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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 energy source for tRNA actication (charging)
ATP
RNA poly II
PMNs
CO2 + NH4 needs carbamoyl phosphate synthase I - in the mitochondria

2. What are the fetal screening measures for Down
Arg - lys - his - arg is most basic - has has no charge at body pH
Attachment of ubiquitin to defective proteins tag them for breakdown
Tryosine hydroxylase
Dec AFP - inc betahCGH - dec estradiol - inc inhibin - inc nuchal translucency on US

3. What is made fir rNucleotides or deoxyrNucleotides and what enzyme is necessary to convert one to the next
Animal products - synthesized only by microorganisms - large reserve pool - mainly in liver
Ribos first then deoxyribos with ribonucleotide reductase
Riboflavin - cofactor in oxidation and reduction (FAD and FMN are derived from riboflavin)
Oxidative is irreversible

4. What does a phosphorylase do
Adds an inorganic phosphate onto substrate without using ATP
Citrate - acetyl coa from mito to cyto
Thymic - parathyroid and cardiac
Malapsorption syndromes like sprue or CF or mineral oil intake

5. Where is hexokinase found - What is its Km and Vmax and what uninduces it
Ubiquitous - low Km - high affinity - low capacity low Vmax - uninduced by insulin
Change resulting in misreading of all nucleotides downstream - usually resulting in a truncated nonfxnal protein
Lysine and arginine
NAD+

6. What makes up a nucleoside
Base + ribose
ATP hyrdolysis couple to energetically unfavorable rxns
BOne
ATP and alanine

7. What does hartnups disease cause
Seals.
Proline and glycine (non glycosylated forms)
Tryptophan excretion in urine and dec absorption from the gut leading to pellagra
Cyclin dependent kinases;constitutive and inactive

8. In addition to fructose and galactose - what sugards should be excluded from the diets of patients with disorders of fructose or galactose metabolism
Sucrose = glucose + fructose - lactose = glucose + galactose
Hereditary hemorrhagic telangiectasia (Osler - Weber - Rendu syndrome)
Hartnup disease - dec tryptophan absoprtion - malignant carcinoid syndrome (inc tryptopha metabolism) and INH (dec vit B6)
Phenylalanine hydroxylase

9. The golgi apparatus fxns as a distribution center between what organelles in the cell and What does it process
Offspring receives 2 copies of a chromosome from 1 parent and no copies from the other parent
For proteins and lipids from ER to plasma membrane - lysosomes and secretory vesicles
Directly inhibit the Na/K pump which leads to indirect inhibition of Na/Ca exchange - inc calcium inside the cell - inc cardiac contractility
Accelearted muscle breakdown

10. What stretch of DNA that alters gene expression by binding of transcription factors
Enhancers
Neurofibromatosis type 1 (von Recklinghausens disease)
Impaired glucose breakdown leading to ATP depletion; highly affected aerobic tissues like brain and heart affected first
Change resulting in misreading of all nucleotides downstream - usually resulting in a truncated nonfxnal protein

11. What is NADPH used for
Palate - facial and cardiac defects
Anabolic processes as a supply of reducing equivalents
Oxidized hemoglobin precipiated within RBCs
Exons

12. What is the prevalence of an X- linked recessive disease in males and in females
Achondroplasia
SAM
Malonyl coa (+ biotin= palmitiate - 1 16C fatty acid)
Q -

13. What does biotin def cause
UDP glucose pyrophosphorylase
HMG- CoA - brain to 2 molecules of acetyl - Coa - excreted in urine
Dec phenylalanine (contained in aspartame - Nutrasweet) inc tyrosine in diet
Dermatitis - alopecia - enteritis

14. fibrillin defect leading to connective tissue disorder affecting skeleton - heart - and eyes
Proline and lysine - vit C
Marfans
Ribulose 5P to ribose 5P - G3P and F6P - transketolase and B1
Athralgias - fatigue - headaches - skin changes - sore throat - alopecia

15. What inhibits the carnitine shuttle
Fed
Malonyl coa
Not all individuals with a mutant genotype show the mutant phenotype
Pseudomonas and s aureus

16. What is the energy source after day 3 of starvation
Adipse tissue stores - keton bodies become the main source of energy fo the brain and heart - after these are depleted - vital protein degradation accelerates - leading to organ failure and death
Base + ribose + phosphate (3' -5') phosphodiester bond
Failure to track objects or develop a social smile
Robertsonian translocation and mosaicism

17. What 3 syndromes are associated with vit B1 def
Wernicke - korsakoff - dry and wet beriberi
Prevent strands from reannealing
Transfers cholesterol from mature HDL to VLDL - IDL and LDL (cholesterol ester transfer protein)
Tuberous sclerosis

18. In what cells do the respiratory burst occur
B100
Severity of disease worsens or age of onset of disease is earlier in succeeding generations - huntingtons
RNA poly II
PMNs

19. How do permanent cells grow and regenerate and What are examples of permanent cells
Only processed RNA
Chronic granulomatous disease - no respiatory burst - no formatino of ROS
VMA
Remain in G0 - regenerate from stem cells - neurons - skeletal/cardiac muscle - RBCs

20. What does pancreatic lipase do
Liver - also in kidney and gut epithelium
Unmethylated - newly synthesized - HNPCC
Degredation of dietary TG in small intestine
Autosomal recessive diseases

21. Which are the basic amino acids
Not all individuals with a mutant genotype show the mutant phenotype
Cytosol - F 1 -6 BP to fructose 6 Phosphate
Glycogen and FFA oxidation; glucose conserved for final sprinting
Arg - lys - his - arg is most basic - has has no charge at body pH

22. What does lactase deficiency cause
ATPase that links peripheral 9 doublets and causes bending of cilium by differential sliding of doublets
Loss of brush border enzyme causing bloating - cramps - osmotic diarrhea
Poly A polymerase - signal is AAUAA
Diphyllobothrium latum

23. peripheral neuropathy - developmental delay - optic atrophy - glopoid cells
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
Phenylalanine hydroxylase - tetrahydrobiopterin cofactor
Krabbes - galactocerebrosidase - galactocerebroside - AR
RER - translation of alpha chains - usually Gly-X-Y polypeptide (preprocollagen)

24. What is mosaicism and give an example
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
Assistance of upper extremities to stand up
Fructose 1 -6 bisphosphate
ATP

25. What is the amino acid precuror for creatine - urea and nitric oxide
Coenzyme A - lipoamide
Faulty collagen synthesis - hyperextensible skin - tendency to bleed - easy bruising - hypermobile joints
Malonyl coa
Arginine

26. A small proportion of Down syndrome is due to What two genetic events
Cystic medial necrosis of aorta leading to aortic incompetence and dissecting aortic aneurysms - floppy mitral valve - subluxation of lenses
No mutation occuring at the locus - no selection for any genotypes at the locus - completely random mating - no migration
Each codon specifies only 1 amino acid
Robertsonian translocation and mosaicism

27. Synthesis of vit B3 requires what other vitamin
Trisomy 13 - severe mental retardation - rocker bottom feet - micophthlamia - microcephaly - cleft lip/palate - holoprosencephaly - polydactyly - congenital heart disease - death usually within the first year
B6
30 - glycerol -3- phosphate shuttle
Phenylketones in urine

28. Which amino acids are elastin rich in
Liver - ovaries - seminal vesicles
No - its non homologous
Proline and glycine (non glycosylated forms)
Inhibit DNA gyrase specific for prokaryotic topoisomerase

29. How many ATP are created by aerobic metabolism of glucose in the heart and liver via what shuttle
Delayed wound healing - hypogonadism - dec in adult hair - dysguesia - anosmia - may predispose to EtOH cirrhosis
32 - malate aspartate shuttle
Heterochromatin = HighlyCondensed
1 kind with multiple subunits

30. What is the TX for hyper ammonemia
Absence of galactose 1 phosphate uridyltransferase - accumulation of toxic substances leads to failure to thrive - jaundice - hepatomegaly - infantile cataracts - mental retardation
GTP hydrolysis - initiation factors assemble 40S ribosomal subunit with initiator tRNA and are released with mRNA and ribosomal subunit assemble with the complex
Limit protein diet - benzoate or phenylbutarate (both bind amino acids leading to excretion) can decrease ammonia levels
17 - 17 letters in von Recklinghausen

31. telangiectasia - recrrent epistaxis - skin discolorations - AVMs
BOne
Hereditary hemorrhagic telangiectasia (Osler - Weber - Rendu syndrome)
Alpha 1 -6 and alpha 1 -4
Deamination

32. What happens in carnitine def
CarTWOlage
Inability to transport LCFAs into mitochondria results in toxic accumulation causing weakness - hypotonia - hyperketotic hyperglycemia
In cytosol - oxaloacetate to phosphenolpyruvate - requires GTP
Neuralgia

33. What is the treatment for cystathionine synthase def
Locus heterogeneity - ocular albinism is x- linked recessive
Dec methionine - inc cystiene - inc B12/folate
Reads usual codon but inserts wrong AA
Mutated dystrophin gene - less severe - adolescence

34. What causes B12 def
For proteins and lipids from ER to plasma membrane - lysosomes and secretory vesicles
Malabsorption (sprue - enteritis) lack of intrinsic factor from pernicious anemia - gastric bypass surgery or absence of terminal ileum as in Crohns
Impaired glucose breakdown leading to ATP depletion; highly affected aerobic tissues like brain and heart affected first
Cri du chat

35. What are the symptoms of vit A def
Night blindness - dry skin
Evident in first few days of life - can present last onest - excess carbamoyl phosphate converted to orotic acid - orotic acid in blood and urine - dec BUN and symptoms of hyerpammonemia
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
Presence of both nl and mutated mtDNA resulting in mitochondrial inherited disease

36. What can excess vit B3 cause
Autosomal recessive diseases
LDL
Cytosol - F 1 -6 BP to fructose 6 Phosphate
Facial flushing

37. Where is EtOH dehydrogenase located
Cytosol
Malonyl coa
Glucose 6 phosphate dehydrogenase (G6PD)
Phenylalanine hydroxylase - tetrahydrobiopterin cofactor

38. What substances directly inhibit electron transport chain
Base + ribose + phosphate (3' -5') phosphodiester bond
Rotenone - CN- - antimycin A - CO
More than 1 codon may code for the same amino acid
FMR1 gene - methylation - associated with chromosomal breakage

39. What does the deletion of the dystrophin gene lead to...
Fructose 1 -6 bisphosphate
Cyclin dependent kinases;constitutive and inactive
Inhibits lipoic acid - vomiting - rice water stools - garlic breath
Accelearted muscle breakdown

40. What are the mRNA stop codons
Phenylketones in urine
30 - 50 - 70
Glucose - 2Pi - 2ADP - 2NAD+
UGA - UAA and UAG

41. What enzyme converts glucose 1 p to UDP glucose
Stored and undergoes glycogenolysis to maintain blood sugar at appropriate levels
No mutation occuring at the locus - no selection for any genotypes at the locus - completely random mating - no migration
UDP glucose pyrophosphorylase
Inc dicarboxylic acids - dec in glucose and ketones

42. What is the pathway in the fasting state leading to inc FBPase -2 and dec PFK-2
Hepatic overproduction of VLDL causing pancreatitis - elvelated TGs and VLDL
Assistance of upper extremities to stand up
DsRNA promotes degradation of target mRNA knocking down gene expression
Inc glucagon - inc cAMP - inc PKA

43. If two alleles are present - but the active allele is deleted - what happens
Common metabolites like pyruvate and acetyl CoA and excess NH4+ converted to urea and exreted
Keep glutathione reduced so it can detoxify free radicals and peroxides
Disease
Phosphenolpyruvate to pyruvate catalyzed by pyruvate kinase

44. What part of the pre mRNA contains the actual genetic information coding for protein
Pyruvate carboxylase - PEP carboxykinase - fructose 1 -6 biphosphatase - glucose 6 phosphatase
Base + ribose
Skin
Exons

45. What substance inside the cells replenishes NADPH
Medial dorsal nucleus of thalamus - mamillary bodies
Sons of heterozygous mothers have 1/2 half chance of being affected - no male to male transmission - and often more severe in males - heterozygous females may be affected
Ornithin transcarbamoylase def - x linked recesssive - other urea cycle enzymes defs are autosommal recessive
G6PD

46. What does amino acid catabolsim results in the formation of what?
Common metabolites like pyruvate and acetyl CoA and excess NH4+ converted to urea and exreted
They yield only acetyl - CoA equivalents
Males are infertile due to bilateral absence of vas deferens
Liver and beta cells of pancreas - low affinity - high Km - high capacity - high Vmax - induced by insulin

47. What does a carboxylase do
Pyruvate carboxylase - PEP carboxykinase - fructose 1 -6 biphosphatase - glucose 6 phosphatase
Production of a recombinant DNA molecule that is self perpetuating - plasmids - selection - restriction enzyme cleavage - tissue mRNA with reverse transcriptase to make cDNA
Adds 2 carbon with the help of biotin
Hereditary spherocytosis

48. What are the findings in Lesch - Nyhan
Unmethylated - newly synthesized - HNPCC
Cystic medial necrosis of aorta leading to aortic incompetence and dissecting aortic aneurysms - floppy mitral valve - subluxation of lenses
Athralgias - fatigue - headaches - skin changes - sore throat - alopecia
Retardation - self mutilation - aggression - hyperuricemia - gout - choreoathetosis

49. Why does alpha amanitin cause liver failure and Where is it found
Inhibits RNA polymerase II - found in death cap mushrooms
Glycogenolysis to form glucose
Hereditary defect of renal tubular amino acid transporter for cystein - ornithine - lysine and arginine in PCT
Cofactor of carboxyltion enzymes: pyruvate carboxylase - acetate - CoA carboxylase - and propionyl - CoA carboxylase

50. What does the addition of mannose -6 phosphate do
Prevent strands from reannealing
Base + ribose + phosphate (3' -5') phosphodiester bond
Alanine
Targets the proteins for lysosome