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Flashcards in Biochem Deck (48):
1

α-amanitin

-found in death cap mushroom.
-inhibits RNA pol 2 (makes mRNA).
-hepatotoxic.

2

P-bodies

-mRNA quality control.
-cytoplasmic.
-contain exonucleases, decapping enzymes, and microRNAs
-mRNAs may be stored here for future translation.

3

spliceosomal snRNPs

-Abs against these = anti-smith Abs
-specific for SLE

4

Trimming

-post-translational modification.
-Removal of N- or C-terminal propeptides from zymogen to generate mature protein (e.g., trypsinogen to trypsin).

5

Ingredients to make Niacin (B3)

Tryptophan
B2 (riboflavin)
B6 (pyridoxine)

6

Base excision repair

1-glycosylase = strips off base
2-endonuclease = cleaves 5' end
3-lyase = cleaves 3' end
4-DNA pol
5-ligase

7

Enhancers and silencers (of gene expression)

Variable locations

8

COP1

Retrograde
-Golgi => Golgi
-Golgi => ER

9

COP2

Anterograde
-Golgi => Golgi
-ER => Golgi

10

Ribozyme (rRNA)

Catalyzes peptide bond formation btwn amino acids

11

Ouabain

Inhibits Na/K ATPase by binding to K site.

12

Type 3 Cartilage

Reticulin:
-blood vessels
-uterus
-fetal tissue
-granulation tissue

13

Problems forming triple helix in RER (collagen).

Osteogenesis imperfecta

14

Problems cross-linking collagen (lysyl oxidase)

Ehlers Danlos

15

Menkes Disease

-CT disease
-impaired copper absorption and transport.
-leads to dec. lysyl oxidase activity (cross links collagen)
-brittle, “kinky” hair, growth retardation and hypotonia.

16

Pleiotropy

One gene contributes to multiple phenotypic effects.
ie. PKU

17

Dominant negative mutation

Exerts a dominant effect. A heterozygote produces a nonfunctional altered protein that also prevents the normal gene product from functioning.
-Mutation of a transcription factor in its allosteric site. Nonfunctioning mutant can still bind DNA, preventing wild-type transcription factor from binding.

18

McCune-Albright syndrome

-lethal if themutation is somatic, but survivable if mosaic.
-polyostotic fibrous dysplasia with cafe-au-lait skin
pigmentation and endocrinopathies.

19

Locus heterogeneity

Mutations at different loci can produce a similar
phenotype.
-ie. albinism

20

Allelic heterogeneity

Different mutations in the same locus produce the same phenotype.
-ie. beta-thal

21

Heteroplasmy

Presence of both normal and mutated mtDNA, resulting in variable expression in mitochondrial inherited disease.

22

Heterodisomy

meiosis 1 error

23

Isodisomy

meiosis 2 error

24

Prader-Willi & angelman
-which chromosome?

15
-or uniparental disomy. Inherit two methylated copies.

25

Hypophosphatemic rickets

Formerly known as vitamin D–resistant rickets. Inherited disorder resulting in  phosphate wasting at proximal
tubule. Results in rickets-like presentation.

26

Mitochondrial myopathies

rare disorders; often present with myopathy, lactic acidosis and CNS disease. 2° to failure in oxidative
phosphorylation. Muscle biopsy often shows “ragged red fibers.”

27

FAP
-which chromosome?

5
-5 letters in "polyp".

28

Osler-Weber-Rendu Syndrome

aka Hereditary hemorrhagic telangiectasia
-Inherited disorder of blood vessels.
-Findings: telangiectasia, recurrent epistaxis, skin discolorations, arteriovenous malformations (AVMs), GI bleeding, hematuria.

29

NF1
-which chrom?

17
-17 letters in “von Recklinghausen.”

30

NF2
-which chrom?

22
-NF2 = 22

31

VHL
-which chrom?

3
-VHL = 3 letters

32

Hardy Weinberg

The frequency of an X-linked recessive disease
in males = q and in females = q^2.

33

Cystic Fibrosis

-infertility in males due to abscence of vas deferens and therefore absent sperm.
-Tx of CF = N-acetylcysteine, dornase alfa

34

Duchenne MD

-Frameshift mutation
-Dilated cardiomyopathy = common cause of death.

35

Becker MD

-X-linked point mutation

36

Myotonic type 1 MD

-CTG trinuc. repeat in DMPK gene.
-abnormal expression of myotonin protein kinase.
-frontal balding, testicular atrophy, arrythmia.

37

Fragile X
-whats the trinuc?

CGG

38

Down's Syndrome

-Brushfield spots, gap btwn first 2 toes, hirschsprungs.
-meiotic nondisjunction, robertsonian translocation, mosaicism.
-First-trimester ultrasound commonly shows:
 nuchal translucency and hypoplastic nasal
bone; dec. PAPP-A, inc. b-hCG.
-Second-trimester quad screen shows:
 dec. α-fetoprotein, inc. b-hCG,  dec. estriol, inc.
 inhibin A.

39

Edwards syndrome

-micrognathia, low set ears, congenital heart disease, clenched hands,
-PAPP-A and b-HCG = both dec in 1st trimester.
-Quad screen: everything dec. (AFP, B-hCG, estriol, inhibin A).

40

Patau syndrome

-microphthalmia, microcephaly, cleft lip/palate, holoprosencephaly, polydactyly, congenital heart disease.
-dec. b-hcg & PAPP-A.
-inc. nuchal translucency.

41

Cri-du-chat syndrome

-5p microdeletion
-microcephaly, intellectual disability, high-pitched
crying/mewing, epicanthal folds, cardiac abnormalities (VSD).

42

Williams syndrome

-7q microdeletion (incl. elastin gene).
-“elfin” facies, intellectual disability, hypercalcemia ( sensitivity to vitamin D), well-developed verbal skills, extreme friendliness with strangers, cardiovascular problems.

43

Vitamin A

treates measles & AML-M3

44

B2 deficiency

Cheilosis, Corneal vascularization.

45

Vitamin C: uses

-Reduces ferric to ferrous
-hydroxylation of lysine & proline
-dopamine => NE

46

Vitamin E

-can enhance anti-coag effects of warfarin. May lead to bleeding problems.

47

hyPOphosphorylated Rb

-No passage from G1 to S.
-Cell stopped.
-Abnormal cell.

48

hyPERphosphorylatd Rb

-inactive
-Cell can progress
-everything is normal