failure to thrive
–Orotic acid in urine
–No hyperammonemia

Back 58

Orotic acid phosphribosyltransferase

Orotidine 5'-phosphate decarboxylase


"OROTIC ACIDURIA"

Front 59

Tx for pts with defective:

Orotic acid phosphribosyltransferase

or

Orotidine 5'-phosphate decarboxylase

Back 59

UMP (uridine- downstream product)

Front 60

What symptoms are associated with 1º Cilliary Dyskinesia (Kartagener Syndrome)?

1.) _________________
2.) Recurrent Sinusitis
3.) Infertility
4.) _________________

Back 60

Kartagener Synrome = BRIS

B ronchiectasis
R ecurrent sinusitis
I nfertility
S itus inversus

Front 61

Name the stain used for each of the following cell types:

1.) CT
2.) Muscle
3.) Epithelium

Back 61

1.) Vimentin
2.) Desmin
3.) Cytokeratin

Front 62

Collagen Products- So Be Totally Cool, Read Books!

(Name 'em)


*Hint: A strong slippery bloody BM may help!*

Back 62

S kin
B one
T endon (type I)
C artillage (type II)
R eticulin (type III)
B asement membr. (type IV)

Front 63

–Osteoporosis
–Steely depigmented hair
–Anemia
–Mental dfx
–AV tortuosity

–Ehlers Danlos mimic?

Back 63

Defective Cu+ transport

Lysyl oxidase needs Cu+ for collagen cross linking

MENKE Dx

Front 64

Name the defective enz:

Vitamin C deficiency

Back 64

Prolyl hydroxylase

(No hydroxylation occurs)

Front 65

Name the defective enz:

Osteogenisis imperfecta

Back 65

Glycosylation enz forms triple helix in Golgi


(No glycosylation (helix) occurs)

Front 66

What is the specific defect?

– Autosomal Dominant
– Cholesterol > 300
– Xanthomas

– Homozygotes have 700 cholesterol (MI in teens; IHSS mimic)

Back 66

Absent (or dfx) LDL receptor

Famial Hyperlipidemia IIA

Front 67

–Autosomal Dominant
–Recurrent Epistaxis
–Telangiectasia
–AVMs

Name this dx:

Back 67

Osler-Weber-Rendu Syndrome





(aka Hereditary-hemorrhagic telangiectasia)

Front 68

– Autosomal Dominant
– Bilateral lesions
– Polycystic liver
– Berry Aneurysm

Name the Chr. and the Gene:

Back 68

APCKD mutation

PKD1 gene
Chromosome 16

Front 69

–Autosomal Dominant
–Achondroplasia
–Assoc. w/ adv. paternal age

What is the defect?

Back 69

Cell signaling defect (FGF 3)

Front 70

– Autosomal Dominant
– Colon cancer gurantee
– Polyps (shit-ton) appear post puberty


Name the Chr. and the Gene:

Back 70

Familal Adenomatous Polyposis

APC gene
Chromosome 5

Front 71

–Autosomal Dominant
–Increased MCHC
–Splenectomy curative

–Spectrin defect

What is a common sequela to this dx?
What other defect could cause this?

Back 71

Pigmented Gallstones (d.t. hemolysis)

Ankyrin defect

Hereditary Spherocytosis

Front 72

–Autosomal Dominant
CAG repeat
Chorea
Caudate atrophy
Chrom Cuatro

What neurotransmitters are decreased?

Back 72

GABA and ACh are decreased




Huntington Dx

Front 73

–Autosomal Dominant
–Cystic medial necrosis (aortic dissection)

–Subluxation of lenses
–Floppy mitral valve


Name the defective mutation:

Back 73

Fibrillin gene mutation

Marfan Syndrome

Front 74

–Autosomal Dominant
–Lisch Nodules (iris hammartomas)


–Scoliosis
–Neural tumors
–Cafe-au-lait spots

Name the Chr. the assoc optic dfx:

Back 74

NF1 (vonRecklinghausen dx)

Chromosome 17 mut.
Optic pathway gliomas

Front 75

–Autosomal Dominant
–Bilateral acoustic schwannomas
–NF2 mut.


Name the Chr. and the assoc optic dfx:

Back 75

NF2

Chromosome 22 mut.
Juvenile Cataracts

Front 76

–Autosomal Dominant
–Retinal hammartomas
–Szrs & MR
–"ash leaf" skin spots

Name the assoc. tumors:
1.) ______________
2.) ______________
3.) ______________

Back 76

Cardiac Rhabdomyoma
Astrocytoma
Angiomyolipomas

Front 77

–Autosomal Dominant
–Hemangioblastomas of Retina/Cerebellum/Medulla

–VHL gene mutation on Chromsome 3



What is the result of this mutation?

What do half of these patients develop?

Back 77

von Hippel-Lindau disease:

Constitutively active transcription factor (HIF) for angiogenisis

50% pts develop bilateral Renal Cell Carcinomas

Front 78

–Autosomal Dominant
–CTG trinucleotide repeat
–Can't let go of door handle
–2nd MC flavor of muscular dystrophy

Back 78

Myotonic Dystrophy

Front 79

What is Fabry's Tale?

Back 79

Duke, the Muscular Hunter, Brutally Lysed the Alb-(eye)-no Gopher Without knowing it was a Fragile Hemophiliac!






Duch. dystr
Menke
Bruton
Lesch-Ny
Albinism (occular)
G6PD def.
Wiskott-Ald
Fragile X
Hemophillia

Front 80

Whats the big difference?

Duchenne muscular dystrophy

&

Becker muscular dystrophy

Back 80

DMD= frame shift mut

(Also more common & early onset)










Becker= point mut.

later onset (tweens)

Front 81

–Large jaw
–Enlarged testes
–Mitral valve prolapse

–Usually male infants
–2nd MC cause of MR
–Trinucleotide repeat CGG


What is the defective gene?

Back 81

Fragile X Syndrome =

defective expression (methylation)

FMR1 gene

Front 82

Quad screen

a-FP= low
ß-hCG= hi
Estriol= low
Inhibin A= hi

Back 82

Down Syndrome (21)

Front 83

Quad screen

a-FP= low
ß-hCG= low
Estriol= low
Inhibin A= normal

Back 83

Edward Syndrome (18)

Front 84

Quad screen

a-FP= normal
ß-hCG= normal
Estriol= normal
Inhibin A= normal

Back 84

Patau Syndrome (13)

Front 85

–Flat facies
–Epicanthal folds
–Simian crease

Which trisomy is it?
Prognosis?

Back 85

Down Syn (21)




Prognosis better: Alz dx, ALL, & AML at ages >35

Front 86

–Micrognathia
–Low set ears
–Clenched hands

Which trisomy is it? Prognosis?

Back 86

Edward Syn (18)

Death usually before 1 y.o.

Front 87

–Holoprosencephaly
–Cleft lip/palate
–Polydactyly


Which trisomy is it?
Prognosis?

Back 87

Patau Syn (13)

Death usally before 1 y.o.

Front 88

Name the four endocardial cushion defects seen in Down Syn:

1.) _____
2.) _____
3.) _____
4.) _____

Back 88

1.) VSD
2.) ASD
3.) PDA
4.) ToF

Front 89

name the 3 ugly GI diseases that are assoc. with Down Syn:

1.) ___________________
2.) ___________________
3.) ___________________

Back 89

1.) TE fistula
2.) Omphalocele
3.) Hirschprung Dx

Front 90

What the the odds a pregnant woman ≥45 y.o will have a baby with Down Syn?

Back 90

1/4

25%









BONUS: twentysomething pregnant ladys have a 1/1500 chance!

Front 91

–Microcephaly
–Epicanthal folds
–Endocardial cushion dfx
–Severe MR
–High pitched cry

Name the affected Chromosome

Back 91

Cri-du-chat = microdeletion on Chr 5



Chromosome 5

Front 92

–Friendly with strangers
–Hypercalcemia (increased Vit D sensitivity)
–Elfin facies

Name the affected Chromosome:

Back 92

Chromosome 7


William Syndrome

Front 93

What is the funKtion of Vitamin K?



:-)

Back 93

Katalyze the

Karboxylation of

glutamiK acid used in

Klotting factors

Front 94

–Dermatitis
–Alopecia
–Enteritis
–Eating too many raw eggs!

Back 94

Biotin deficiency

(avidin in eggs binds to biotin)



Antibiotics can cause biotin def too

Front 95

Cysteine
Ornithine
Arginine
Lysine

all elevated in urine... what will result?

Back 95

Hexagonal Kidney stones

Front 96

–Trinucleotide repeat GAA

–Impaired mito func
–Ataxia, pes cavus, kyphoscoliosis

What is the gene mutation?

What is the MCC of death?

Back 96

MCC of death = Hypertrophic Cardiomyopathy

Frataxin gene mutation

FRIEDREICH ATAXIA

Front 97

–vitamin that can prevent squamous metaplasia

–Contraindicated in smokers and pregnant women

Back 97

Vitamin A

Front 98

Vitamin toxicity that causes alopecia, headache, & increased ICP.

Back 98

Vitamin A

Front 99

Enzymes w/B1 cofactor
1.) Pyruvate DH
2.) alpha-Ketoglutarate dehydrogenase
3.) __________________
4.) __________________

Back 99

1.) Pyruvate Dehydrogenase
2.) alpha-Ketogluatarate Dehydrogenase
3.) Transketolase
4.) Branched Chain AA Dehydrogenase

Front 100

What is the difference between Wet Ber1ber1 and DRY BER1BER1?

Back 100

Wet Ber1ber1: High output heart failure (Dilated Cardiomyopathy) and Edema





DRY BER1BER1: Peripheral Neuropathy, Muscle Atrophy, Foot drop

Front 101

Where in the brain is the lesion in Wernike-Korsakoff? (be specific)

Back 101

Mammillary bodies






also Medial dorsal body of thalamus

Front 102

Name this classic triad:

Ophthalmoplegia
Confabulation
Ataxia

Back 102

Wernike-Korsakoff

Front 103

Vitamin def with
–Cheilosis
–Stomatitis
–Corneal Vascularization

Back 103

Riboflavin (B2)

used to make FAD and FMN

Front 104

Diarrhea, Dermatitis & Dementia

Another name for niacin deficiency?

Back 104

PELLAGRA

vB3 deficiency

Front 105

MCC of pellagra (vB3 deficiency)?

Back 105

INH prophylaxis!

Gotta give niacin to folks with TB prophylaxis

Front 106

What is the mechanism of pellagra in Hartnup disease?







*don't fat soluble vitamin deficiency. B3 is water soluble!

Back 106

Hartnup Dx:

Decreased absorption of TRYPTOPHAN

Tryp. is used to make vB3 and 5HT


By this logic, what other disease could cause a niacin deficiency? (The answer is on this slide)

Front 107

What vitamin requires the use of vB6 for synthesis?

Back 107

Vitamin B3

Niacin

Front 108

Vitamin deficiency with:

–Enteritis
–Dermatitis
–Adrenal Insufficiency

Back 108

Vitamin B5


Pantothenate

"penta-thenate" ;-)

Front 109

Vitamin cofactor for transamination (AST/ALT)

Back 109

vB6

Pyridoxime

Front 110

Vitamin deficiency with:

-Peripheral Neurophathy
–Sideroblastic anemia
–Convulsions

Back 110

Vitamin B6 def (pyridoxime def)

Neuropathy can be induced by INH and OCPs

Convulsions are caused by decreased GABA

Siderblastic anemia is caused by decreased Hgb syn. and xs Fe+

Front 111

What test would be used to determine the cause of vB12 deficiency?

Back 111

Schilling Test

Front 112

ATP + Methionine = SAM


What hormone conversion does SAM perform?

Back 112

NE to Epi conversion

Front 113

Biotin is cofactor in three important Carbon additions:

1.) Pyruvate Carboxylase
Pyruvate to OAA

2.) Acetyl-CoA Carboxylase
(___________________)

3.) Propionyl-CoA Carboxylase
(___________________)

Back 113

Biotin Cofactor:

1.) Pyruvate Carboxylase
Pyruvate to OAA

2.) Acetyl-CoA Carboxylase
Acetyl-CoA to Malonyl-CoA

3.) Propionyl-CoA Carboxlyase
Propionyl-CoA to Methylmalonyl-CoA

Front 114

What hormone conversion does Vitamin C perform?

Back 114

DA to NE

(ß-hydroxylase)

Front 115

Why do pharmacists recommend patients take their Fe+ pills with Orange Juice?

Back 115

Vitamin C helps with Fe+ absorption!!!

(Keeps iron in reduced (Fe2+) state)

Front 116

What vitamin toxicity can cause sleep problems?

Back 116

Vitamin C

Front 117

What is acrodermatitis enteropathica?

What is the cause?

Back 117

Zinc deficiency!

Rash around orafices (mouth, anus, nose, eyes)

Front 118

Vitamin deficiency with

–Dysgeusia
–Anosmia

Back 118

Zinc

also poor wound healing

Front 119

Vitamin deficiency with:

–Hypogonadism
–Decreased adult hair

Back 119

Zinc

also decreased immunity