Biochem Review Flashcards
Name the disease:
- glucose-6-phosphatase deficiency
causes severe lactic acidosis
Treatment: feed patient ever 2-4 hours
Von Gierke’s Disease
- patient cannot do glycogenolysis in the fasting state so they get severe hypoglycemia
Name the disease:
- alpha- 1,4 - glucosidase deficiency (acid maltase)
- cannot form glucose in the heart
- S/S: hypotonia, weakness
Pompe’s Disease
- anything to do with the heart is Pompe!
Name the disease:
- alpha - 1,6- glucosidase deficiency
- debranching issue
- increased glycogen storage in spleen/liver [hepatosplenomegaly]
Cori’s Disease
Name the disease:
- alpha-1,4-glucosidase deficiency
- branching issue
Anderson’s Disease
Name the disease:
- glycogen phosphorylase deficiency
S/S: cramps after 1-3 minutes of exercise
McArdle’s Disease
Name the disease:
- glycogen phosphorylase deficiency
S/S: cramps after 10-15 minutes of exercise
HERS disease
Name the disease:
- galactose-1-phophate uridyltransferase deficiency
- causes blindness
- liver and GI issues
- intellectual disabilities
- sudden onset
Galactosemia
- need to remove all galactose and lactose from diet immediately
Name the disease:
- takes years to develop
- presents with blindness, liver, GI, and joint issues
- issue in galactose metabolism
Galactokinase Deficiency
Name the disease:
- aldolase B deficiency
- hypoglycemia
- causes liver, GI, joint issues
Fructosemia
need to remove fructose and sucrose from diet (ex. fruit/juice)
Name the disease:
- fructokinase deficiency
- benign
Fructosuria
(just need to limit fructose in diet)
Name the disease/toxicity:
- inhibits ferrochetolase
- inhibits ALA dehydratase
Lead Poisoning
Name the disease:
- problem with UV light
- deCarboxylase issue
- associated with Hep. C
Prophyria Cutanea Tarda
Name the disease:
- pink urine
- psychosis
- pain
- precipitated by meds
- polyneuropathy
- deAminase issue
Acute Intermittent Porphyria
5 P’s
Name the disease:
- build up of NH3
- Increased orotic acid
Ornithine issue
Name the disease:
- build up of NH3
- decreased Orotic acid
CPS 1 enzyme issue
Name the disease:
- overload of phenylalanine
- S/S: light skin, blue eyes, blonde hair, mousy odor, intellectual issues
PKU
(phenylalanine hydroxylase deficiency)
How do you treat PKU?
give tyrosine
Name the disease:
- subluxation of lens DOWN
- marfinoid habitus
- Kyphosis
- Intellectual disabilities
- no methionine
Homocystinuria
- can be due to a B12 deficiency
Name the disease:
- transport issue in the PCT
- COLA
Cystinuria
look for kidney stones
C- cysteine
O- ornithine
L- lysine
A- arginine
Name the disease:
- no melanocytes
(neural crest migration issue)
Albinism
tyrosine issue
- at risk for xeroderma pigmentosa
Name the disease:
- dark urine when exposed to air
- dark/blue cartilage and eyes
- causes joint pain
“moldy”
Alkaptonuria
Name the disease:
S/S: vomiting, poor feeding, cardiac issues, sweet (burnt sugar) urine
Maple Syrup Urine Disease
Cannot have
Isoleucine, Leucine, Valine
‘I love Vermont”
What are the cofactors required for any carboxylase?
A - ATP
B - Biotin
C - CO2
What are the cofactors required for any dehydrogenase?
B1-B5
What are the cofactors required for any Kinase?
Magnesium! (Mg2+)
What are the cofactors required for any transaminase?
B6
What are the cofactors required for any transketolase?
B1 (thiamine)
Name the Disease:
- alpha-galactosidase deficiency
- angiokeratomas
- renal and heart issues
Fabry Disease
Name the Disease:
- Beta glucocerebrosidase deficiency
- crumpled macrophages
- any bone issue
Gaucher’s Disease
Name the Disease:
- Sphingomyelin deficiency
- cherry red macula
- “foam cells”
- hepatosplenomegaly
Neimann-Picks Disease
Name the Disease:
- Hexosaminase deficiency
- cherry red macula
Tay Sachs Disease
Name the Disease:
- galactocerebrosidase deficiency
- Optic (CN II) Atropy
- globoid cells
Krabbe’s Disease
Name the Disease:
- alpha-L-iduronidase deficiency
- vision issues
Hurler’s Disease
Name the Disease:
- iduronate-2-sulfatase deficiency
- no vision issues
- aggressive
Hunter’s Disease
“must see 2 hunt”
What is the main source of glucose between meals?
hepatic glycogenolysis
What is the main source of glucose 1-3 days between meals?
- Muscle
- Adipose
What is the main source of glucose >3 days between meals?
Fat stores
What AA makes serotonin with B6 as a cofactor?
tryptophan
(serotonin then goes on to make melatonin)
Name the Syndrome:
- mutation of fibrillin gene on Chromosome 15
- can cause cystic medial necrosis
Marfan Syndrome
(characterized by tall build with hyper extensible joints)
Name the Syndrome:
- single transverse palmar crease
- flat nasal bridge
- low set ears
- 95% by nondisjunction
Trisomy 21 (Down Syndrome)
- also causes early onset Alzheimers
Name the Syndrome:
- rocker bottom feed
- failure to thrive
- VSD
Trisomy 18 (Edwards Syndrome)
Name the Syndrome:
- microcephaly
- cleft lip and palate
- polydactyly
- cardiac dextroposition
Trisomy 13 (Patau Syndrome)
Name the Syndrome:
- short stature
- webbed neck
- coarctation of aorta
Turner Syndrome (45, XO)
Name the Syndrome:
- lack of male secondary sex characteristics
- tall
- testicular atropy
- hypogonadism
Klinefelter Syndrome (47, XXY)
Which vitamin deficiency can cause dry skin?
Vitamin A
also Vit. A excess can cause dry skin
What Vitamin can treat AML or APML?
Vitamin A
(also used in the treatment of measles)
What Vitamin is degraded by UV light?
Vit. B2 (riboflavin)
source - MILK
What Vitamin deficiency is associated with muscle wasting or high output cardiac failure?
Vit. B1 deficiency (thiamine)
What Vitamin deficiency is associated with burning hands and burning feet?
Vit. B4 deficiency
What Vitamin deficiency is associated with burning feet ONLY?
Vit. B5 deficiency
What Vitamin deficiency is associated with Sideroblastic anemia?
Vit. B6 deficiency
What Vitamin deficiency is associated with depression?
Vitamin D
If you consume lots of raw eggs, you are now deficient of what vitamin?
Vitamine B7
A 30 yo bodybuilder comes in complaining of myalgias, anorexia, and rash. He denies anabolic steroid use but admits to large consumption of raw egg whites.
Which of the following vitamins is deficient?
Biotin - B7
What reactions use Biotin (B7) as a cofactor?
- pyruvate –> OAA
- Acetyl-CoA –> Malonyl-CoA
- Propionyl-CoA –> Methylmalonyl-CoA
A previously healthy 40yo M presents with dark urine, jaundice, and back pain. He recently ate some flat beans his wife brought home from a trip to Egypt.
Which of the following enzymes is most likely deficient in this patient?
Glucose-6-phosphate dehydrogenase
(can’t convert glucose-6-phosphate to 6-phosphogluconate)
NADPH is necessary for which biochemical reactions?
Fatty acid synthesis
What is the importance of NADPH in erythrocytes?
- maintains cell integrity during high oxidant stress by regeneration of reduced glutathione
A 2yo is brought into the ER after sudden onset of facial flushing that started an hour ago after finding the child with a vitamin supplement bottle.
Which vitamin was most likely ingested?
Niacin - B3
What can Niacin be used to treat?
Hyperlipidemia
(increases activity of lipoprotein lipase)
A 5 month old is brought to the office for poor feeding. He has difficulty keeping his head raised during feedings and suckling seems weaker. On physical exam there is noted hepatomegaly and hypotonia. Testing reveals cardiomegaly and PAS+ lysosomes.
What is the most likely diagnosis?
Pompe Disease
acid alpha-glucosidase
NORMAL glucose levels
A 15 year old patient is brought to the office for poor exercise tolerance. He has started weightlifting, but cannot keep up with peers. He mentions severe muscle cramping and discoloration of urine after activity. These symptoms can be prevented by oral glucose solution before activity.
What is the most likely diagnosis?
McArdle disease
(muscle glycogen phosphorylase)
LOW lactic acid levels
A 5 month old is brought to the office for poor feeding and greasy stools. On physical exam there is noted hepatomegaly and ultrasound shows bilateral renal enlargement. Labs show severe hypoglycemia, lactic acidosis, and increased triglycerides. Infusion of dextrose-solution improves the patient’s symptoms
What is the most likely diagnosis?
Von Gierke Disease
(glucose-6-phosphatase)
An 18 month old boy is brought to the office for neurologic regression. He had normal development until 5 months and now has difficulty sitting without support, poor head control, and loss of social smile. Height and weight are at the 5th percentile. Physical exam is notable for hepatosplenomegaly, hypotonia, and diminished deep tendon reflexes. Fundoscopy shows a bright red spot on the macula.
What is the most likely diagnosis?
Niemann-Pick disease
(sphingomyelinase deficiency)
18 month old boy is brought to the office for neurologic regression. He had normal development until 5 months and now has difficulty sitting without support, poor head control, and loss of social smile. Height and weight are at the 5th percentile. Physical exam is notable for hypotonia, and diminished deep tendon reflexes. Fundoscopy shows a bright red spot on the macula.
What is the most likely diagnosis?
Tay-Sachs disease
(B-hexosaminidase A deficiency)
accumulation of GM2 ganglioside
A 6 old boy is brought to the office for fatigue and abdominal distension. There are scattered ecchymoses on the extremities and the child appears pale. Physical exam is notable for hepatosplenomegaly, hypotonia, and diminished deep tendon reflexes. Labs show ↓ RBCs, ↓ platelets, ↓ WBCs (pancytopenia)
What is the most likely diagnosis?
Gaucher Disease
(Glucocerebrosidase deficiency)
accumulation of glucocerebroside
A fancy lab experiment is created to identify ATP sources of skeletal muscle while running on a treadmill. Which of the following pathways provides ATP within the first 10 seconds of activity?
Phosphocreatine (extremely fast!)
A 6 month old child is brought to the ER after recent onset of vomiting, irritability, and jaundice. They were exclusively breastfeed until last week when cereals and fruits were introduced to the diet.
Which of the following enzymes is most likely deficient?
Aldolase B
fructose is absorbed by GLUT-5
A 27 yo patient is found to have a hereditary defect in fructose metabolism but is otherwise asymptomatic.
Which enzyme is likely deficient?
Fructokinase
A patient with long standing type 1 diabetes presents for a followup. Despite no changes in diet, insulin, or activity levels, the patient reports more frequent episodes of hypoglycemia, but notices that the episodes are less severe than previously.
Which of the following hormonal changes is most likely responsible for the increased frequency/decreased severity of hypoglycemic episodes?
- decreased glucagon secretion secondary to alpha cell burnout
A 12 yo F is brought to the office by parents for increased severity of “growing pains”. Skin exam is notable for multiple scattered telangiectasias and angiokeratomas.
What is the most likely diagnosis?
Fabry Disease
(galactosidase-A deficiency)
A 5 month old is brought to the office for poor feeding. On physical exam there is noted hepatomegaly and hypotonia. Testing reveals hypoglycemia and ketoacidosis. Liver shows fibrosis and abnormally structured polysaccharides within hepatocytes.
What is the most likely diagnosis?
Cori Disease
(glycogen branching enzyme deficiency)
A fancy research experiment is conducted and it is found that chloride content of RBCs is much lower from the arterial sample as compared to the venous sample. Which of the following enzymes is most likely responsible?
Carbonic anhydrase
A super fancy lab experiment is done where all organelles are removed from the cell and only the cytosol remains. Which metabolic processes are still likely to be detected/unaffected?
- glycolysis
- fatty acid synthesis
- pentose phosphate pathway
An 8 yo M is evaluated for exercise intolerance. Following strenuous activity, they experience fatigue, muscle pain, and cramps. An exercise ischemic test is performed to sample blood lactate levels, but they fail to rise. Which of the following enzymes would be absent on muscle biopsy?
lactate dehydrogenase
(NAD+ depletion)
A 10 yo political refugee is brought to the office to establish care. He has had several blood transfusions in the past for anemia. Exam is notable for conjunctival pallor and moderate splenomegaly. Enzyme assay shows low pyruvate kinase activity.
Which biochemical reaction is most likely affected?
PEP –> Pyruvate
18 month old boy is brought to the ER after a generalized seizure. He had normal development until 5 months and now has difficulty sitting without support, poor head control, and loss of social smile. Height and weight are at the 5th percentile. Physical exam is notable for axial hypotonia and limb stiffness. Fundoscopy shows evidence of optic atrophy.
What is the most likely diagnosis?
Krabbe Disease
(galactocerebrosidase deficiency)
