Test your basic knowledge |

Biochemistry

Instructions:

Answer 50 questions in 15 minutes.
If you are not ready to take this test, you can study here.
Match each statement with the correct term.
Don't refresh. All questions and answers are randomly picked and ordered every time you load a test.

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)
Mediates extra remnant take up
2 pyruvate - 2ATP - 2NADH - 2H+ - 2H2O
ATP
Inc glucagon - inc cAMP - inc PKA

2. phosphorylation of glucose to yield glucose 6 phosphate serves as the 1st step of what rxns and what enzymes catalyze it
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
Fibrofatty replacement of muscle - cardiac myopathy
NADH - NADPH - FADH2
Glycolysis and the glycogen synthesis in the liver - hexokinase or glucokinase

3. How does ethanol induce hypoglycemia
Inc NADH/NAD ratio in liver - causing diversion of pyruvate to lactate and OAA to malate - inhibiting gluconeogenesis and stimulating fatty acid synthesis. Leads to hypoglycemia and hepatic fatty liver change seen in chronic EtOH users
Thiamine - in thiamine pyrophosphate a cofactor for pyruvate dehydrogenase (glycolysis) - alpha ketoglutarate dehydrogenase (TCA cycle) - transketolase (HMP shunt) - and branched - chain AA dehydrogenase
Promotor - TATA box - and CAAT box - AT rich
Anabolic processes as a supply of reducing equivalents

4. What is the most abundant protein in the body
SnRNPs and other proteins
Collagen
Absence of galactose 1 phosphate uridyltransferase - accumulation of toxic substances leads to failure to thrive - jaundice - hepatomegaly - infantile cataracts - mental retardation
Glycine - aspartate - glutamine

5. What creates the musty body odor in PKU
Mental retardation - flat facies - prominent epicanthal folds - simian crease - gap between 1st 2 toes - duodenal atresia - congenital heart disease (ASD) - inc risk of All and Alzheimers
Inhibits the Na/K pump by binding the K side
B100
Disorder of aromatic amino acid metabolism

6. What are the reactants for glycolysis
Glycogenolysis to form glucose
Glutamine PRPP amidotransferase
Glucose - 2Pi - 2ADP - 2NAD+
Oral uridine administration

7. benign asymptomatic condition with elevated levels of fructose in urine and blood - dz and enzyme
Rotenone - CN- - antimycin A - CO
Silencers
Makes RNA primer on which DNA poly III can initiate replication
Essential fructosuria - fructokinase AR

8. What are the findings in orotic aciduria
Dermatitis - alopecia - enteritis
Wrinkles and acne
Inc orotic acid in urine - megaloblastic anemia (does not correct with B12 or folate) - failure to thrive
Basement membrane or basal lamina

9. How does chloramphenicol work
Inhibits 50S peptidyltransferase
Heme synthesis - urea cycle and gluconeogenesis - HUGs take two
Protein kinase A
III - joint dislocation - anuerysms - organ rupture

10. What are the irreversible enzymes of gluconeogenesis
Progressive hreditary nephritis and deafness - associated with occular disturbances - due to abnl type IV collagen - usually x- linked recessive
Pyruvate carboxylase - PEP carboxykinase - fructose 1 -6 biphosphatase - glucose 6 phosphatase
VLDL
Transfers methyl units

11. congenital deficiency of homogentisic acid oxidase in the degradative pathway of tyrosine to fumarate leading to dark connective tissue - brown pigmented sclera - urine turns black on standing - dz and worst complication
Alkaptonuria - may have debiliating arthralgias
Liver hepatocytes and steroid producing cells of the adrenal cortex
Catabolic processes to carry reducing equivalents away as NADH
RER

12. What are the function of vit C
SAM
Antioxidant - facilitates iron absorption by keeping iron in the Fe2+ reduced state - necessary for hydroxylation of proline and lysine collagen bridges - necessary for dopamine beta hydroxylase which converts DA to NE
Dermatitis - glossitis - and diarrhea
Glycine - aspartate - glutamine

13. Where are the secretory proteins made and N- linked oligosaccharide addtions put on proteins
Animal products - synthesized only by microorganisms - large reserve pool - mainly in liver
1 kind with multiple subunits
RER
Reads usual codon but inserts wrong AA

14. Why can't even chain fatty acids produce new glucose
Schilling test
They yield only acetyl - CoA equivalents
Antioxidant - protects RBCs and membrances from free radical damage
Cystathionine synthase def - dec affinity of cystathionine synthase for pyridoxal phosphate - homocystein methyltransferase def

15. Inhibition of thymidilate synthase and and DHFR lead to decrease In what substance
Secretion of abnl thick mucus that plugs lungs - pancreas - liver
Microarrays
DTMP
9+2 arrangement of microtubules

16. What substance in egg whites binds biotin
Meiotic nondisjunction of homologous chromosomes (associated with advanced maternal age) leading to trisomy 21
Von Gierke's - Pompe - Cori - McArdle
Carbomoyl phosphate synthetase II
Avidin

17. How do fluoroquinolones work
Inhibit DNA gyrase specific for prokaryotic topoisomerase
32 - malate aspartate shuttle
Oxidized hemoglobin precipiated within RBCs
Removal of N or C termal propeptides from zymogens to generate mature proteins

18. What are the findings in Down's syndrome
Mental retardation - flat facies - prominent epicanthal folds - simian crease - gap between 1st 2 toes - duodenal atresia - congenital heart disease (ASD) - inc risk of All and Alzheimers
Chronic granulomatous disease - no respiatory burst - no formatino of ROS
Isocitrate dehydrogenase
Inc CPK and muscle biopsy

19. Which anti gout drugs work on microtubules
Athralgias - fatigue - headaches - skin changes - sore throat - alopecia
75 to 90 - cloverleaf
Phosphorylation excess glucose to sequester it - liver becomes blood glucose buffer
Colchicine

20. What is the RDE of ketogenesis
HMG- CoA synthase
Familial hypercholesterolemia - hyperlipidemia type IIA
Marfans
Actin and myosin

21. What is the treatment for cystathionine synthase def
Von Gierke's - Pompe - Cori - McArdle
Grows slowly - collapses quickly
ATPase that links peripheral 9 doublets and causes bending of cilium by differential sliding of doublets
Dec methionine - inc cystiene - inc B12/folate

22. What is the RDE of glycogenolysis
VMA
ATP hyrdolysis couple to energetically unfavorable rxns
Glycogen phosphorylase
Marfans

23. What co - factors are required for the pyruvated dehydrogenase complex
Pyrophosphate (B1 - thiamine - TPP) FAD (B2 - riboflavin) - NAD (B3 - niacin) - CoA (B5 pantothenate) - lipoic acid
Stored ATP - creatine phosphate - anaerobic glycolysis
ATPase that links peripheral 9 doublets and causes bending of cilium by differential sliding of doublets
Glycogen and FFA oxidation; glucose conserved for final sprinting

24. What does apoB48 do
Mediates chylomicron secretion
Carnitine shuttle - acyl - coa from cyto to mito
CAG
Aldolase B - AR - fructose 1P accumulates causing a dec in availabel phosphate which inhibts glycogenolysis and gluconeogenesis leading to hypoglycemia - cirrhosis - jaundice and vomiting

25. Which phase of the HMP shunt is reversible and Which is irreversible
Oxidative is irreversible
Oxalacetate
Delayed wound healing - hypogonadism - dec in adult hair - dysguesia - anosmia - may predispose to EtOH cirrhosis
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

26. What can excess vit B3 cause
Purines= A - G pyrimidine = C - T (U)
Phosphorylation - glycosylation - hydroxylation
Tall with long extremeties - pectus excavatum - hyperextensive joints - arachnodactyly
Facial flushing

27. NADPH are used In what 4 things
Inc dicarboxylic acids - dec in glucose and ketones
Anabolic processes like steroid and fatty acid synthesis - respiratory burst - P-450 - glutathione reductase
Reticulin - skin - blood vessels - uterus - fetal tissue - granulation tissue
Binds to LDL receptor - mediates VLDL secretion

28. What is the result of vit B5 def
Vit K antagonist
Von hippel lindau - 3
Dermatitis - enteritis - alopecia - adrenal insuff
Phenylketones in urine

29. What are the complications/signs of familial hypercholesterolemia
Sever atherosclerotic disease early in life - and tendon xanthomas on the achilles - MI may develop before 20
Oxidative and nonoxidative - no ATP produced or used
Microtuble polymerization defect causing a dec in phagocytosis results in recurrent pyogenic infections - partial albinism - and peripheral neuropathy
CAG - 4

30. What are the results of CF on male fertility
Malonyl coa
Males are infertile due to bilateral absence of vas deferens
1 -25 OH2 D3 = calcitriol
LDL

31. What makes up a nucleotide

Warning: Invalid argument supplied for foreach() in /var/www/html/basicversity.com/show_quiz.php on line 183

32. What is the energy source for translocation
Alkaptonuria - may have debiliating arthralgias
B(1 - 2 - 3 - 5 - 6 - 12) C - biotin and folate (B12 and folate are stored)
Dec DNA - dec lymphos leads to SCID
GTP

33. What substances induce phosphofructokinase
Macrocytic - megaloblastic anemia - no neurologic sx - most common vit def in the US - seen in EtOH and pregs
Acetly- CoA - CO2 - NADH
B-100 - CII and E
AMP - fructose 2 -6 BP

34. Which antihelminthe drugs work on microtubules
Mebendazole/thiabendazole
Myeloperoxidase
Males are infertile due to bilateral absence of vas deferens
Site of steroid synthesis and detoxification of drugs and poisons

35. Delivers hepatic cholesterol to peripheral tissues - formed by LPL modification of VLDL in the peripheral tissue - taken up by target cells via RME
LDL
Reticulin - skin - blood vessels - uterus - fetal tissue - granulation tissue
Absence of galactose 1 phosphate uridyltransferase - accumulation of toxic substances leads to failure to thrive - jaundice - hepatomegaly - infantile cataracts - mental retardation
1- capping on 5' (7- methyguanosine) 2 - polyadenylation on 3' end 3 - splicing out of introns

36. What part of the pre mRNA contains the actual genetic information coding for protein
Actin and myosin
Attachment of ubiquitin to defective proteins tag them for breakdown
Exons
Bone - skin - tendon - dentin - fascia - cornea - late wound repair

37. central and peripheral demyelination with ataxia and dementia
CAG
Microtubules
Exons
Metachromatic leukodystrophy - arylsulfatase A - cerebroside sulfate AR

38. What happens at the smooth ER
Mutated dystrophin gene - less severe - adolescence
Site of steroid synthesis and detoxification of drugs and poisons
SAM
Ribose 5- P to PRPP

39. In what cells do the respiratory burst occur
Carbomoyl phosphate synthetase II
Changed AA (convservative - new AA is similar in chemical structure)
PMNs
OTC has hyperammonemia - orotic aciduira does not

40. What are Heinz bodies
MRNA
Fed
Oxidized hemoglobin precipiated within RBCs
Citrate - acetyl coa from mito to cyto

41. What is the rate determining enzyme (RDE) of glycolysis
Carnitine shuttle - acyl - coa from cyto to mito
Phosphofructokinase 1
Glucose 6P to CO2 - 2NADPH - ribulose 5P - G6PD - rate limiting step
Coenzyme A - lipoamide

42. What is Retin A used topically for
Facial flushing
Wrinkles and acne
D2 = ergocalciferol - ingested from plants D3 = cholecalciferol - ingested from milk - formed in sun exposed skin
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

43. When does aspartate enter the urea cycle
After citruline
Transfers methyl units
Excess NADH shunts oxaloacetate to malate (backwards) stalling the TCA and shunting glucose and FFA to ketone body production
Diphyllobothrium latum

44. What is made fir rNucleotides or deoxyrNucleotides and what enzyme is necessary to convert one to the next
Ribos first then deoxyribos with ribonucleotide reductase
Adenylyl cycle - inc cAMP - inc PKA - glycogen phosphorylase kinase activated - glycogen phosphoylase active - glycolysis
Leu - lys
Cystathionine synthase def - dec affinity of cystathionine synthase for pyridoxal phosphate - homocystein methyltransferase def

45. What are the two possible causes of albinism
THFs
Severity of disease worsens or age of onset of disease is earlier in succeeding generations - huntingtons
Adenosine to inosine
Lack of tyrosinase (no melanin) AR ordefective tyrosine transporters (less tyrosine) - can results in lack of migration of NC cells

46. cytoskeletal elements associated with cilia - flagella - mitotic spindle - neurones and centrioles
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
Secretion of abnl thick mucus that plugs lungs - pancreas - liver
Microtubules
LDL

47. What does inc phenylalanine lead to...
Anchor muscle fibers - primarily in skeletal and cardiac muscle
Phenylketones in urine
Not all individuals with a mutant genotype show the mutant phenotype
1 ring

48. What are the characteristics of angelmans syndrome and How does it occur
Mental retardation - seizures - ataxia - inappropriate laughter - deletion of normally active maternal allele
Inhibits lipoic acid - vomiting - rice water stools - garlic breath
Nonreciprocal chromosomal translocation that commonly involves chromosome pairs 13 - 14 - 15 - 21 - 22
40 - 60 - 80

49. What is the most common urea cycle disorder and What is the mode of inheritance?
Wrinkles and acne
D2 = ergocalciferol - ingested from plants D3 = cholecalciferol - ingested from milk - formed in sun exposed skin
Phenylalanine
Ornithin transcarbamoylase def - x linked recesssive - other urea cycle enzymes defs are autosommal recessive

50. What are cyclin - CDK complexes
Must be both activated and inactivated for cell cycle to progress
Particular sequence of DNA where replicatino begins - may be single of multiple
Paclitaxel
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)