B6 Why alcoholics may not have inc LFTs

Enzymes Flashcards by Sahaja Parsa

Reversibly inhibits IMP dehydrogenase

Mycophenolate Mofetil

Ribavirin

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inhibits dihydroorotate
dehydrogenase

Leflunomide

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inhibit dihydrofolate
reductase

Methotrexate (MTX), trimethoprim (TMP),
and pyrimethamine:

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inhibits
thymidylate synthase

5-fl orouracil (5-FU) and its prodrug
capecitabine: form 5-F-dUMP, which inhibits
thymidylate synthase

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inhibit inosine
monophosphate dehydrogenase - use?

Mycophenolate - used for lupus nephritis

Ribavirin - Hep C

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inhibits ribonucleotide
reductase - use? SE/

Hydroxyurea

Use - SCD, Myeloproliferative disorders (PCV, CML)

SE - megaloblastic anemia,

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Location and use of CPS I v CPS II

CPS 1 - mitochondria
CO2 + NH3 + ATP –> Carbamoyl PO4
Urea cycle 1st step

CPS 2 - cytosol
Glutamine + CO2 + ATP –> Carbamoyl PO4 in pyrimidine base production

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Adenosine Deaminase def - Dz, MoI?

SCID - AR

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HGPRT def

Lesch Nyhan -

Hyperuricemia Gout Pissed off (aggression, self-mutilation) Retardation (intellectual disability) DysTonia

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DNA Helicase

Bloom Syndrome

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inhibits RNA polymerase II. Causes severe hepatotoxicity if ingested

α-amanitin, found in Amanita phalloides (death cap mushrooms

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inhibits RNA polymerase in both prokaryotes and eukaryotes.

Actinomycin D,

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inhibits DNA-dependent RNA polymerase in prokaryotes.

Rifampin

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N-acetylglucosaminyl-1-phosphotransferase

I-cell disease (inclusion cell disease/mucolipidosis type II)—inherited lysosomal storage disorder

coarse facial features, gingival hyperplasia, clouded corneas, restricted joint movements, claw hand deformities, kyphoscoliosis, and high plasma levels of lysosomal enzymes. O

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myotonin protein kinase

Myotonic dystrophy

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Cofactor of transketolase, which pathway?

HMP shunt

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Cofactor in ALT/AST

Why alcoholics may not have inc LFTs

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3 rxns that need B7 as cofactor

Pyruvate carboxylase: pyruvate (3C)
–> oxaloacetate (4C)
Acetyl-CoA carboxylase: acetyl-CoA (2C)
–> malonyl-CoA (3C)
Propionyl-CoA carboxylase: propionyl-CoA
(3C) –> methylmalonyl-CoA (4C)

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cofactor for dopamine
β-hydroxylase

Vitamin C

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(+)’d by epoxide reductase

Vitamin K

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(-) alcohol DH

Fomepizole

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blocks acetaldehyde dehydrogenase

Disulfiram

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Neurologic defects, lactic acidosis, inc serum alanine starting in infancy

Pyr DH complex def

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most common human enzyme deficiency

G6PD def

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MoI of G6PD def

XLR

fructokinase sx

fructose appears in blood and urine.

hypoglycemia, jaundice, cirrhosis, vomiting.

aldolase B

isolated infantile cataracts.

galactokinase def

galactose-1-phosphate uridyltransferase

Damage is caused by accumulation of toxic substances (including galactitol, which accumulates in the lens of the eye). Symptoms develop when infant begins feeding (lactose present in breast milk and routine formula) and include failure to thrive, jaundice, hepatomegaly, infantile cataracts, intellectual disability + kidney sx - amino aciduria, hyperchloremic metabolic acidosis

aldose reductase located where?

Lens has primarily aldose reductase. Retina, Kidneys, and Schwann cells have only aldose reductase

Which organs have both aldose reductase and sorbitol DH?

Liver, Ovaries, seminal vesicles

Cofactor for aldose reductase / sorbitol DH?

a) NADPH b) NAD+

Ornithine transcarbamylase deficiency - MoI, sx

inc orotic acid in blood and urine, dec BUN, symptoms of hyperammonemia

Homogentisate oxidase

Alkaptonuria Autosomal recessive. Usually benign. Findings: bluish-black connective tissue, ear cartilage, and sclerae (ochronosis); urine turns black on prolonged exposure to air. May have debilitating arthralgias (homogentisic acid toxic to cartilage).

Tyrosinase

Albinism

Phenylalanine hydroxylase

PKU

branched-chain α-ketoacid dehydrogenase

Maple syrup urine disease vomiting, poor feeding, urine smells like maple syrup/burnt sugar. Causes severe CNS defects, intellectual disability, death.

propionylCoA carboxylase - sx?

Propionic acidemia poor feeding, vomiting, hypotonia, anion gap metabolic acidosis, hepatomegaly, seizures.

Glucose 6 Phosphatase - sx?

Von Gierke Severe fasting hypoglycemia, --\> inc Glycogen in liver and kidneys, inc blood lactate, triglycerides, uric acid (Gout), and hepatomegaly, renomegaly. amino acid competes for same transporter as glucose, hence the inc in uric acid.

Lysosomal acid α-1,4glucosidase - dz?

Pompe Cardiomegaly, hypertrophic cardiomyopathy, hypotonia, exercise intolerance

α-1,6-glucosidase

Cori disease (type III)

Skeletal muscle glycogen phosphorylase

McArdle disease (type V)

HeXosaminidase A

Tay-Sachs disease

α-galactosidase A

Fabry disease

Arylsulfatase A

Metachromatic leukodystrophy

Galactocerebrosidase (galactosylceramidase)

Krabbe disease

Glucocerebrosidase (β-glucosidase)

Gaucher disease

Sphingomyelinase

Niemann Pick disease

α-l-iduronidase

Hurler

Iduronate-2-sulfatase

Hunter syndrome

Medium-chain acyl-CoA dehydrogenase deficiency

— ability to break down fatty acids into acetyl-CoA --\> accumulation of fatty acyl carnitines in the blood with hypoketotic hypoglycemia. Causes vomiting, lethargy, seizures, coma, liver dysfunction, hyperammonemia.

HMG-CoA synthase and lyase

ketone production

HMG-CoA reductase

chol synthesis

Lipoprotein lipase Cofactor

C-II

Activates LCAT

A-I

Hepatic lipase

Degrades TGs remaining in IDL

Hormone-sensitive lipase

Degrades TGs stored in adipocytes.

PCSK9 fxn? drug that targets it?

degrades LDL receptor Alirocumab, evolocumab

Lipoprotein lipase or apolipoprotein C-II deficiency - sx?

Type I dyslipidemia - Hyperchylomicronemia Pancreatitis, hepatosplenomegaly, and eruptive/pruritic xanthomas

Defect of NADPH oxidase how to test for it?

Chronic granulomatous disease ## Footnote ``` Abnormal dihydrorhodamine (flow cytometry) test ( dec green fluorescence). Nitroblue tetrazolium dye reduction test (obsolete) fails to turn blue. ``` no blue, no green for CGD

reversibly (-) IMP DH - use? SE/

Mycophenolate Mofetil use - lupus nephritis ## Footnote SE/ GI upset, pancytopenia,hypertension, hyperglycemia. Associated with invasive CMV infection.

Urease + organisms predisposes you to what type of stones

Proteus, Cryptococcus, H pylori, Ureaplasma, Nocardia, Klebsiella, S epidermidis, S saprophyticus. struvite stones (ammonium magnesium phosphate)

Patients with NADPH def have susceptibility to ________ positive organisms List them

Catalase + G+ = Nocardia, Listeria, Staphylococci, G- = Pseudomonas, E coli, Serratia, B cepacia, H pylori. Fungi = Aspergillus, Candida,

IgA protease secreted by ?

S pneumoniae, H influenzae type b, and Neisseria (SHiN).

Adding deoxyribonuclease degrades naked DNA, preventing ______ (this bacterial process)

Transformation

List 3 bacterial toxins that overactivate adenylate cyclase

``` ETEC heat labile toxin Cholera toxin (by (-) Gi) Bordetella pertussis (disable Gi) ```

Bact toxin that mimics adenylate cyclase

Bacillus anthracis

In an AB toxin, the active a component is usually an ___ \_\_\_\_\_\_\_\_\_

ADP ribosyltransferases

bacterial toxin that is a lecithinase/phopholipase

Clostridium perfringens alpha toxin

Which staphylococci are coagulase + vs -

+ = S. aureus - = S. saprophyticus, S. epidermidis

Which G- diplococci produces maltose acid?

N. meningiditis N. gon and Moraxella are neg for maltose acide

Which G- bacilli ferment lactose

Fast - E. coli, Klebsiella, Enterobacter Slow - Citrobacter, Serratia

Of the bacilli non lactose fermenters, which produces oxidase

Pseudomonas

Which G- bact produce Phospholipase C

Pseudomonas - breaks down cell membranes

Which microorganism leads to (-)'n of tyrosinase?

Tinea versicolor (hypo/hyperpigmentation) Malassezia furfur

Naked nucleic acids of ⊝ strand ssRNA and dsRNA viruses are not infectious. They require \_\_\_\_\_\_\_\_contained in the complete virion.

polymerases

DNA virus with its own reverse transcriptase

Hepadna (Hep B)

-ssRNA virus that produces neuraminidase

Influenza (Orthomyxo) Parainfluenza (Paramyxo) - croup

Antibiotics that binds transpeptidases

All Beta lactams - bind penicillin binding proteins (transpeptidases)

inhibitor of renal dehydropeptidase I, given with carbapenems

Cilastatin

Rx that Inhibit dihydropteroate synthase

Sulfonamides, Dapsone

Inhibit prokaryotic enzymes topoisomerase II (DNA gyrase) and topoisomerase IV.

Flouroquinolones

Inhibit DNA-dependent RNA polymerase.

Rifampin, Rifabutin

Rx that dec carbohydrate polymerization of mycobacterium cell wall blocking arabinosyltransferase.

Ethambutol

Inhibits DNA and RNA biosynthesis by conversion to 5-fluorouracil by cytosine deaminase.

Flucytosine

Inhibits the fungal enzyme squalene epoxidase.

Terbinafin

Inhibit influenza neuraminidase

Oseltamivir, Zanamivir

Acyclovir, etc are monophosphorylated by ?

Monophosphorylated by HSV/VZV thymidine kinase and not phosphorylated in uninfected cells --\> few adverse effects.

Viral DNA/RNA polymerase inhibitor and HIV reverse transcriptase inhibitor.

Foscarnet

inhibits viral DNA polymerase

Ganciclovir and Cidofovir

Pyruvate DH def leads to an increase of what in the blood?

lactic acid serum alanine

Sofosbuvir and Dasabuvir work on what enzyme?

Inhibits NS5B, an RNA-dependent RNA polymerase

Grazoprevir ,Simeprevir (-) what enzyme

Inhibits NS3/4A, a viral protease, preventing viral replication.

Enzyme in the 3rd phase of wound healing - needs ______ to function

Collagenases - break down type III collagen, need zinc to function

Granulomas are associated with hypercalcemia bc of ?

Inc 1alpha hydroxylase mediate vitamin D activation in macrophages

In invasive carcinomas, cells have invaded basement membrane using

using collagenases and hydrolases (metalloproteinases) cell-cell contacts lost by inactivation of E-cadherin

regenerates AchE

pralidoxime

Phentolamine is used to patients on _______ \_\_\_\_\_\_ who eat meat and cheese

MAO inhibitors