Brainscape's Knowledge GenomeTM

Browse over 1 million classes created by top students, professors, publishers, and experts.


See full index

Step 1 Flash Cards > Metabolism > Flashcards

Metabolism Flashcards

1
Q

rate limiting enzyme of glycolysis

A

phosphofructokinase-1

    • inhibited by ATP, citrate
    • stimulated by AMP and fruc-2,6-BP
How well did you know this?
1
Not at all
2
3
4
5
Perfectly
2
Q

rate limiting enzyme of gluconeogenesis

A

fructose-1,6-bisphosphatase

  • -stimulate by ATP, AcetylCoA
    • inhibited by AMP, fruc-2,6-BP
How well did you know this?
1
Not at all
2
3
4
5
Perfectly
3
Q

rate limiting enzyme of TCA cycle

A

isocitrate dehydrogenase

  • stimulated by ADP
  • inhibited by ATP, NADH
How well did you know this?
1
Not at all
2
3
4
5
Perfectly
4
Q

rate limiting enzyme of glycogenesis

A

glycogen synthase
+ G6P, insulin, cortisol
- epi, glucagon

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
5
Q

rate limiting enzyme of glycogenolysis

A

glycogen phosphorylase
+ epi, glucagon, AMP
- G6P, insulin, ATP

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
6
Q

rate limiting enzyme of HMP shunt

A

G6PD
+ NADP+
- NADPH

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
7
Q

rate limiting enzyme of cholesterol synthesis

A

HMG-CoA reductase
+ insulin, thyroxine
- glucagon, cholesterol

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
8
Q

electron transport inhibitors

A

rotenone, cyanide, antimycin A, CO

– directly inhibit electron transport, causing a decreased proton gradient and block of ATP synthesis

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
9
Q

ATP synthase inhibitors

A

oligomycin
– directly inhibits mitochondrial ATP synthase, causing increased H+ gradient. No ATP is produced because electron transport stops

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
10
Q

uncoupling agents

A

2,4-dinitrophenol, aspirin, thermogenin in brown fat
– increase permeability of mito membrane, causing decreased H+ gradient and increased O2 consumption. electron transport continues without ATP synthesis, produces heat.

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
11
Q

Von Gierke Disease (type I)

A

glycogen storage disease with severe fasting hypoglycemia, increased glycogen in liver, increased blood lactate and hepatomegaly

    • G6Phosphatase deficient
    • treat with frequent oral glucose/cornstarch, avoid fructose and galactose
How well did you know this?
1
Not at all
2
3
4
5
Perfectly
12
Q

Pompe Disease (type II)

A

glycogen storage disease with cardiomyopathy and systemic findings leading to early death

    • lysosomal alpha 1,4 glucosidase (acid maltase) deficient
    • Pompe trashes the Pump (heart liver muscle)
How well did you know this?
1
Not at all
2
3
4
5
Perfectly
13
Q

Cori disease (type III)

A

milder form of type I (Von Gierke) glycogen storage disease with normal blood lactate levels

    • debranching enzyme (1,6 glucosidase) deficient
    • gluconeogenesis is inact
How well did you know this?
1
Not at all
2
3
4
5
Perfectly
14
Q

McArdle disease (Type V)

A

glycogen storage disease with increased glycogen in muscle, but cannot break it down, leading to painful muscle cramps, myoglobinuria after exercise, and arrthythmias 2/2 electrolyte abnormalities

    • skeletal muscle glycogen phosphorylase deficiency
    • McArdle = Muscle
How well did you know this?
1
Not at all
2
3
4
5
Perfectly
15
Q

Fabry disease

A
    • alpha galactosidase A deficiency
    • ceramide trihexoside builds up
    • X linked inheritance
    • peripheral neuropathy, angiokeratomas, CV/renal disease
How well did you know this?
1
Not at all
2
3
4
5
Perfectly
16
Q

Gaucher disease

A
    • most common lysosomal storage disease
    • glucocerebrosidase deficiency –> glucocerebroside buildup
    • hepatosplenomegaly, pancytopenia, aseptic necrosis of the femur, bone crises, Gaucher cells (lipid laden resembling crumpled tissue paper)
    • treat with recombinant enzyme
How well did you know this?
1
Not at all
2
3
4
5
Perfectly
17
Q

Neimann-Pick Disease

A
    • sphingomyelinase deficiency leads to buildup of sphingomyelin
    • progressive neurodegeneration, HSmegaly, cherry red spots on macula, foam cells (lipid-laden macrophages)
    • “No man picks his nose with his sphinger (sphingomyelinase)”
18
Q

Tay-Sachs Disease

A
    • hexosaminidase A deficiency –> buildup of GM2 ganglioside
    • progressive neurodegeneration, developmental delay, “cherry-red” spots on macula, lysosomes with onion skin, no HSmegaly
  • -Tay SaX (heXosamindase)
19
Q

Krabbe disease

A
    • galactocerebrosidase deficiency –> buildup of galactocerebroside and psychosine
    • peripheral neuropathy, developmental delay, optic atrophy, globoid cells
20
Q

Metachromatic leukodystrophy

A
    • arylsulfatase A deficiency –> buildup of cerebroside sulfate
    • central and peripheral demyelination with ataxia, dementia
21
Q

Hurler Syndrome

A
    • alpha-L-iduronidase deficiency leading to heparan sulfate and dermatan sulfate buildup
  • Dont give Hurler Harry a cookie - developmental delay, gargoylism, Hurler, HSmegaly, airway obstruction, corneal clouding
22
Q

Hunter syndrome

A
    • XR iduronate sulfase deficiency leading to heparan sulfate and dermatan sulfate buildup
    • milder Hurler syndrome +aggressive behavior and NO corneal clouding
    • Hunters see clearly (no corneal clouding) and aim for the X (X-linked recessive)
23
Q

arsenic

A

inhibits lipoic acid, a cofactor needed for pyruvate dehydrogenase complex
– leads to vomiting, rice-water stools and garlic breath

24
Q

G6PD deficiency

A

decreased NADPH in RBCs leads to hemolytic anemia after oxidative stress because NADPH cannot keep glutathione reduced, which in turn cannot detoxify free radicals

    • more common in blacks
    • Heinz bodies and bite cells seen
25
Q

essential fructosuria

A

benign condition due to defect in fructokinase

– fructose appears in the blood and urine

26
Q

fructose intolerance

A

hereditary deficiency in aldolase B leads to F-1P to build up, which results in inhibition of glycogenolysis and gluconeogenesis

    • hypoglycemia, jaundice, cirrhosis and vomiting following consumption of fruit, juice or honey
    • reducing sugar found in urine
    • treat with decreased fructose and sucrose
27
Q

galactokinase deficiency

A

hereditary deficiency leads to buildup of galactitol

    • relatively mild condition with galactose in blood and urine
    • infantile cataracts, lack of tracking, dont develop social smile
28
Q

classic galactosemia

A

absence of galactose-1-phosphate uridyltransferase leads to buildup of galactitol

    • failure to thrive, jaundice, hepatomegaly, infantile cataracts, intellectual disability
    • exclude galactose and lactose from diet
29
Q

ornithine transcarbamylase deficiency

A

most common urea cycle disorder

    • X-linked recessive
    • excess carbamoyl phosphate is converted to orotic acid
    • findings: increased orotic acid in blood and urine, decreased BUN, symptoms of hyperammonemia, no megaloblastic anemia
30
Q

phenyketonuria

A

due to decreased phenylalanine hydroxylase or decreased tetrahydrobiopterin cofactor

    • tyrosine becomes essential, phenylketones found in urine
    • intellectual disability, growth retardation, seizures, fair skin, eczema, musty body odor
    • treat with decease phenylalanine and increased tyrosine in diet
31
Q

alkaptonuria

A

congenital deficiency of homogentisate oxidase in the degradative pathway of tyrosine to fumarate

    • AR benign disease with dark connective tissue, brown pigmented sclera with urine that turns black when exposed to air
    • can have disabling arthralgias
32
Q

homocystinuria

A

3 forms, all resulting in excess homocysteine
– increased homocysteine in urine, intellectual disability, osteoporosis, tall stature, kyphosis, downward lens subluxation, thrombosis and atherosclerosis

33
Q

cystinuria

A

hereditary defect of renal and intestinal AA transporter for cystine, ornithine, lysine, and arginine (COLA)

    • excess cystine in the urine can lead to hexagonal cystine stones
    • urinary cyanide-nitroprusside test is diagnostic
    • treat with urinary alkalinization and good hydration
34
Q

maple syrup urine disease

A
    • blocked degradation of branched AA (isoleucine, leucine and valine)
    • increased alpha ketoacids in the blood, esp those of leucine
    • severe CNS defects, intellectual disability and death
    • treat with restriction of ILV in diet, and thiamine supplementation
35
Q

5 cofactors required for alpha-ketoacid dehydrogenase, pyruvate dehydrogenase, and alpha-ketoglutarate dehyrogenase

A

Tender Loving Care For Nancy

  • thiamine pyrophosphate
  • lipoate
  • coenzyme A
  • FAD
  • NAD
36
Q

type I hyperchylomicronemia

A

increased chylomicrons, TG and cholesterol

    • AR lipoprotein lipase deficiency or altered apolipoprotein C-11
  • causes pancreatitis, HSmegaly, and eruptive/pruritic xanthomas (no increased atherosclerosis)
37
Q

type IIa familial hypercholesterolemia

A
  • increased LDL, cholesterol
  • AD, absent or defective LDL receptors
  • hetero - 330mg/dL, homo - 700+
  • accelerated atherosclerosis, tendon xanthomas, and corneal arcus
38
Q

type IV hypertriglyceridemia

A
  • elevated VLDL, TG
  • AD, hepatic overproduction of VLDL
  • causes pancreatitis
39
Q

orotic aciduria

A

inability to convert orotic acid to UMP in pyrimidine sythesis

  • presents with megaloblastic anemia resistant to folate and B12, growth retardation and neuro abnormalities
  • no hyperammonemia signs like ornithine transcarbamylase deficiency (urea cycle d/o)
  • supplement with uridine
40
Q

propionic acidemia

A
  • propionyl CoA caboxylase deficiency that leads to the buildup of propionic acid in the breakdown of branched chain amino acids (valine, isoleucine, threonine, methionine)
  • presents with poor feeding, lethargy, hypotonia, dehydration and anion gap acidosis during the first few days of life

Step 1 Flash Cards (36 decks)

Brainscape helps you reach your goals faster, through stronger study habits.
© 2024 Bold Learning Solutions. Terms and Conditions