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Biochemistry

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Answer 50 questions in 15 minutes.
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Match each statement with the correct term.
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This is a study tool. The 3 wrong answers for each question are randomly chosen from answers to other questions. So, you might find at times the answers obvious, but you will see it re-enforces your understanding as you take the test each time.

1. What is the RDE of TCA cycle
Bone - skin - tendon - dentin - fascia - cornea - late wound repair
Prevent strands from reannealing
Liver - also in kidney and gut epithelium
Isocitrate dehydrogenase

2. What CETP do
Leu - lys
Common metabolites like pyruvate and acetyl CoA and excess NH4+ converted to urea and exreted
In ER - glucose 6- P to glucose
Transfers cholesterol from mature HDL to VLDL - IDL and LDL (cholesterol ester transfer protein)

3. What does osteogenesis imperfecta causes and why
Marasmus - muscle wasting
TTP
Post to neg
Brittle bone disease - most commonly lead AD with abnl type I collagen causing multiple fractures with minimal trauma - blue sclerae due to translucency of connective tissue over the choroid - hearing loss - dental imperfections due to lack of dentin

4. For eukaryotes - Where does replication begin?
Schwann cells - lens - retina - kidneys
Consesus sequenec of base pairs
Malabsorption and steatorrhea (ADEK)
Antigen - antibody reactivity - can look for antigen or antibody in patients blood

5. What do albinism - ARPKD - CF - glycogen storage diseases - hemochromatosis - mucopolysaccharidoses (except Hunters) PKU - sickle cell - sphingolipodoses (except Fabrys) thalassemias have in common
Autosomal recessive diseases
Consesus sequenec of base pairs
Malabsorption and steatorrhea (ADEK)
One

6. Of the four possible fates for pyruvate - which one is a transition from glycolysis to TCA cycle
Anabolic processes as a supply of reducing equivalents
Inc permeability of membrane causing a dec in proton gradient and inc in O2 consumption - ATP synthesis stops - but electron transport continues to produce heat
Acetyl - CoA
Inc fragility of RBC - hemolytic anemia - muscle weakness - posterior column and spinocerebellar tract demyelination

7. What is a silent mutation
Dec AFP - inc betahCGH - dec estradiol - inc inhibin - inc nuchal translucency on US
Same AA - often base change in 3rd position of codon (tRNA wobble)
Glutamine PRPP amidotransferase
Pyruvate carboxylase - PEP carboxykinase - fructose 1 -6 biphosphatase - glucose 6 phosphatase

8. What is the target of the 3' hydroxyl attack
The triphosphate bond
Carnitine acyltransferase I
Sever atherosclerotic disease early in life - and tendon xanthomas on the achilles - MI may develop before 20
Secretion of abnl thick mucus that plugs lungs - pancreas - liver

9. What tissue samples are used for karyotyping
Avidin
Terminal regions - tropocollagen
Blood - bone marrown - amniotic fluid - placental tissue
Dermatitis - alopecia - enteritis

10. What happens do glycogen in skeletal muscle during exercise
Changed AA (convservative - new AA is similar in chemical structure)
1 kind with multiple subunits
Activates LCAT
Glycogenolysis to form glucose

11. What is anticipation and give an example
Vincritsine/vinblastine
Protein
Removes phosphate group from substrate
Severity of disease worsens or age of onset of disease is earlier in succeeding generations - huntingtons

12. What liberates glucose from glucose 6 P
1/4 of offspring from 2 carrier parents are affected - often enzyme def - usually only seen in 1 generation - often more sever than AD - presents in childhood
N- acteylcysteine - cleave disulfide bonds within mucus glycoproteins
If pt inherits or develops a mutation in a tumor suppresor gene - the complementary allele must be deleted/mutated before cancer develops - not true of oncogenes - retinoblastoma
Glucose 6 phosphatase

13. What happens in hyperammonemia
Depletes alpha - ketoglutarate leading to inhibition of TCA cycle - tremor slurring of speech - somnolence - vomiting - cerebral edema - blurring of vision
Genetic code is conserved throughout evolution - except for mito - archaebacteria - mycoplasma - and some yeast
Lariat shape in order and remove intron precisely and join 2 exons
Impaired glucose breakdown leading to ATP depletion; highly affected aerobic tissues like brain and heart affected first

14. What are the 3 AR forms of homocystinuria
Nine
Cystathionine synthase def - dec affinity of cystathionine synthase for pyridoxal phosphate - homocystein methyltransferase def
Von hippel lindau - 3
Epithelial cells

15. What two amino acids are required druing periods of growth and why
Ribose 5- P to PRPP
Binds 50S - blocking translocation
Arg and his inc in histones Which bind negatively charged DNA
Infection - free radicals generated by inflammatory response

16. metaphse chromosomes are stained - ordered and numbered according to morphology - size - arm length ratio - banding pattern
Karyotyping
Cystathionine synthase def - dec affinity of cystathionine synthase for pyridoxal phosphate - homocystein methyltransferase def
4 under the floor
Q -

17. Describe the pathophys of the aorta in a pt with marfans - and the eyes
Cystic medial necrosis of aorta leading to aortic incompetence and dissecting aortic aneurysms - floppy mitral valve - subluxation of lenses
Nonreciprocal chromosomal translocation that commonly involves chromosome pairs 13 - 14 - 15 - 21 - 22
Liver hepatocytes and steroid producing cells of the adrenal cortex
No mutation occuring at the locus - no selection for any genotypes at the locus - completely random mating - no migration

18. What shuttle is used in fatty acid degredation and What does it move and From where to where
Arginine
Carnitine shuttle - acyl - coa from cyto to mito
MRNA
Antioxidant - constituent of visual pigment - essential for nl differntiation of epithelial cells into specialized tissue (pancreatic cells - mucus secreting cells) used to treat measles

19. What is mosaicism and give an example
Inhibits 50S peptidyltransferase
40 - 60 - 80
Glycine
Occurs when cells in the body have different genetic makeup - can be germline mosaic - which may produce a disease that is not carried by parents somatic cells - lyonization - random X inactivation in females

20. Who typically has lactase def
Thiamine - in thiamine pyrophosphate a cofactor for pyruvate dehydrogenase (glycolysis) - alpha ketoglutarate dehydrogenase (TCA cycle) - transketolase (HMP shunt) - and branched - chain AA dehydrogenase
Type II
African Americans and Asians
Paclitaxel

21. Eukaryotic and prokaryotic DNA synthesis is blank and involves both blank and blank strands
Delayed wound healing - hypogonadism - dec in adult hair - dysguesia - anosmia - may predispose to EtOH cirrhosis
Oxidizes substrate
Glucose - 2Pi - 2ADP - 2NAD+
Semiconservative - continuous and discontinuous strands (okazaki fragments)

22. What does beta oxidation do and Where does it occur
Nature and severity of phenotype vary from 1 individual to another - NF type 1
Acetly- CoA - CO2 - NADH
Breaks down acyl - coa to acetyl coa groups in mito
Citrate - acetyl coa from mito to cyto

23. What are the functinos of vitamin A
Antioxidant - constituent of visual pigment - essential for nl differntiation of epithelial cells into specialized tissue (pancreatic cells - mucus secreting cells) used to treat measles
PCR - denaturation - annealing - elongation
Essential fructosuria - fructokinase AR
NAD+

24. What other complex is similar to the pyruvate dehydrogenase complex in that it has the same co - factors and generates succinyl - CoA
Tay- Sachs - hexosaminidase A - GM2 ganglioside - AR
Directly inhibit the Na/K pump which leads to indirect inhibition of Na/Ca exchange - inc calcium inside the cell - inc cardiac contractility
Alpha - ketoglutarate dehydrogenase complex
Neural tube

25. Why can't even chain fatty acids produce new glucose
They yield only acetyl - CoA equivalents
Ribose 5- P to PRPP
PFK - rate limiting enzyme
Initiate chains

26. What does the golgi apparatus do on asparagine
Ile - phe - thr - trp
Modifies N- oligosaccharides
Alcohol version of glucose - can trap glucose in cell - aldose reductase
Proton gradient

27. What are the only purely ketogenic amino acids
Citrate - isocitrate - alpha ketoglutarate - succinyl - CoA - succinate - fumarate - malate - oxaleoacetate
Antioxidant - protects RBCs and membrances from free radical damage
Lysine and leucine
Pyrophosphate (B1 - thiamine - TPP) FAD (B2 - riboflavin) - NAD (B3 - niacin) - CoA (B5 pantothenate) - lipoic acid

28. What does commaless - nonoverlapping genetic code refer to...
B100
Read from a fixed starting point as a continuous sequence of bases
AD absent of dec LDL receptors causes accelerated atherosclerosis - achilles xanthomas and corneal arcus - increase LDL and elecated cholesterol
CarTWOlage

29. What enzyme converts adenine to AMP
APRT + PRPP
Result from phagocytic removal of heinz bodies my macs - G6PD def
Autosomal recessive diseases
Same as sprint + OXPHOS

30. cytoskeletal elements in micorvilli - muscle contracting fibers - cytokenesis - adherens jxns
Actin and myosin
Facial flushing
Mutated dystrophin gene - less severe - adolescence
Orotic acid phosphoribosyltransferase or orotidine 5'- phosphate decarboxylase

31. I g fat = ? Kcal
Cre - lox system
Bind 30s subunit preventing attachment of aminoacyl - tRNA
Nine
Inc CPK and muscle biopsy

32. What is the RDE of glycogen synthesis
LDL
Thymic - parathyroid and cardiac
Convulsions - hyperirritability - peripheral neuropathy - deficiency inducible by INH and oral contraceptives - sideroblastic anemais
Glycogen synthase

33. What two rxns in in glycolysis require ATP
Cyclin dependent kinases;constitutive and inactive
Passed to glutamate - then to alanine enters blood - enters liver - coverted to pyruvate and transfers ammonium back to glutamate which gives it to the urea cycle
P2 +2pq+ = 1
Glucose to G-6P - hexokinase and fructose -6P to fructose 1 -6 BP phosphofructokinase -1

34. Describe the location and fxn of the Na/K ATPase
Miscarriage - stillbirth - chromosomal imbalance (down - patau)
Plasma membrane - 3Na out - 2K in - ATP on cytoplasmic side
Carnitine acyltransferase I
32 - malate aspartate shuttle

35. Which step in the de novo purine and pyrimidine synthesis pathway requires just aspartate
CO2 + NH4 needs carbamoyl phosphate synthase I - in the mitochondria
Orotic acid to UMP
Oxidizes substrate
Glucose to G-6P - hexokinase and fructose -6P to fructose 1 -6 BP phosphofructokinase -1

36. benign asymptomatic condition with elevated levels of fructose in urine and blood - dz and enzyme
Methionine encode by only 1 codon (AUG)
Glossitis - severe = pellagra - diarrhea - dermatitis - dementia
5' to 3'
Essential fructosuria - fructokinase AR

37. What is Retin A used topically for
32 - malate aspartate shuttle
Cre - lox system
Wrinkles and acne
Arg - lys - his - arg is most basic - has has no charge at body pH

38. What step begins the urea cycle and What is the enzyme needed - Where does it happen
Metanephrine
MRNA - tRNA
Must be both activated and inactivated for cell cycle to progress
CO2 + NH4 needs carbamoyl phosphate synthase I - in the mitochondria

39. What does lipoprotein lipase do
Acetyl - CoA carboxylase (ACC)
Degredation of TG circulating in chylomicrons and VLDLs
Must be both activated and inactivated for cell cycle to progress
FAP

40. What is the treatment for orotic aciduria
Avidin
Liver - also in kidney and gut epithelium
UGA - UAA and UAG
Oral uridine administration

41. What 3 steps in RNA processing occur after transcription

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42. What lab technique is use to profile gene expression levels of thousands of genes simultaneously to study certain diseases and treatments
Microarrays
Adds 2 carbon with the help of biotin
Riboflavin - cofactor in oxidation and reduction (FAD and FMN are derived from riboflavin)
Proline and lysine - vit C

43. What is the amino acid precuror for creatine - urea and nitric oxide
Cobalamin - cofactor of homocysteine and methyltransferase - methylmalonyl CoA mutase
HMG- CoA synthase
Ribose 5- P to PRPP
Arginine

44. cell signaling defect of fibroblast growth factor (FGF) receptor 3 - results in dwarfism - short limbs - head/trunk nl size - associated with advanced paternal age
Abnormal protein folding - degradation before reaching cell surface
Achondroplasia
Hereditary spherocytosis
Semiconservative - continuous and discontinuous strands (okazaki fragments)

45. What fxn does glucokinase serve in the liver
Histidine
UDP glucose pyrophosphorylase
Phosphorylation excess glucose to sequester it - liver becomes blood glucose buffer
Mutated dystrophin gene - less severe - adolescence

46. Infection with what organism can cause B12 def
Ribose 5- P to PRPP
Reticulin - skin - blood vessels - uterus - fetal tissue - granulation tissue
Wobble
Diphyllobothrium latum

47. recurrent pulmonary infxns in CF are due to what organisms
Retardation - self mutilation - aggression - hyperuricemia - gout - choreoathetosis
Pseudomonas and s aureus
Base + ribose
Changed AA (convservative - new AA is similar in chemical structure)

48. How do aminoglycosides work
Nonreciprocal chromosomal translocation that commonly involves chromosome pairs 13 - 14 - 15 - 21 - 22
Cofactor of carboxyltion enzymes: pyruvate carboxylase - acetate - CoA carboxylase - and propionyl - CoA carboxylase
ATP
By inhibiting formation of the initiation complex and cause misreading of mRNA

49. What enzyme catalyzes the rxn from pyrvuate to Acetyl - CoA and what inhibits it
RNA poly II
2pq
Pyruvate dehydrogenase - ATP - NADH - acetyl - CoA
Glossitis - severe = pellagra - diarrhea - dermatitis - dementia

50. What are Heinz bodies
Blood - bone marrown - amniotic fluid - placental tissue
Oxidized hemoglobin precipiated within RBCs
Cleft palate - cardiac abnl - pregs test
Glycine