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 do DNA topoisomerases do
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
MRNA - tRNA
Mucus secreting globlet cells and antibody secreting plasma cells
Creat a nick in the helix to relieave supercoils created during replication

2. Outside the fibroblast What part of procollagen is cleaved and What is it transformed into
RNA poly II
Hypercalciuria - loss of appetite - stupor - seen in sarcoidosis from activation fo vit D by epithelioid macrophage
Terminal regions - tropocollagen
Von hippel lindau - 3

3. What are the complications/signs of familial hypercholesterolemia
X- linked recessive
Sever atherosclerotic disease early in life - and tendon xanthomas on the achilles - MI may develop before 20
Glutamate
RRNA

4. What does apoCII do
5' to 3'
Ile - phe - thr - trp
Cofactor for LPL
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

5. How do glucagon/epi lead to glycogenolysis
Exercise: inc NAD/NADH - inc ADP - inc Ca
Alanine
PMNs
Adenylyl cycle - inc cAMP - inc PKA - glycogen phosphorylase kinase activated - glycogen phosphoylase active - glycolysis

6. Which kind of osteogenesis imperfecta is fata in utero or in neonatal period
PFK - rate limiting enzyme
Type II
After day 1
Initial is heterogenous nuclear RNA - the capped and tailed is called mRNA

7. phosphorylation of glucose to yield glucose 6 phosphate serves as the 1st step of what rxns and what enzymes catalyze it
Glucose -6 phosphate
Oxidizes substrate
Glycolysis and the glycogen synthesis in the liver - hexokinase or glucokinase
Cheilosis - inflammation of lips - scaling and fissures at the corner of the mouth - corneal vascularization

8. What components come together to make S- adenosyl methionine
Assistance of upper extremities to stand up
PCR - denaturation - annealing - elongation
Inc vit B6
ATP and methionine

9. Type IV BM
Severity of disease worsens or age of onset of disease is earlier in succeeding generations - huntingtons
Inhibits EtOH dehydrogenase and is an antidote for methanol and ethylene glycol poisoning
Abnormal protein folding - degradation before reaching cell surface
4 under the floor

10. What is the most abundant type of RNA
RRNA
Methionine encode by only 1 codon (AUG)
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)
Alpha 1 -4 glucosidase

11. The golgi apparatus fxns as a distribution center between what organelles in the cell and What does it process
HMG- CoA - brain to 2 molecules of acetyl - Coa - excreted in urine
Poor defense from oxidizing agents - fava beans - sulfonamides - primaquine - antituberclosis drugs leadig to hemolytic anemia.
Remain in G0 - regenerate from stem cells - neurons - skeletal/cardiac muscle - RBCs
For proteins and lipids from ER to plasma membrane - lysosomes and secretory vesicles

12. Which step in the de novo purine and pyrimidine synthesis pathway requires aspartate - glycine - glutamine and THF
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
Liver hepatocytes and steroid producing cells of the adrenal cortex
Ribose 5- P to PRPP
Terminal regions - tropocollagen

13. what gene is implicated in fragile X syndrome - and What is the mutation
Supply sufficient glucose to brain and RBCs and to preserve protein
FMR1 gene - methylation - associated with chromosomal breakage
Zero
Presence of both nl and mutated mtDNA resulting in mitochondrial inherited disease

14. What is the pathway in the fed state leading to dec FBPase -2 and inc PFK-2
Inc insulin - dec cAMP - dec PKA
Flank pain - hematuria - HTN - progressive renal failure
Mcardle's - skeletal muscle glycogen posphorylase
Liver and leafy veggies

15. What are the characteristics of angelmans syndrome and How does it occur
Production of a recombinant DNA molecule that is self perpetuating - plasmids - selection - restriction enzyme cleavage - tissue mRNA with reverse transcriptase to make cDNA
DTMP
Marfans
Mental retardation - seizures - ataxia - inappropriate laughter - deletion of normally active maternal allele

16. What occurs to oxaloacetate in starvation and DKA
Disorder of aromatic amino acid metabolism
Cystathionine synthase def - dec affinity of cystathionine synthase for pyridoxal phosphate - homocystein methyltransferase def
Depleted for gluconeogenesis staling the TCA cycle and shunting glucose and FFA to production of ketone bodies
Pantothenate - essential component of CoA - a cofactor for acyl transfers and fatty acid synthase

17. What is the breakdown product of dopamine
Cytosol - F 1 -6 BP to fructose 6 Phosphate
HVA
Changed AA (convservative - new AA is similar in chemical structure)
Directly inhibit the Na/K pump which leads to indirect inhibition of Na/Ca exchange - inc calcium inside the cell - inc cardiac contractility

18. 1 g of protein or cabrohydrate = ?kcal
Macrocytic - megaloblastic anemia - no neurologic sx - most common vit def in the US - seen in EtOH and pregs
Homocystein in ruine - mental retardation - osteoporosis - tall stature - kyphosis - lens subluxation and atherosclerosis leading to stroke and MI - cysteine
Dermatitis - glossitis - and diarrhea
Four

19. What do neurofilaments stain for
Neurons
Glycolysis and the glycogen synthesis in the liver - hexokinase or glucokinase
Comlex II
Phosphorylation - glycosylation - hydroxylation

20. What is the hardy weinberg allele prevalence
Exons
Epithelial cells
P+q = 1
Result from phagocytic removal of heinz bodies my macs - G6PD def

21. Severe fasting hypoglycemia - inc glycogen storage in liver - inc blood lactate - hepatomegaly - dz and def enzyme
Cofactor for LPL
Glycogen phosphorylase
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
Von gierkes - glucose 6 phosphatase

22. What is the TX for pyruvate dehydrogenase deficiency
Degradation of TG stored in adipocytes
Metanephrine
CarTWOlage
Inc intake of ketogenic nutrients - high in fact content or inc lysine or leucine

23. metaphse chromosomes are stained - ordered and numbered according to morphology - size - arm length ratio - banding pattern
Oxidized hemoglobin precipiated within RBCs
Proton gradient
Kidney - ears - eyes
Karyotyping

24. What ribosomes do prokaryotes have
Unmethylated - newly synthesized - HNPCC
GTP hydrolysis - initiation factors assemble 40S ribosomal subunit with initiator tRNA and are released with mRNA and ribosomal subunit assemble with the complex
30 - 50 - 70
Inc glucagon - inc cAMP - inc PKA

25. What are the symptoms of vit A excess
Athralgias - fatigue - headaches - skin changes - sore throat - alopecia
Pyruvate to oxaloacetate (3C to 4C)
TRNA
ATP

26. In addition to fructose and galactose - what sugards should be excluded from the diets of patients with disorders of fructose or galactose metabolism
Progressive hreditary nephritis and deafness - associated with occular disturbances - due to abnl type IV collagen - usually x- linked recessive
Sucrose = glucose + fructose - lactose = glucose + galactose
Coenzyme A - lipoamide
Mutated dystrophin gene - less severe - adolescence

27. What is dominant negative mutation and give an example
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
Lack of tyrosinase (no melanin) AR ordefective tyrosine transporters (less tyrosine) - can results in lack of migration of NC cells
Removal of N or C termal propeptides from zymogens to generate mature proteins
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

28. Describe the structure of cilia
9+2 arrangement of microtubules
Ketone - methyl
Stored ATP - creatine phosphate - anaerobic glycolysis
B100 and E

29. What are the clinical features of I cell diesase
Coarse facial features - clouded corneas - restricted joint movements - high plasma levels of lysosomal enzymes - often fatal in childhood
Adenosine to inosine
Initiate chains
Alcohol version of glucose - can trap glucose in cell - aldose reductase

30. What apolipoprotein is on LDL
B100
Medial dorsal nucleus of thalamus - mamillary bodies
O- oligosaccharaides
Mediates chylomicron secretion

31. In eukaryotes - What does RNA poly I make
FAP
RRNA
Fabrys - alpha galactosidase A - ceramide trihexoside - XR
Inc intake of ketogenic nutrients - high in fact content or inc lysine or leucine

32. What does lactase deficiency cause
Many generations - both male and female affected - often pleiotropic - can present clinically after puberty
Tryptophan
Loss of brush border enzyme causing bloating - cramps - osmotic diarrhea
Absence of galactose 1 phosphate uridyltransferase - accumulation of toxic substances leads to failure to thrive - jaundice - hepatomegaly - infantile cataracts - mental retardation

33. What is the rate determining enzyme (RDE) of glycolysis
Phosphofructokinase 1
Tall with long extremeties - pectus excavatum - hyperextensive joints - arachnodactyly
SnRNPs
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

34. What enzyme esterifies 2/3 of plasma cholesterol
Type II
Oxidizes substrate
Inhibits acetaldehyde dehydrogenase and contributes to hangover symptoms
LCAT (lecithin cholesterol acyltransferase)

35. For eukaryotes - Where does replication begin?
Reads usual codon but inserts wrong AA
Oxidative and nonoxidative - no ATP produced or used
Males are infertile due to bilateral absence of vas deferens
Consesus sequenec of base pairs

36. Which type of chromatin is condensed - transcriptionally inactive - sterically inaccessible?
Aldolase B - AR - fructose 1P accumulates causing a dec in availabel phosphate which inhibts glycogenolysis and gluconeogenesis leading to hypoglycemia - cirrhosis - jaundice and vomiting
Proline and glycine (non glycosylated forms)
RER
Heterochromatin = HighlyCondensed

37. What does a decrease in decrease in NADPH lead to and why
Meiotic nondisjunction of homologous chromosomes (associated with advanced maternal age) leading to trisomy 21
APRT + PRPP
Phenylalanine hydroxylase
Poor defense from oxidizing agents - fava beans - sulfonamides - primaquine - antituberclosis drugs leadig to hemolytic anemia.

38. Pts with albinism are at inc risk For what cancer
P2 +2pq+ = 1
Skin
Alcohol version of glucose - can trap glucose in cell - aldose reductase
APC on chromosome 5

39. What is the initial transcript called and What is the capped and tailed transcript called
Initial is heterogenous nuclear RNA - the capped and tailed is called mRNA
F16BP
Riboflavin - cofactor in oxidation and reduction (FAD and FMN are derived from riboflavin)
B6

40. What amino acid makes up most of the octamer
Mental retardation - growth retardation - seizures - fair skin - eczema - musty body odor
Dec AFP - inc betahCGH - dec estradiol - inc inhibin - inc nuchal translucency on US
Lysine and arginine
B-100 - CII and E

41. How many ATP are produced by anearobic glycolysis per molecule of glucose
MEN - 2A and 2B with ret gene
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)
Never go to G0 - divide rapidly with a short G1 - bone marrow - gut epi - skin - hair follicles
Two

42. What does inc phenylalanine lead to...
Von Gierke's - Pompe - Cori - McArdle
Glycogenolysis to form glucose
Phenylketones in urine
Catabolic processes to carry reducing equivalents away as NADH

43. What happens do glycogen in skeletal muscle during exercise
Glycogenolysis to form glucose
SnRNPs
Lactate
Impaired glucose breakdown leading to ATP depletion; highly affected aerobic tissues like brain and heart affected first

44. What converts DOPA to dopamine
Degredation of TG circulating in chylomicrons and VLDLs
Dopa decarboxylase
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
Carnitine shuttle - acyl - coa from cyto to mito

45. What is RNAi used for
Phosphofructokinase 1
Breaks down acyl - coa to acetyl coa groups in mito
DsRNA promotes degradation of target mRNA knocking down gene expression
Malabsorption (sprue - enteritis) lack of intrinsic factor from pernicious anemia - gastric bypass surgery or absence of terminal ileum as in Crohns

46. Which anticancer drugs work on microtubules
Animal products - synthesized only by microorganisms - large reserve pool - mainly in liver
Vincritsine/vinblastine
AR
30 - 50 - 70

47. What is the composition of urea and where do each part derive from
Nissl body - enzyme and NTs
Fabrys - alpha galactosidase A - ceramide trihexoside - XR
NH2-(C=O) - NH2 one NH2 from ammonia the C=O from CO2 - and the other NH2 from aspartate
Inhibits the Na/K pump by binding the K side

48. What enzyme results in classic galactosemia and What is the clinical
Absence of galactose 1 phosphate uridyltransferase - accumulation of toxic substances leads to failure to thrive - jaundice - hepatomegaly - infantile cataracts - mental retardation
Breaks down acyl - coa to acetyl coa groups in mito
Semiconservative - continuous and discontinuous strands (okazaki fragments)
Backup of substrate (pyruvate and alanine) resulting in lactic acidosis - congenital or acquired from thiamine def in EtOH - neuro defects

49. Which are the basic amino acids
Antioxidant - constituent of visual pigment - essential for nl differntiation of epithelial cells into specialized tissue (pancreatic cells - mucus secreting cells) used to treat measles
Diphyllobothrium latum
Arg - lys - his - arg is most basic - has has no charge at body pH
Liver - ovaries - seminal vesicles

50. What is the Name and fxn of vit B5
Mutated dystrophin gene - less severe - adolescence
5' of the incoming nucleotide
Pantothenate - essential component of CoA - a cofactor for acyl transfers and fatty acid synthase
ATP