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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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1. How do cardia glycosides work
Directly inhibit the Na/K pump which leads to indirect inhibition of Na/Ca exchange - inc calcium inside the cell - inc cardiac contractility
AR
Alpha 1 -6 and alpha 1 -4
Palate - facial and cardiac defects

2. When does aspartate enter the urea cycle
After citruline
Liver and beta cells of pancreas - low affinity - high Km - high capacity - high Vmax - induced by insulin
N- acteylcysteine - cleave disulfide bonds within mucus glycoproteins
1 kind with multiple subunits

3. Eukaryotic and prokaryotic DNA synthesis is blank and involves both blank and blank strands
Must be both activated and inactivated for cell cycle to progress
Change resulting in early stop codon
Semiconservative - continuous and discontinuous strands (okazaki fragments)
Early in life - AR - inability to synthesize lipoproteins due to def in apoB100 and B48 - intestinal biopsy shows accumulation within enterocytes due to inability to export absorbed lipid as chylomicrons - failure to thrive - steatorrhea - acanthocyt

4. What are uncoupling agents
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
RNA poly II
HVA
Anabolic processes as a supply of reducing equivalents

5. bilateral acoustic schwannomas - juvenile cataracts
NF2 on chromosome 22
Glucose - 2Pi - 2ADP - 2NAD+
Paclitaxel
Wernicke - korsakoff - dry and wet beriberi

6. colon becomes covered witih adenomatous polyps after puberty - progresses to colon cancer unless resected
FAP
Dec in alpha ketoacid dehydrogenas leading to blocked degredation of branches amino acids like Ile - Leu - and Val - severe CNS defects mental retardation and death
Cystine kidney stones - cystine staghorn calculi - cystine is made of two cysteines connected by disulfide bond
In mitochondria - pyruvate to oxaloacetate - requires biotin - ATP - activated by acetyl coA

7. What polar group does guanine have - and what non polar group does thymine have
Macrocytic - megaloblastic anemia - hypersegmented PMNs - neurologic symptoms - (parasthesias - subacute combined degeneration) due to abnl myelin - prolonged becomes irreversible
Oxidative and nonoxidative - no ATP produced or used
Ketone - methyl
UGA - UAA and UAG

8. How many ATP are created by aerobic metabolism of glucose in the heart and liver via what shuttle
Confusion - opthalmoplegia - ataxia - confabulation - personality changes and memory loss
Orotic acid phosphoribosyltransferase or orotidine 5'- phosphate decarboxylase
Anchor muscle fibers - primarily in skeletal and cardiac muscle
32 - malate aspartate shuttle

9. What is pleiotropy and given an example
Eu - methionine - pro - formyl - methionine
1 gene had >1 effect on an individuals phenotype - PKU causes many seemingly unrelated symptoms ranging from mental retardation to hair/skin changes
Lungs - large arteries - elastic ligaments - vocal cords - ligamenta flava - stretch.
PCR - denaturation - annealing - elongation

10. cardiomegaly - systemic findings leading to early death - dz and enzyme

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11. What are the findings in orotic aciduria
Neurons
Hypophophatemia rickets - vit D resistant ricketts - inc wasting of phosphate in proximal tubule - rickets like presentation
Inc orotic acid in urine - megaloblastic anemia (does not correct with B12 or folate) - failure to thrive
CAG

12. What does the primary transcript combine with to form the spliceosome
SnRNPs and other proteins
Malonyl coa (+ biotin= palmitiate - 1 16C fatty acid)
Cystine kidney stones - cystine staghorn calculi - cystine is made of two cysteines connected by disulfide bond
CAG - 4

13. The golgi apparatus fxns as a distribution center between what organelles in the cell and What does it process
Pompe's lysosomal alpha 1 -4 glucosidase (acid maltase) (pompe trashes the pump; heart - liver - muscle)
For proteins and lipids from ER to plasma membrane - lysosomes and secretory vesicles
Sulfation
Wrinkles and acne

14. What does glycosylation of pro alpha chian yield and What is the structure
Fabrys - alpha galactosidase A - ceramide trihexoside - XR
More than 1 codon may code for the same amino acid
Same AA - often base change in 3rd position of codon (tRNA wobble)
Procollagen - triple helix of 3 alpha collagen chains

15. Which direction does dynein go
Hereditary defect of renal tubular amino acid transporter for cystein - ornithine - lysine and arginine in PCT
Post to neg
Exerts a dominant effect - a heterozygote produces a nonfxnal altered protein that also prevents the normal gene from functioning - mutation of Tx factor its allosteric site - nonfxning mutant can still bind DNA - preventing wild type Tx from binding
Eu - methionine - pro - formyl - methionine

16. What happens in vit D def
Rickets in kids - bending bones - osteomalacia in adults - hypocalcemia tetany - breast milk has dec vit D (supplement in dark skinned patients)
Type II
Ile - phe - thr - trp
Mediates extra remnant take up

17. What is the longest time of RNA and shortest
NAD+
Exerts a dominant effect - a heterozygote produces a nonfxnal altered protein that also prevents the normal gene from functioning - mutation of Tx factor its allosteric site - nonfxning mutant can still bind DNA - preventing wild type Tx from binding
MRNA - tRNA
75 to 90 - cloverleaf

18. What is the target of the 3' hydroxyl attack
Alanine
African Americans and Asians
Actin and myosin
The triphosphate bond

19. What happens to oxaloacetate in alcholism
Fed
Uses ATP to add high energy phophate group onto substrate
Excess NADH shunts oxaloacetate to malate (backwards) stalling the TCA and shunting glucose and FFA to ketone body production
Superoxide dismutase

20. What occurs to oxaloacetate in starvation and DKA
Depleted for gluconeogenesis staling the TCA cycle and shunting glucose and FFA to production of ketone bodies
Macrocytic - megaloblastic anemia - no neurologic sx - most common vit def in the US - seen in EtOH and pregs
Pantothenate - essential component of CoA - a cofactor for acyl transfers and fatty acid synthase
Liver hepatocytes and steroid producing cells of the adrenal cortex

21. In which state is FBPase -2 active
Impaired glucose breakdown leading to ATP depletion; highly affected aerobic tissues like brain and heart affected first
Fasting
Phosphenolpyruvate to pyruvate catalyzed by pyruvate kinase
MEN - 2A and 2B with ret gene

22. Name as many x- linked recessive disorders as you can

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23. What enzyme converts adenine to AMP
Robertsonian translocation and mosaicism
5' of the incoming nucleotide
Seals.
APRT + PRPP

24. How do you diagnose CFTR
Initial is heterogenous nuclear RNA - the capped and tailed is called mRNA
Prevent strands from reannealing
Chylomicrons
Inc Cl - in sweat

25. What is DNA cloning and How do you do it?
Loss of brush border enzyme causing bloating - cramps - osmotic diarrhea
Adds an inorganic phosphate onto substrate without using ATP
In ER - glucose 6- P to glucose
Production of a recombinant DNA molecule that is self perpetuating - plasmids - selection - restriction enzyme cleavage - tissue mRNA with reverse transcriptase to make cDNA

26. What is the most common urea cycle disorder and What is the mode of inheritance?
Ornithin transcarbamoylase def - x linked recesssive - other urea cycle enzymes defs are autosommal recessive
Retardation - self mutilation - aggression - hyperuricemia - gout - choreoathetosis
CGG
2 pyruvate - 2ATP - 2NADH - 2H+ - 2H2O

27. What substances inhibit phosphofructokinase -1
Glycogen synthase
Degradation of TG remaining in IDL
Mitochondria
ATP - citrate

28. What causes Down syndrome
Meiotic nondisjunction of homologous chromosomes (associated with advanced maternal age) leading to trisomy 21
Microtuble polymerization defect causing a dec in phagocytosis results in recurrent pyogenic infections - partial albinism - and peripheral neuropathy
Assistance of upper extremities to stand up
Aberrant 3rd and 4th branchial arches causing 22q11 deletion - cleft palate - abnl facies - thymic dysplasia - cardiac defects - hypocalcemia secondary to parathyroid aplasia

29. What is the activated carrier for electrons
Scrutinizes - hydrolyzes the bond
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
No mutation occuring at the locus - no selection for any genotypes at the locus - completely random mating - no migration
NADH - NADPH - FADH2

30. What are the products for glycolysis
Type II
Degradation of TG stored in adipocytes
2 pyruvate - 2ATP - 2NADH - 2H+ - 2H2O
Disease

31. energy malnutrition resulting in tissues and muscle wasting - loss of subQ fat - variable edema
Exons
GTP
Marasmus - muscle wasting
Inherited lysosomal storage disorder; failure of addition of mannose 6 phosphate to lysosomal proteins - enzymes secreted outside of cell instead of lysosomes

32. What feedback inhibits hexokinase
Glucose -6 phosphate
Regulatory proteins that control cell cycle events; phase specific; activate CDKs
Mediates chylomicron secretion
Epithelial cells

33. What are the blood glucose levels maintained by for days 1-3
No
Post to neg
Hepatic glycogenolysis - adipose tissue release of FFA - muslce and liver FFA - hepatic gluconeogenesis from peripheral tissue lactate and alanine and from adipose tissue glycerol and proprionyl - coA (odd chain FFA)
Inhibits EtOH dehydrogenase and is an antidote for methanol and ethylene glycol poisoning

34. What are the fat soluble vitamins and What does their absorption depend on...
ADEK - dependent on gut (ileum) and pancreas - accumulate in fat and can cause toxicity
Tryosine hydroxylase
Activates LCAT
Eu - methionine - pro - formyl - methionine

35. Which direction does kinesin go
Tall with long extremeties - pectus excavatum - hyperextensive joints - arachnodactyly
Neg to pos
Zero
Promotor - TATA box - and CAAT box - AT rich

36. What is the RDE of glycogenolysis
HGPRT - defective purine salvage - excess uric acid production
Aldolase B - AR - fructose 1P accumulates causing a dec in availabel phosphate which inhibts glycogenolysis and gluconeogenesis leading to hypoglycemia - cirrhosis - jaundice and vomiting
Glycogen phosphorylase
Creat a nick in the helix to relieave supercoils created during replication

37. What collagen type is most frequently affected in ehlers danlos and What are common complications
Cartilage - hyaline - vitreous body - nucleus pulposus
Y shaped region along the DNA template where leading nad lagging strands are synthesized
Chylomicrons
III - joint dislocation - anuerysms - organ rupture

38. What is the amino acid precursor for porphyrin and heme
Initial is heterogenous nuclear RNA - the capped and tailed is called mRNA
Impaired glucose breakdown leading to ATP depletion; highly affected aerobic tissues like brain and heart affected first
Glycine
Epithelial cells

39. Give an example of a mitochondrial inherited disease
More than 1 codon may code for the same amino acid
Skin
Exerts a dominant effect - a heterozygote produces a nonfxnal altered protein that also prevents the normal gene from functioning - mutation of Tx factor its allosteric site - nonfxning mutant can still bind DNA - preventing wild type Tx from binding
Lebers hereditary optic neuropathy - degeneration of retinal ganglion cells and axons - leads to acute loss of central vision. Mitochondrial myopathies

40. What is imprinting and give an example

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41. Why is albinism inheritnace varialbe due to...
Hartnup disease - dec tryptophan absoprtion - malignant carcinoid syndrome (inc tryptopha metabolism) and INH (dec vit B6)
Locus heterogeneity - ocular albinism is x- linked recessive
Activates LCAT
Mental retardation - hyperphagia - obesity - hypogonadism - hypotonia - deletion of normally active paternal allele on chromosome 15

42. What does a kinase do
Uses ATP to add high energy phophate group onto substrate
Basement membrane or basal lamina
Diphyllobothrium latum
Skin

43. What metabolic rxns occur in both the cytoplasm and mitochondria
Heme synthesis - urea cycle and gluconeogenesis - HUGs take two
Remain in G0 - regenerate from stem cells - neurons - skeletal/cardiac muscle - RBCs
Y shaped region along the DNA template where leading nad lagging strands are synthesized
Initiate chains

44. What two amino acids are required druing periods of growth and why
Arg and his inc in histones Which bind negatively charged DNA
Scrutinizes - hydrolyzes the bond
Immotile cilia due to dynein arm defect - male and femail infertile - bronchiectasis - recurrent sinusitis - associated with situs inversus
Kidney - ears - eyes

45. Where is pyruvate carboxylase found - What does it do - What does it require amd What activates it
In mitochondria - pyruvate to oxaloacetate - requires biotin - ATP - activated by acetyl coA
Dopamine beta hydroxylase
Malapsorption syndromes like sprue or CF or mineral oil intake
Tyrosine

46. In what cell is collagen synthesis initiated
Fibroblast
Many generations - both male and female affected - often pleiotropic - can present clinically after puberty
F16BP
Oxalacetate

47. What does the golgi assemble proteoglycans from
Oral uridine administration
D2 = ergocalciferol - ingested from plants D3 = cholecalciferol - ingested from milk - formed in sun exposed skin
Ornithin transcarbamoylase def - x linked recesssive - other urea cycle enzymes defs are autosommal recessive
Core proteins

48. Which part of the DNA binds RNA polymerase and multiple other TFs upstream from gene locus
Promotor - TATA box - and CAAT box - AT rich
Unwinds DNA template at replcation fork
Dec methionine - inc cystiene - inc B12/folate
Glutamine PRPP amidotransferase

49. Which RNA poly opens DNA at promotor site
UDP glucose pyrophosphorylase
RNA poly II
Asp and Glu
Promotor - TATA box - and CAAT box - AT rich

50. What are ketone bodies made from - where are they metabolized and how are they excreted
HMG- CoA - brain to 2 molecules of acetyl - Coa - excreted in urine
Kwashiorkor - small child with swollen belly
Wrinkles and acne
Glucose 6P to CO2 - 2NADPH - ribulose 5P - G6PD - rate limiting step