Board Prep Biochem Flashcards
Homeobox genes
genes encoding for TRANSCRIPTION FACTORS crucial during embryologic development
Syndrome with mutated homeobox genes is Basal cell nevus syndrome
Uncoupling agents in the mitochondria
increase the permeability of the inner mitochondrial membrane and decrease the number of ATP per glucose
Decreased protons in the transmembrane space
Hepatic triglyceride lipase
breaks down triglycerides in intermediate density lipoproteins
Niemann-Pick disease
Autosomal recessive disease due to deficiency of sphingomyelinase (increased sphingomyelin)
Ashkenazi Jewish descent
hepatosplenomegaly differentiates from Tay-sachs
Ketone body synthesis disorder
Carnitine deficiency
urinary carnitine wasting
without carnitine, acyl-CoA is trapped in cytosol, disrupts beta-oxidation impairing ketone body synthesis
Organelles in which Vitamin C is a cofactor
vesicles (the hydroxylation of dopamine to norepinephrine) and the endoplasmic reticulum (hydroxylation of proline and lysine on preprocollagen)
Accumulation of NADH
several downstream effects in order to regenerate NAD+
lactic acidosis
inhibition of gluconeogenesis
increased fatty acid synthesis
What organelle participates in phase I and II detoxification
The Smooth Endoplasmic Reticulum (which is also responsible for synthesis of phospholipids, lipoproteins, and sterols)
Western blot
uses protein antibodies
Angelman’s syndrome
can be worded mutation on maternal chromosome 15
or uniparental disomy from the paternal 15
Cyanide on ETC
cells are only able to use glycolysis–> lactic acidosis
AMS, new onset seizures, hepatic failure, rhabdo(leading to renal failure)
flushed skin with tachy, tachypnea HTN –> opposite later
use Hydroxocobalamin for treatment
Gaucher disease
Beta-glucocerebrosidase deficiency
avascular necrosis of distal femur, osteopenia, hepatosplenomegaly, thrombocytopenia
accumulation of glucocerebroside
Ashkenazi Jewish descent
macrophages filled with lipids (wrinkled paper)
Krabbe disease
optic atrophy, seizures, and eventual death
globoid cells around the cytoplasm within the white matter (multinucleated macrophages with abundant cytoplasm)
deficiency of galactocerebrosidase
elevated galactocerebroside
Fabry’s disease
Alpha-galactosidase A deficiency
peripheral neuropathy and renal disease
Metachromatic leukodystrophy
Arylsulfatase A deficiency
demyelination of both central and peripheral nervous systems leading to ataxia and cognitive decline
Optic atrophy
Vitamin co factor for odd-chain fatty acid metabolism
Vitamin B12 is needed for the conversion of Methylmalonyl-CoA to Succinyl-CoA by Methylmalonyl-CoA mutase
Insulins role in glycogen synthesis
inactivates phosphorylase kinase by dephosphorylating it
inactivates glycogen phosphorylase a by desphosphorylation
activates UDP-glucose phosphorylase
Apolipoprotein B-100
the only apolipoprotein associated with LDL
binds the LDL receptor on the liver
facilitates trafficking of the LDL throughout the tissues in the body
Heteroplasmy
refers to the presence of both mutated and non-mutated mitochondrial DNA within the same cell, leading to differences in disease severity
Xeroderma pigmentosum
Autosomal recessive defective NER
Sarcoidosis
multisystem granulomatous disorder
noncaseating granulomas
young adults – bilateral hilar adenopathy, pulmonary reticular opacities, skin, join, eye lesions
reiculoendothelial system disease
vitamin D excess due to epitheliod macrophages
Substrate level phosphorylation
Cytosol: 1,3-bisphosphogylcerate to 3-phosphoglycerate; and PEP to pyruvate
Mitochondria (TCA): Succinyl-CoA to succinate
Homocystinuria
cysteine becomes an essential amino acid due to deficiency of enzyme that converts methionine to cysteine
GLUT 4 transporter
facilitated diffusion
Vitamin E deficiency
deficiency can lead to hemolytic anemia, muscle weakness, and neuro defects
Cystathionine synthase deficiency
elevated homocysteine
looks marfanoid-like
increased risk of strokes
LENSES displaced DOWNWARDS
Kwashiorkor
more commonly associated with hepatomegaly and anasarca
anorexia
Function of Apolipoprotein E
bind LDL receptor
Apolipoprotein A-I
activates lecithin acyltransferase
bound to HDL and chylomicros
Apolipoprotein B-48
found on chylomicros to facilitate secretion
Apolipoprotein C-II
cofactor for LPL
Klinefelter’s syndrome labs
Increased estradiol FSH increased Inhibin B decreased Testosterone decreased Elevated LH
Alpha-1,6-glucosidase deficiency
Cori’s disease (glycogen storage disease type III)
hepatomegaly and hypoglycemia
Porphyria cutanea tarda
deficiency of uroporphyrinogen decarboxylase
result of chronic Hep C
accumulations in uroporphyrin
present with cutaneous blisters and liver involvement
liver bx. = porphyrias as intracellular crystals (red under long wave UV light)
Calculate LDL
Total= HDL+LDL+(triglycerides/5)
Microarray
technique used to determine the relative differences in gene expression in one sample compared to another
Lead poisoning
elevated coproporphyrin
nonspecific anemia, constipation, encephalopathy, abd pain
basophilic stippling
lead lines
Hartnup
AR disorder presents like niacin deficiency
defective neutral amino acid transporter
supplement with niacin
Aldose reductase
turns glucose into sorbitol which causes osmotic damage
Citrate
Citrate is transported to the cytoplasm for fatty acid synthesis
Acute intermittent porphyria
deficiency of porphobilinogen deaminase
leading to accumulationgs of ALA and porphobiliniogen
diffuse abd pain and red urine
methanol toxicity
usually 12-24 hours after ingestion
similar to ethanol
metabolized by alcohol dehydrogenase (then into formic acid)
treat with ethanol or fomepizole
Famiial hypercholesterolemia
autosomal dominant mutation causing defective LDL receptors
xanthomas on tendons
Primary ciliary dyskinesia
both dynein and kinesin are involved in transport of substances within the cell
Pompe’s disease
Deficient in (acid maltase) lysosomal enzyme alpha-1,4-glucosidase
glycogen accumulates in lysosomes and cytoplasm
CARDIOMYOPATHY, hypotonia, hepatomegaly
cystinuria
heaxgonal crystals in urine with cystine kidney stones
treat with acetazolamide to alkalize urine
beriberi
thiamine deficiency
symmertric muscle wasting as well as neuro deficits
weakness (worse in LE)
Lafora body disease
rare AR disease in which many cells develop inclusion bodies known as Lafora bodies (stain with PAS which demonstrates glycogen, glycoproteins, or other carbs)
collagen synthesis
in the extracellular space the two steps are cleavage of C-terminal peptides and cross-linking of lysin and hydroxylysine
Promoter/
enhancer/
repressor
upstream/
anywhere/
anywhere
Marfan’s
AD mutation in fibrillin gene
aortic regurg diastolic decrescendo murmur along left sternal border
Base excision repair
involves cleaving damage bases from the sugar-phosphate backbone using enzymes called GLYCOSULASES
Acute intermittent porphyria
accumulation of porphobilinogen and delta-aminolevulinic acid int he urine
diffuse abd pain, redurine
deficiency in porphobilniogendeaminase
non-oxidative reactions of HMP shunt
involved in transformation of ribulose-5-phosphate into other sugars
these reactions are called transkeolase and transaldolase
lipoic acid is necessary for what enzymes
pyruvate dehydrogenase, a-ketoglutarate dehydrogenase, and BCAA dehydrogenase
deficiency causes lactic acidosis
nondisjunction during meiosis with identical alleles from one parent
anaphase II
Rotenone poisoning
inhibits complex I in mitochondria, leading to symptoms consistent with Parkinson disease
Stickler syndrome
mutations in COL2A1, COL9A1, COL11A1, and COL11A2 AD pattern most common abnormality of type II collagen vision and hearing loss abnormal facial features
Protein kinase C activation
Gq second messenger
PIP2 synthesis–> elevated DAG and IP3
DAG activates protein kinase C
IP3 leads to increased intracellular calcium
Heme synthesis
dependent upon sufficent quantities of glycine
Mannose 6-phosphate addition to proteins
occurs in golgi and send to lysosomes
Fates of pyruvate
Pyruvate carboxylase (oxaloacetate)
PDH (Acetyl-CoA + NADH)
LDH (Lactate +NAD+)
ALT (Alanine)
Paget’s disease
leads to high-output heart failure due to presence of mini AV fistulas in the bones
