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Flashcards in Phase A/ Biochem Deck (54):
1

Why do mycoplasma and chlamydia stain poorly?

no peptidoglycan

2

What mediates endotoxin activity of LPS?

Lipid A

3

which bacteria form spores?

gram + only

4

polyenes with broad antifungal activity
bind to membrane sterols (ergosterol) and causes membrane disruption by acting as a pore

amphotericin B
nystatin
Use (amphotericin B): invasive fungal infections -> Candida, Aspergillus, Cryptococcus,

5

prevent ergosterol synthesis by inhibition of 14-alpha-demethylase

"azoles"
voriconazole
itraconazole
fluconazole
terconazole

6

systemic imidazole antifungal that inhibits CYP3A4

ketoconazole
Many drug interactions
at high dose, inhibits adrenal steroid biosynthesis

7

antifungal that disrupts mitotic spindles and is used for hair, nails and skin infections

Griseofulvin

8

inhibits squalene epoxidase, causing decreased ergosterol and increased squalene (toxic to fungus)

terbinafine (Lamisil)*
buenafine
naftifine
tolnaftate (Tinactin)

9

inhibits synthesis of beta(1,3)-D-glucan

caspofungin*
micafungin
anidulafungin

10

converted to 5-FU in fungal cells and phosphorylated to 5-FdUMP to inhibit thymidylate synthase; also disrupts protein synthesis when incorporated in to RNA

flucytosine

11

antiviral agent resistance mechanism

mutation in viral thymidine kinase
viral nucleoside analogs require activation by viral thymidine kinase.

12

sources of acid in the blood

sulfuric acid -> dietary sulfate, s-containing amino acids
carbonic acid -> CO2 from TCA
lactic acid -> anaerobic glycolysis
pyruvic acid -> glycolysis
citric acid -> TCA & diet

13

what cells have high levels of carbonic anhydrase?

RBCs

14

charge of DNA
charge of histone

negative
positive (due to lysine & arginine)

15

histone not in nucleosome core

H1
(2A, 2B, H3, H4 all in nucleosome core)

16

highly condensed and transcriptionally inactive

heterochromatin

17

transcriptionally active

euchromatin

18

methylation here represses transcription

CpG islands

19

location of ETC

inner mitochondrial membrane
The cristae increase the SA of the IMM

20

purines

adenine
guanine

21

pyrimadines

cytosine
uracil
thymine

22

template for mRNA synthesis

sense strand

23

smooth ER in skeletal muscle

sarcoplasmic reticulum

24

site of lipid synthesis & is more abundant in cells which synthesize hormones

smooth ER

25

adds carbohydrates & lipids to proteins from RER

Golgi apparatus

26

protein structure characterized by large number of H-bonds

beta pleated sheet

27

synthesized from thiamine
chelates Mg2+ which then binds tightly to enzyme
Fxn: decarboxylation of alpha keto acids and utilization of pentose phosphates in Pentose Phosphate Pathway

TPP
thiamine pyrophosphate

28

coenzyme that bind to lysines in carboxylases

biotin

29

from panthothenate
forms thioesters with acyl groups

CoASH

30

from vit B6
reactive aldehyde that forms covalent intermediate with amino groups of Schiff bases

pyridoxal phosphate (PLP)

31

coenzyme from niacin & ATP

NAD+

32

bind irreversibly to active site on enzyme and inhibit it

suicide inhibitors

33

concentration of substrate to reach 1/2 Vmax

Km

34

regulatory protein of the Ca2+ ATPase of the ER

calmodulin
the Ca2+ ATPase is activated to pump calcium from the cytosol into the lumen of the ER when a rise in intracellular concentration causes calcium binding to calmodulin, followed by its dissociation from the transporter

35

cAMP-regulated chloride channel

CFTR

36

integral membrane receptors which recognize lysosomal enzymes in the Golgi

mannose 6-phosphate receptors

37

B3

niacin
NAD+

38

B2

riboflavin
FAD, FMN

39

B1

thiamine
TPP

40

B5

pantothenic acid
CoA

41

B6

pyridoxine
PLP

42

B7

biotin

43

B9

folate

44

B12

cobalamin

45

vit C

ascorbic acid

46

vitamin used to treat measles and AML (M3)
antioxidant
essential for normal differentiation of epithelial cells
visual pigments

vitamin A = retinol
Deficiency causes night blindness, dry, scaly skin, alopecia, keratomalacia, immune suppression.
Excess: arthralgia, scaly skin, alopecia, cerebral edema, pseudotumor cerebri, osteoporosis, hepatic abnormalities; TERATOGEN

47

cofactor for:
pyruvate dehydrogenase (glycolysis -> TCA)
alpha-ketoglutarate dehydrogenase (TCA)
transketolase (HMP shunt)
branched-chain ketoacid dehydrogenase

thiamine (B1)

Dx deficiency: increased RBC transketolase activity after giving B1

48

damage to medial dorsal nuclei of thalamus/mamillary bodies
confusion, ataxia, confabulation, personality change
permanent memory loss
vitamin B1 def

Wernicke-Korsakoff syndrome

49

causes beriberi

thiamine deficiency
dry beriberi: polyneuritis, symmetrical muscle wasting
wet beriberi: high output cardiac failure, edema

50

cofactor for redox reactions (ex: succinate dehydrogenase reaction in TCA)
cheilosis, corneal vascularization

riboflavin (B2)
FAD & FMN
"flav-o-flav has 2 gold teeth, smooth lips and drinks beri soda"

51

Diarrhea, Dementia, Dermatitis (3 D's)
Glossitis

niacin (B3)
pellagra

52

cofactor for acyl transfers (CoA) & fatty acid synthase

pantothenate (B5)
"pento"thenate

53

Cofactor for carboxylase reactions

Biotin

54

Coenzyme synthesized from niacin and ATP

NAD