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Flashcards in Other Deck (109):
1

N-formylmethionine (fMet) role

1. Initiation amino acid in prokaryotes
2. Neutrophil chemotaxis

2

Introns can contain

miRNA genes

3

Cistinuria - treatment

Urinary alkalization (potassium citrate, acetazolamide), chelation agents (penicillamin)

4

Golgi apparatus function

1. Modifies N-oligosaccharides on Aspargine
2. Adds O-Oligosacch on SERINE + THREONINE
3. Adds Mannose-6-p

5

Procollagen bonds

hydrogen + disulfide

6

protein synthesis direction

N-terminus to C

7

intros sequence

GU....AG

8

tRNA activates energy

1. charging - ATP
2. initiation pr synthesis - GTP
3. ribosomes translocation - GTP

9

Pyridoxine function

1. transamination
2. decarboxylation
3. glycogen phosphorylase
CYSTATHIONE, heme, niacin, HISTAMINE, SERETONIN,, epinephrin, norepin, dopamine, GABA`

10

Tuberous scleoris - phenotype expression features

INCOMPLETE PENETRANCE
variable expression

11

Duchenne gait, MCC of death

1. waddling gait
2. Dilated cardiomyopathy

12

Pompe disease findings

1. Cardiomyopathy
2. hypertr cardiomyopathy
3. exercie intolerance
4. systemic findings leading to early death

13

HMG-coa reductase regulators

+ insulin, T4
- Glucagon, cholesterol

14

ATP production - pathways

malate-aspartate --> 32
Glycerol-3-P --> 30
Anaerobic --> 2

15

NADPH is used in

1. anabolic (not ketones)
2. P450
3. Respiratory burst
4. Glutathione reductase

16

Pyruvate to lactate - major pathway in which tissues

1. RBCs 2. testicles 3. leukocytes
4. lens 5. kidney medulla 6. cornea

17

inhibitors of every step in REDOX

1. complex 1 --> rotenone
2. complex 2 --> antimycin A
3. complex 4 --> cyanide, CO
4. complex 5 --> oligomycin
5. uncoupling agents --> dinitrophenol, aspirin, thermogenein

18

gluconeogenesis tissues

liver
intestine
kidney

19

fatty acids/gluconeogenesis

even chain --> cannot produce since only acetyl-coa
odd chain --> yield one propionyl-coa --> succinyl coa --> glucose

20

sites of HM shunts (organs)

fatty acid or steroid synthesis
1. RBCs
2. lactating mammary glands
3. liver
4. adrenal

21

Tissue with sorbitol dehydrogenase

1. ovaries
2. seminal vesicles
3. liver

22

Tissue without sorbitol dehydrogenase

1. scwann
2. retina
3. kindey
4. lens

23

essential glucogenic ketogenic aminoacids

1. phenylalanine
2. tryptophan
3. threonine
4. isoleucine

24

hyperammonemia treatment

1. limit protein
2. lactulose
3. Neomycin + rifamixin
4. Phenylbutyrate or Benzoate --> bind aminoacid + lead to excretion

25

mechanism of hypoglycemia in acyl-coa dehydrogenase deficiency

acyl-coa is a + allosteric regulator of pyruvate carboxylase

26

types of ketone bodies (+ tests)

acetone
acetoacetate
β-hydroxybutyrate (not in urine)

27

MC heart defect in Turner (and ausculation)

bicuspid aortic valve (20-30%) --> early systolic, high frequency click over the riht second intespace
(other heart defect is coartraction 3-10%)

28

familiar hypercholesterolemia - type of mutation

frameshift

29

Syndromes with shortened telomeres

syndromes with premature aging (eg. Bloom syndrome)

30

GAA in frataxin --> ...

decreased translation (NOT TRUNCATED)

31

The low of segregation

Mendel's first law:
gametogenesis within parent organism results in separation of paired alleles so that each offspring inherits only half of each parent's genetic composition

32

Turner - area of coartraction

Preductal

33

CF - infertility

inadequate mesonephric duct development

34

Down syndrom - nondisjunction during

anaph 1 or 2

35

out of frame vs in frame mutation

out of frame --> premature termination
in frame --> maintains the reading

36

RNA polynerase I vs II vs III according to production

I --> 18S, 5.8S & 28S ribosomal RNA (first 45 that divided)
II --> mRNA, miRNA, snRNA
III --> tRNA, 5S ribosomal RNA (essentail for 60S subunit)

37

presenilin genes ch

presenilin 1 --> ch 14
presenilin 2 --> ch 1

38

CF vs Primary ciliary dyskinesia according to nasal polyps, digital clubbing

both have

39

palindromic sequence in DNA

reading 5--> 3 in one strand is the same as 5-->3 to the other

40

Lyonization

X-inactivation
Methylated DNA
deacetylated histones

41

Risk factors for molar pregnancy

1. maternal age
2. prior molar pregnancy
3. infertility
4. prior miscarriage

42

MEN 1 ch
p53 ch

11
17

43

pheo vs renal ca in VHL

renal is more common

44

epistasis?

the allele of one gen affects tje phenotypic expression of alleles in another gene

45

primary amenorrhea

absence of menses by age 15 in someone who has normal growth + secondary sexual characteristics or absence of menses by age 13 in girls without 2ry sexual characteristics

46

TATA box location
CAAT box location

25 bases upstream from the beginning of the coding strand (aka Hogness box)
70-80 bases upstream from the beginning of the coding strand

47

protein kinase regulates the activity of its target proteins by

phosphorylating threonine + serine residues

48

promoter in prokaryotes

Pribnow box (-35)

49

patau vs Down vs edwards according to GI manifestations

Down --> Hirschsprung, duodenal atresia
Patau --> omphalocele
Edwards --> Meckel's, diverticulim

50

mechanism of decreased expression of huntingtin protein in Huntington disease

hypo acetylation of histones

51

beside the others, DOWN also increases the risk for

imperofrate anus, tracheoesophageal fistula, celiac disease

52

Down syndrome - endocrinology + rhematology

1. endocrinology: hypothyroidism, DM1, obesity
2. Rhematology: Antlantoaxial instability

53

chorionic villus sampling can be performed at ... (when)

10-14 weeks gestation (it has risks)

54

CFTR modulating medications that that promote its transportation at membrane and enhance its action

1. Lumacaftor (transportation)
2. Ivacaftor (enchantment)
IMPROVE FEV + DECREASED PULMONARY EXACERBATIONS

55

other mutations that cause CF

1. mutation that impairs ATP binding
2. mutation that decreased production of normal CFTR (milder)
3. mutation that impairs CL- conduction through CFTR
4. mutation that cause premature termination o the protein (nonsense, frameshift) (usually seen in Askenazi)

56

polycistronic mRNA

found in bacteria --> multiple open reading frames --> translated into several proteins
(not in human: MONOCISTRONIC mRNA --> only 1 protein)

57

MCC of hair loss in both men and females / mode of inheritance

androgenic alopecia --> polygenic (both hormonal + genetic factors) (esp X, Y, short 20 chromosome)

58

eukariotic cells initiation of translation

- AUG
- Kozak consensus

59

viral interference?

one virus inhibits replication and/or release of a 2nd virus that is infecting the same cell

60

MCCC sex chrom abnormality in females? / presentation

47 XXX --> usually diagnosed incidentally as the carriers are NORMAL

61

reverse transcriptase of human cells / function / structure

telomerase (RNA depended DNA polymerase
--> Adds TTAGGG repeats to the 3' end of chromosomes
--> composed of 2 main subunits: a. telomerase reverse transcriptase subunit b. telomerase RNA compoment

62

Vaginal adenosis

replacement of vaginal squamous epithelium with glandular columnar epithelium. it occurs in female children of women exposed to DES during pregnancy. It is a precursor of clear cell adenocarcimona of vagina

63

Methanol induced blindness

methanol --> formic acid (alcohol dehydrogenase)

64

Renal ammoniogenesesis?

renal tubular epithelial cells: glutamine --> glutamate + ammonium + HCO3 (in response to acidosis)

65

1. characteristic of ANA in RA
2. citrullination

1. IgM
2. tissue inflammation --> argining residues in proteins such as vimentin to citrulline --> altered shape of antigen --> immune response generation

66

SnRNAs are synthesized by
miRNAs are synthesized by

both by RNA pol 2

67

MAO enzyme - origin

mitochondria

68

PCR vs rtPCR according to template

PCR: DNA
rtPCR: cDNA

69

Bloom syndrome

rare AR --> BLM gene (helicase) mutation) --> growth retardation, facial anomalies, photosensitivity skin rash, immunodeficiency (due to ch instability + breakage)

70

nuclear and mit proteins synthesis location

nuclear --> RER
mit --> cytoplasm

71

fructose metabolism abnormalities - 1. breast milk 2. starch

1. no problem because breast milk contains lactose (gal + glu) and maltose (glu + glu) (formula has sucrose)
it does not contain lactose
2. no problem -> starch has only glu

72

McArdle disease - how to improve symptoms

consume sugar before exercise

73

biotin deficiency - ph?

lactic acidosis

74

rate-limiting step in the synthesis of catecholamines

tyrosine hydroxylase (tyrosine --> DOPA)

75

raw eggs white causes biotin depletion due to

high levels of biotin-binding avidin

76

copper reduction test?

detect reducing sugar (fructose, glucose, galactose) --> non specificg
(urine dipsstick --> specific specific for sugar)

77

the elastic properties of elastin are due to

interchain cross-links involving lysine (lysil oxidase) (desmosine cross links)

78

neurofibrosarcomas

malignant peripheral nerve sheath tumors that arise from neurofibromas

79

lead poisoning - type of protoporphirin

zinc protoporphirin (instead of Fe2+)

80

Dopamine hydroxylase deficiency

rare --> dysautonomia (ptosis, orthostatic hypertension, hypoglycemia, hyponatremia)

81

phenylketonuria - brain hypopigmentation

of catecholaminergic locations:
1. locus ceruleus
2. substantia nigra
3. vagal nucleus dorsalis

82

enzyme with increased activity in Lench-Nuhan syndrome

PRPP amidotransferase

83

carotene is a precursor to

vit A

84

degradation of proteins - location

nuclear + cytoplasmic --> proteosome
extracellular --> lysosomes

85

miRNA - mechanism

transcription in nucleus (pre mirna) - double strand --> cleaved into short RNA helix by ribonuclease protein (DICER) --> seperation of strands --> bind mRNA --> exact match causes mRNA degradation, partial match causes transnational represion by preventing ribosome + transcription factors to bind (posttranscriptional gene silencing)

86

pellagra mediated dementia

due to neuronal degeneration in the brain + spinal cord, with lesions similar to those in B12 deficiency

87

Arginase deficiency in urea cycle - manifestation/treatment

progressive diplegia, growth delay, abnormal movements (mild or no hyperammonia)
treatment: arginine-free, low-protein diet

88

protein structure - bonds

1ry --> covalent
2ry --> hydrogen
3ry --> ionic, udrophobic, hydrogen, disulfide

89

Tetrahydrobiopterin (BH4)?

cofactor used by hydroxylase enzymes in the synthesis of:
1. Tyrosine
2. Dopamine
3. Seretonin
4. NO

90

Methoglobinemia - skin

cyanosis

91

Methylmalonic acidema?

methylmalonyl-Coa mutase (AR) --> lethargy, vomiting, tachpnea
--> hyperammonemia, ketotic hypoglycemia, met acidosis
--> elevated methylmalonic acid + propionic acid

92

essential fructosuria - alternative pathway for fructose metabolsim

fructose --> fructose 6-P (hexokinase) --> enter glycolysis

93

Glutamate - glutamine cycle

in the astrocytes: Glutamate + NH3 --> Glutamine (glutamine synthetase)
in neurons: Glutamine --> glutamate (Glutaminase) --> releasing

94

excess ammonia (eg. cirrhosis) - what happen in astrocytes?

increased glutamine production --> increased intracellular osm --> astrocyte swelling --> impaired glutamine release --> decreased glutamate in neurons --> disruption of excitatory neurotransmission

95

leptin action

acts on the arcuate nucleus of hypothalamus --> inhibit production of neuropeptide Y (decreasing apetite)
also stimulate the production of POMC at the same location

96

acquired obesity - leptin

high leptin --> receptor desensitisation

97

Lac operon - genes and their function

z gene --> β-galactosidase --> lctose to glucose + galactose
y gene --> permease --> transmembrane enzyme --> increases permeability of the cell to lactose
a gene --> β-galactoside transacetylase (unnecessary for lactose metabolism to E-coli
(LAC operon also has promoter region + operator region + regulatory gene (repressor protein))

98

cyanide poisoning - presentation

reddish skin discoloration, tachypnea, headache, tachycardia, nausea/vomiting, confusion, weaknes --> seirzures + cardiovascular collapse
- lactic acidosis, narrowing of venous arterial PO2 gradient

99

Hers disease

liver glycogen phosphorylase deficiency --> hypoglycemia, ketosis, hepatomegaly

100

Spinal muscular atrophy - genes

mutation in Survival motor neuron (SMN1) gene, which encodes a protein involved in assembly of snRNPs in LMN

101

cherry red macula spot in severel sphingolipodosis - mechanism

loss of retinal transparency due to ganglioside buildup in ganglion cells
the center of fovea lacks ganglion cells so the underlying choroid transmits its red color

102

hormone that is increased in low BH4 mediated hyperphenylanemia

prolactin (low dopamine production)
- even if phenylanine restriction (because BH4 is also cofactor of tyrosine hydroxylase)

103

Lynch syndrome - genes (and their function)

mutation of methylation of:
1. MSH2 (code MutS) --> detects mismatch
2. MLH1 (code MutL) --> after detection --> slides along DNA

104

amatoxin - symptoms, diagnosis

6-24h after ingestion --> abdominal pain, vomiting, severe cholera-like diarrhea that may contain blood + mucus, acute hepatic + renal faulre
diagnosis: urine test

105

enzyme that contribute to ketongensis + maintains glucose level in fasting

hormone sensitive lipase -->
a. glycerol to glucose (glycerol kinase)
b. Fatty acids to ketone bodies

106

maturity onset diabetes of the young - presentation

mild nonprogressive hypoglycemia that often worsens with pregnancy-induced insulin resistance --> if homozygous --> fetal growth retardation + severe hypoglycemia in birth

107

Ricin?

from castor oil plant Rinicus commus --> potent toxin that inhibits protein synthesis by cleaving the rRNA component of the eukaryotic 60S subunit

108

synchronisation of of glycogen degradation with skeletal muscle contraction occurs due to

release of sarcoplasimic calcium releasing --> phosphorylase kinase --> glycogen phosphorylase --> increased glyocogenolysis

109

liver - ketone using for enegy

cannot because it lacks succinyl coa acetoacetate CoA tranferae (thiophorase) which is required to convert acetoacetate to acetoacetyl coa