click below
click below
Normal Size Small Size show me how
Biochemistry Q&A
First Aid Q&A: Biochemistry
Question | Answer |
---|---|
X-linked recessive deficiency of alpha-galactosidase A resulting in an accumulation of ceramide trihexoside. Symptoms include angiokeratomas and deposition in the vascular endothelium. Diagnosis? | Fabry's disease |
Galactocerebroside accumulations as a result of galactosylceramide alpha-galactosidase deficiency. Symptoms include optic atrophy, spasticity, and depositions in the brain leading to early death. Diagnosis? | Krabbe's disease |
Sphingomyelin and cholesterol buildup leading to death by age 3. Disease and deficiency? | Niemann-Pick disease; Sphingomyelinase |
ADH receptor in the kidney? | V2 |
ADH receptor in vascular smooth muscle? | V1 |
Dark colored joints and cartilage and dark colored urine. Diagnosis and deficiency? | Alkaptonuria; homogenistic acid oxidase |
Sacroiliac arthritis and eventual loss of mobility in the spine (bamboo spine). Diagnosis? | Ankylosing spondylitis |
Blocked degradation of branched amino acids. Disease and amino acids? | Maple Syrup Urine disease; Isoleucine, leucine, and valine (I love vermont maple syrup!) |
In smooth muscle contraction, Ca-calmodulin complex binds this enzyme leading to myosin and actin binding. | Myosin light chain kinase; phosphorylates myosin allowing it to bind actin |
This molecule, in high concentrations, can activate ATPases, phospholipases, endonucleases, and several proteases resulting in significant cell injury? | Calcium |
If a compound A has a higher affinity for a receptor than compound B, which will have the higher Km? | Compound B; Km is the concentration at which velocity equals Vmax/2. Since A has a higher affinity, it follows that it will achieve Vmax at a lower concentration, and thus have a smaller Km. |
Deficiency of uroporphyrinogen I synthetase. Diagnosis and what will be found in the urine? | Acute intermittent porphyria; delta-ALA and porphobilinogen |
Coagulopathy associated with hypercoagulability. Patient presents with swollen, painful, and red extremities | Factor V Leiden deficiency; resistance to activated protein C |
In this disorder requiring multiple transfusions, deposition in various tissues such as pancreas, heart, and skin result in RUQ discomfort, browner skin tone, elevated glucose, hemolysis, and restrictive cardiomyopathy. | Beta-thalassemia; iron deposition is cause of symptoms |
Intrinsic defect in the body's ability to control the absorption of iron. Diagnosis? | Hereditary hemochromatosis |
Accumulations of this substance in liver, brain, and cornea lead to parkinsonian symptoms,, Kayser-Fleischer rings, asterixis, and dementia. Diagnosis? | Wilson's disease; failure of copper to enter the circulation in the form of ceruloplasmin |
Symmetrical proximal muscle weakness due to degeneration of the anterior horn cells of the spinal cord. Diagnosis? | Spinal muscular atrophy |
X-linked recessive disorder leading to progressive muscle weakness starting before age 5 with patients often wheelchair dependent by 10-12 years old. | Duchenne's or Becker's; defective dystrophin protein |
Where are the GLUT1, GLUT2, and GLUT4 glucose transporters located and which are insulin responsive? | GLUT1 are found on RBC's and brain; GLUT2 are found beta islets and hepatocytes; GLUT4 are found on adipocytes and skeletal muscle and are insulin responsive |
What type of test is used to determine if a person is a carier of the cystic fibrosis gene? | PCR amplification followed by sequencing |
What is the binding site of vancomycin and what bacteria are it effective against? | Gram positive cocci; it binds to the amino acid sequence D-ala Dala preventing cell wall synthesis. |
Syndrome characterized by recurrent sinusitis, bronchiectasis, and situs inversus. Diagnosis? | Kartagener's syndrome |
What are the 4 characteristics of tetralogy of falot? | Pulmonary stenosis, VSD, overriding aorta, and RVH |
This defect in the ornithine transcaramoylase leads to mental retardation, seizures, and ultimately death. What is the reason for these symptoms? | Hereditary hyperammonemia; the enzyme is a component of the urea cycle and results in elevated ammonia in the blood. |
Seasonal allergies are the result of what receptor activation? | Histamine 1 receptor (histamine 2 receptors are on gastric parietal cells) |
Glycogen storage disease leading to cardiomegaly. Diagnosis and deficient enzyme? | Pompe's disease; deficient alpha 1,4-glucosidase |
Type I familial dyslipidemia results in an elevation of what lipid? | lipoprotein lipase deficiency; elevated TG's rich lipoproteins |
What are the 3 elements of Virchow's triad? | vessel trauma, stasis, hypercoagulability |
CNS tumor associated with tuberous sclerosis? | Astrocytoma |
This type of cancer is associated with inadequate nucleotide excision repair? | Squamous cell carcinoma (xeroderma pigmentosum) |
Intracellular second messenger of all hypothalamic hormones, with one exception? | PLC-IP3; CRH is the one exception (cAMP) |
How do steroids exert their actions upon a cell? | Cross membrane, bind cytosolic receptor, travel to the nucleus, increase transcription |
This drug works by stabilizing the mitotic spindle preventing microtubules from depolymerizing. | Paclitaxel |
What is the MOA of bleomycin and it's characteristic toxicity? | Incercalates DNA; characteristic toxicity is pulmonary fibrosis |
What is the MOA of cyclophosphamide and it's characteristic toxicity? | DNA alkylator; hemorrhagic cystitis |
Pyrimidine analog that interferes with thymidylate synthase? | 5-fluorouracil |
Inhibitor of dihydrofolate reductase inhibitor? | Methotrexate |
What are the essential amino acids? | PriVaTe TIM HALL; phenyalanine, valine, threonine, tryptophan, isoleucine, methionine, histidine, arginine, leucine, lysine |
What two features distinguish B12 deficiency from folate deficiency? | neurological symptoms and elevated methylmalonic acid |
Deficiency of this vitamin results in diarrhea, dementia, and dermatitis? | Pellagra; caused by B3 deficiency |
Disease characterized by skeletal abnormalities, restricted joint movement, coarse facial features, and severe psychomotor impairment with death occurring by age 8? | I-cell disease; failure of addition of mannose-6-phosphate |
Deficiency of tyrosinase is often the cause of this disorder? | Albinism |
With obstructive liver disease, would you expect bilirubinemia to be conjugated or unconjugated, urine urobilinogens to be increased or decreased, and urine bilirubin to be increased or decreased, respectively? | conjugated; increased urine bilirubin; decreased urine urobilinogen |
With hemolytic jaundice, would you expect bilirubinemia to be conjugated or unconjugated, urine urobilinogens to be increased or decreased, and urine bilirubin to be increased or decreased, respectively? | Unconjugated; decreased urine bilirubin; increased urine urobilinogen |
Chronic alcoholic with severe epigastric pain radiating to the back, nausea, vomiting, hx of gallstones. Increased serum lipase and amylase. Diagnosis? | Acute pancreatitis |
Deficiency of tetrahydrobiopteran cofactor or this enzyme will result in mental and growth retardation, fair skin, eczema, and a musty body odor? | Phenylalanine hydroxylase; PKU |
3 month old with history of unusual infection by pneumocystis carinii and candida albicans, also demonstrating failure to thrive. Diagnosis? | SCID; attributed ot a deficiency of adenosine deaminase of purine salvage system, unable to complete B and T cell DNA synthesis |
What is the treatment for excess oxidized hemoglobin? | Methemoglobinemia; treated with methylene blue |
Dipalmitoyl phosphatidylcholine is secreted by what cells? | Surfactant; secreted by type II pneumocytes |