Biochem Flashcards
Error in Meiosis I vs Meiosis II–what will RFLP fragments look like in a child with down’s syndrome?
Meiosis I: Will have three different chromosomes in the child
Meiosis II: will have duplicates of one chromosome and then one more chromosome
Symptoms of fragile X
Macroorchidism
Dysmorphic face
Cognitive impariment
Aggressiveness
What is the defect in fragile X? And which gene does it appear on?
Trinucleotide repeat CGG
–Occurs on FMR-1 gene on the X chromosome
Short broad finers and transverse palmar creases
Down’s syndrome
Precursor of tyrosine
phenylalanine
Precursor of catecholamines
tyrosine
precursor or urea and nitric oxide
arginine
Precursor of niacin
tryptophan
Pellagra features
dermatitis, diarrhea, dementia
Pellagra is a deficiency in
niacin
asymp pt with high fructosuria
defective fructokinase
How does pt with essential fructosuria metabolize fructose?
hexokinase converts it to fructose 6 phosphate when can then be converted to pyruvate through a number of steps
hexokinase
converts glucose–>G6P
converts fructose–>F6P (pathway not significant in normal individuals)
aldose reductase
converts glucose to sorbitol
PFK 1
Converts F6P to F1,6BP
FBP phosphatase-1
Converts F1,6BP to F6P
fructokinase
Fructose–>Fructose1P
Aldolase B
Fructose1P–>DHAP and glyceraldehyde
Triokinase
Glyceraldehyde–>G3P
G3P can then be used to generate pyruvate
Aldolase A (and B)
Combines G3P and DHAP to make F1,6BP
Carbon tetrachloride
Damages through free radical CCl3
–degrades lipis and produces hydrogen peroxide
how does huntington’s dz cause effects?
CAG repeats which causes hypermethylation of histones
Tx: lead poisoning
dimercaprol/EDTA
Rb gene regulates:
TUMOR suppressor that regulates G1-S transition
Rb tumor?
retinoblastoma
osteosarcoma
breast/lung/colon
Ras pathway
MAP kinase
Ras tumor
follicular thyroid cancer
Bcl2
follicular lymphoma
Gm2 ganglioside accumulation
Tay Sachs
heparan sulfate and dermatan sulfate accumulation
Deficiency in alpha-L iduronidase
Deficiency in alpha L iduronidase
Hurler syndrome
Glucocerebroside accumulation
Gaucher disease
Deficiency of glucose 6 phosphatase
Von Gierke
Deficiency of lysosomal alpha 1,4 glucosidase
Pompe disease
Accumulation of ceramide trihexoside
alpha galactosidase A deficiency
Fabry disease
angiokeratomas, acroparesthesia, hypohidrosis and renal failure
Fabry disease
Deficiency of sphingomyelinase
Niemann pick
Presentation of Niemann pick
Hepatosplenomegaly
hypotonia
cherry red macular spot
Foamy histiocytes
foamy histiocytes
Inheritance of niemann pick
autosomal recessive. Die by age 3
microganthia, low set ears, rocker bottom feet. Over-riding fourth and fifth fingers
Edwards syndrome, trisomy 18. Usually fetal death
cleft lip and palate polydactyly microcephaly rocker bottom feet umbilical hernia
Patau syndrome
Trisomy 13. Fetal death
Which vitamin is used to make NAD/NADH?
niacin
Four signs of niacin deficiency
dermatitis
dementia
diarrhea
death
Which vitamin is essential for a transamination reaction?
B6 (pyradoxine)
Transaminases are necessary for synethesizing amino acids
Thiamine is used in which enzymes
transketolase, alpha-ketoglutarate dehydrogenase, and pyruvate dehydrogenase
Riboflavin is used for:
FMN and FAD dehydrogenase rxns
Biotin is used for:
Carboxylases
- pyruvate carboxylase
- acetyl CoA carboxylase
- Propionyl CoA carboxylase
- 3-methylcrotonyl-CoA-carboxylase
Pleiotropy
One gene has many effects
Methotrexate inhibits
DHFR reductase. Results in a build up of DHF.
Blocks BOTH folid acid–>DHF AND DHF–>THF
Folinic acid is also known as
leucovorin. A form of THF that can bypass DHFR in pts getting methotrexate
5 FU
Inhibits thymidylate synthase which converts N5,N10 methylene THF back to DHF
Pantothenic acid
Makes coenzyme A. Necessary for AcetylCoA in first step of TCA+oxaloacetate–>citrate
Also synthesis of vitamin AD, cholesterol, steroids, lots of stuff
Sx of pantothenic acid deficiency
burning feet and GI distress
DiGeorge=deletion on chromosome…
22
Battery factories at risk for poisoning of:
lead. Also mining, chemical processing, radiator repair, recycling
Sx of lead poisoning
GI distress
lead line on gum
peripheral neuropathy (wrist/ankle drop)
Single palmar crease
Down’s syndrome
Resistance to chemotherapeutic agents (broad range) comes from
MDR1 gene for P-glycoprotein, a ATP dependent efflux pump
What does southwestern blot measure?
DNA-bound protein
You need lipoic acid for…
Pyruvate dehydrogenase (lactic acidosis) alphaketoglutarate dehydrogenase branched-chain ketoacid DH (maple syrup urine disease)
PDH co-enzymes
thiamine
lipoic acid
CoA, FAD, NAD_+
–>if absent, will build up lactate
Reye’s syndrome
giving aspirin to children causes:
- Hepatic dysfunction. Microvesicular steatosis with high ALT, AST, ammonia, and bili
- Encephalopathy of Reye’s. Hyperammonemia causes cerebral edema and coma
Osler-Weber-Rendu syndrome
telangiectasis in skin and mucosal membranes. Epistaxis, GI bleeding, hematuria result
Inheritance of osler weber rendu
Autosomal dominant
Which drugs inhibit DHFR?
Trimethoprim, methotrexate, and pyrimethamine
Elongation factorsq
facilitate tRNA binding and translocation in protein synthesis
How do you clinch the dx of riboflavin deficiency?
glutathione reducase assy
urinary riboflavin excretion
action of riboflavin
Used to synthesize FMN and FAD, components of Complex I and II.
- -Also, an electron carrier in TCA cycle
- -Also a cofactor for succcinate dehydrogenase
Explain the process of base excision repair
- glycosylase cleaves out wrong base pair match
- endonuclease cleaves 5’ end
- lyase cleaves 3’ sugar phosphate backbone
- DNA polymerase and ligase fill gaps
Cystic fibrosis causes what protein level changes?
defective post translational folding and glycosylation. Thus CFTR is degraded before it reaches the surface
leucovorin
N5-formyl THF does NOT need reduction by DHFR. Bypasses methotrexate block.
How does leucovorin interact with 5-FU
potentiates effect. 5-FU works better in the presence of folate in order to complex with thymidylate synthetase.
Trisomy 13 is caused by:
defect during maternal meiosis I
Nondisjunction in meiosis I causes
An extra chromosome, with an extra allele
Nondisjunction in meiosis II causes
An extrachromosome, with an extra IDENTICAL chromosome
47,xxx
clinically silent. maybe less IQ
47 xyy
phenotype=normal
tall, severe acne, some motor/language delays
long term complication of Edwards syndrome
meckel’s and malrotation
long term complication of patau
they usually die!
- holoprosencephaly, NTD
- PDA< ASD< VSD
- PCKD
- pyloric stnosis, omphalocele
HOCM caused by
cardiac sarcomere protein defect in the beta-myosin gene
HOCM inheritance
autosomal dominant
Causes of genetic dilated cardiomyopathy
AD dystrophin/mitochondrial enzyme mutations
Gallstones caused by
high cholesterol
low bile acids and low phosphatidylcholine
During times o plenty, what is the rate limiting step of fatty acid synthesis?
Acyl-CoA carboxylase
Glucose 6 phosphatase
Produces free glucose form glucose 6 phosphate
which enzyme catalyzes the first step in the beta oxidation pathway?
acyl CoA dehydrogenase
melting temperature of DNA depends on
GC content (3 hydrogen bonds)
hydroxyurea inhibits
ribonucleotide reductase
–UDP to dUDP
Ornithine transcarbamoylase deficiency leads to an accumulation of
carbamoyl phosphate–>orotic acid
6 mercaptopurine
Blocks purine synthesis
PRPP–>IMG
5 FU
inhibits thymidylate synthase
–lack of dTMP
methotrexate
blocks DHFR
–Converts DHF to THF needed for thymidylate synthase
trimethoprim
inhibits bacterial DHFR
Orotic aciduria
Inability to convert orotic acid to UMP
–Defect in UMP synthase
inheritance of orotic aciduria
autosomal recessive
Increase in orotic acid in urine, megaloblastic anemia that does NOT improve with B12, failure to thrive, No hyperammonia
orotic aciduria
Treatment of orotic aciduria
oral uridine administration
Aldolase B
Converts Fructose 1 P to DHAP and glyceraldehyde
which codons are NOT degenerate?
methionine and tryptophan
xanthine oxidase
Converts hypoxanthine–>xanthine
then
xanthine–>uric acid
adenosine deaminase converts
adenosine to inosine–>hypoxanthine
- -cannot break down adenine
- -excess adenine
- -feedback inhibition of ribonucleotide reductase
inheritance of adenosine deaminase
autosomal recessive
Lesch Nyhan syndrome
Loss of HGPRT
- -block of guanine to GMP
- -block of hypoxanthine to IMP
Retardation, self mutilation
aggression, hyperuricemia, gout, and choreoathetosis in a kid
Lesch-Nyhan
which amino acids are NOT degenerate?
methionine (AUG)
tryptophan (UGG)
commaless, nonoverlapping genetic code
read from a fixed starting point. a continuous sequence of bases
missense mutation
Changed amino acid
single origin of replication
prokaryotes
multiple origins of replication
eukaryotes
fxn: DNA topoisomerases
Nick in helix=relieve supercoils
DNA poly III
ONLY prokaryotic
–3’ to 5’ exonuclease activity for proofreading
DNA poly I
prokaryotic only. degrades RNA primer and replaces it with DNA.
5’–>3’ exonuclease activity
telomerase
Adds DNA to 3’ end of DNA to avoid loss of genetic material
nucleotide excision repair
ENDONUCLEASES cut out oligonucleotides with damaged bases
xeroderma pigmentosum
mutated nucleotide excision repair
base excision repair
GLYCOSYLASES remove damaged bases
base excision repair is important in
toxic or spontaneous deamination
ataxia telangiectasia mutation
nonhomologous end joining
what forms connection btw DNA bases?
3’ end OH attackes the phosphate on 5’
most abundant RNA
rRNA
longest RNA
mRNA
smallest RNA
tRNA
AUG in prokaryotes codes for
formylmethionine
Promoter
Site where RNA poly and other transcription factors bind to DNA upstream from gene locus
Enhancer
changes gene expression by binding transcription factors
Silencer
repressors bind here
Where are enhancers and silencers located?
Close to, far from, or within the gene
RNA poly I
rRNA. most numerous type of RNA
RNA poly II
mRNA, largest RNA
RNA poly III
tRNA
what’s different about the prokaryotic RNA?
it makes a single RNA polymerase
pt eats a mushroom called amanita phalloides and dies. Very high LFTs. mechanism?
a-amanitin
- -inhibits RNA polymerase II
- -Causes severe hepatotoxicity if ingested
heterogeneous nuclear RNA
initial RNA transcript. may NOT necessarily be translated
pre-mRNA vs heterogeneous
pre-mRNA is DESTINED for translation
where does mRNA processing occur?
In the nucleus.
–If no processing, then mRNA will NOT leave the nucleus
three processing steps in mRNA
- 5’ 7-methylguanosine cap
- polyadenylation tail
- splicing
polyadenylation signal
AAUAAA
pre mRNA vs RNA
RNA has been processed and left the nucleus
antibodies to snRNPs
lupus
snRNP function
Forms a lariat to remove introns
what is at the 3’ end of tRNA
CCA
Aminoacyl-tRNA synthetase
scrutinizes amino acid before and after binding tRNA to it
tRNA uses what energy source to attach AA?
ATP
tRNA uses what energy source to translocate tRNA from one ribosomal site to another?
GTP
antibiotic: binds 30 S and inhitibts formation of initiation complex, and causes misreading
aminoglycosides
Block aminoacyl tRNA from entering acceptor site
tetracyclines
Block peptidyl transferase
chloramphenicol
Blocks release of tRNA after it has donated AA
macrolides
trimming
removal of N/C propeptides from zymogens to generate mature proteins
p53 and hypophosphorylated Rb inhibit
G1 to S progression
RER vs cytosolic ribosomes
cytosolic ribosomes make proteins for intracellular use, not secretion.
Golgi actions
- modifies N oligosaccharide on asparagine
- adds mannose-6 phosphate to proteins for trafficking to lysosomes
- Adds O oligosaccharides on serine/threonine
coarse facial features
clouded cornea
restricted joint movement
high plasma levels of LYSOSOMAL enzymes
I cell disease.
Cause of I cell disease
failure of addition of mannose 6 phosphate to lysosome proteins
COPI protein
Transports within Golgi in RETROgrade fashion to ER
COPII protein
Transports within Golgi in ANTEROgrade fashion from ER to golgi
ubiquitin associated with
proteasome
peroxisome breaks down
long fatty acids and amino acids
bacterial infections
partial albinism
peripheral neuropathy
chediak higashi syndrome
dynein
retrograde transport (+ to -)
kinesin
anterograde transport (- to +)
Drugs that act of microtubules
mebendazole
griseofulvin
cholchisine
paclitaxel
WHat allows cilia to move?
axonemal dynein: an ATPase with a dynein arm
Intermediate filaments are used for
maintaining structure
- vimentin
- desmin
- cytokeratin
- lamins
- GFAP
vimentin stains for
connective tissue
desmin stains for
muscle
cytokeratin stains for
epithelial cells
GFAP stains for
neuroglia
Neurofilaments stains for
neurons
ouabain
inhibits the K bindings site of Na/K ATPase
Type I collagen
bone, skin, tendon
Type II collagen
cartilage
Type III collagen
Reticulin
Type IV collagen
Basement membrane
Ehler danhlos has what collagen defect?
type III
fibrillin fxn
sheath around elastin
fibronectin fxn
Binds integrins on cell surface to ECM components (ex: collagen)
Four steps of collagen synthesis INSIDE fibroblasts
- Synthesis (Gly-Pro-Lys)
- Hydroxylation of proline and lysine
- Glycosylation of hydroxylysine and triple helix formation held by H and disulfide bonds
- Exocytosis of procollagen into extracellular space
Four steps of collagen synthesis OUTSIDE fibroblasts
- cleavage of disulfide terminal regions of procollagen=ins=insoluble
- cross linking of lysine-hydroxyllysine to make collagen
vitamin C affects
hydroxylation of proline and lysine residues
ehlers danlos affects what part of collagen synthesis?
cross linking of tropocollagen
osteogenesis imperfecta inheritance
autosomal dominant
ehler danlos associated with
joint dislocation
berry aneurysms
organ rupture
Inheritance of alport syndrome
X linked recessive
presentation of alport
progressive deafness and nephritis
elastin fxn
stretchy component of skin, lungs, large arteries, ligamenta flava
Elastin is rich in what components?
Proline and glycine
what gives elastin its elastic properties
cross linking
Southwestern blot
identifies DNA binding proteins
- -with labeled oligonucleotides
- -Example: Leucine zipper
microarrays are used to detect
Single nucleotide polymorphism
Indirect vs direct elisa
Indirect: uses an antigen to detect an antibody
Direct: uses a test antibody to detect an antigen
RNA interference
dsRNA used to promote degradation of a target mRNA
Lac I
repressor protein
Lac P
promoter site
Lac O
operator region
Lac Z
B-galactosidase
Lac Y
permease (lets lactose into cell)
Describe Lac operon when lactose is not present
LAC I is being synthesized
- -repressor protein binds to operator preventing transcription
- -high glucose, low CAMP, no CAP binding
Describe lac operon when lactose IS present
Lactose binds repressor protein made by Lac I
- -operator is open
- -polymerase attaches
variable expressivity
phenotype varies among individuals with the same phenotype
pleiotropy
one gene multiple phenotypes (PKU)
linkage disequilibrium
tendency for alleles at 2 loci to occur together more frequently than expected by chance
Locus heterogeneity
mutations at different loci produce the same phenotype. Ex: albinism
heteroplasmy
Presence of both normal and mutated mitochondrial DNA
uniparental disomy
two copies of a chromosome from one parent, none from the other
heterodisomy
offspring is heterozygous for alleles, both from one parent
isodisomy
offspring is homozygous for alleles, both from one parent
heterodisomy= error in meiosis I or II?
Meiosis I
isodisomy=error in meiosis I or II?
Meisosis II
mental retardation hyperphagia obesity hypogonadism hypotonia
prader willi
mental retardation
seizures, ataxia
inappropriate laughter
angelman’s
Praeder willi caused by
Paternal allele not expression (mom is always silenced)
Angelman caused by
Maternal allele not expressed (dad is always silenced)
Praeder willi and angelman’s syndromes are on chromosome
15
stroke like episodes, lactic acidosis with ragged red fibers on modified Gomori trichrome stain
mitochondrial encephalopathy
myoclonic epilepsi with ragged red fibers
MERRF
achondroplasia inheritance
Dom
FAP inheritance
dom
cystic fibrosis inheritance
recessive
albinism inheritance
recessive
marfan’s inheritance
dominant
MEN inheritance
dominant
thalassemia inheritance
recessive
huntington’s inheritance
dominant
hereditary hemorrhagic telangiectasia (osler-weber, rendu) inheritance
dominant
spherocytosis inheritance
dominant
familial hypercholesterolemia inheritance
dominant
glycogen storage disease inheritance
recessive
hemochromatosis inheritance
recessive
phenylketonuria inheritance
recessive
sphingomyelinase inheritance
recessive
ADPKD chromosome
16
FAP chromosome
5
ADPKD associated with
berry aneurysms
mitral valve prolapse
telangiectasias,
nose bleeds
skin discolorations
AVMs
osler-weber rendu
Huntington’s disease located on chromosome
4
NF1 on chromosome
17
NF2 on chromosome
22
VHL on chromosome
3
CF gene on chromosome
7
fxn of CFTR channel
- secretes Cl- from lungs and GI tract
- reabsorbs Cl- from sweat
IN CF, this channel has a problem in post-translational processing, resulting in proteasomal degradation after synthesis
Tx: CF
N-acetylcysteine to loosen mucus plugs
X linked recessive disorders
B Wise Fool’s GOLD Has Silly HOpe
- -Bruton’s x linked agammaglobulinemia
- -Wiskott-Aldrich
- -Fabry’s
- -G6PD
- -Ocular albinism
- -Lesch-Nyhan
- -Duchenne’s
- -Hunter’s syndrome
- -Ornithine transcarbamoylase deficiency
huntington’s disease on chromosome
4
Duchenne’s caused by
deleted dystrophin. Longest gene, so higher rate of spontaneous mutation
Onset of becker’s
teens or YA
–Duchenne presents before 5 years of age
Function of Duchenne’s
Anchors muscle fibers in skeletal and cardiac
achondroplasia gene
FGF3
Large testes, jaw, and ears
autism
mitral valve prolapse
Fragile X
Fragile X gene
FMR1
trinucleotide in fragile X
CGG
myotonic distrophy mutation
CTG
friederich’s ataxia mutation
GAA
dx of CF
- excess chloride in sweat
2. transepithelial potential difference
pyruvate kinase
PEP–>pyruvate
lactate dehydrogenase
pyruvate–>lactic acid
pyruvate decarboxylase
pyruvate–>oxaloacetate
Pyruvate dehydrogenase
pyruvate–>acetylcoA
ultrasound shows increased nuchal translucency in first trimester
down’s syndrome or patau
quad screen in down’s syndrome
- decreased a-FP
- Increased bHcG
- decreased estriol
- increased inhibin A
Down’s syndrome=increased risk of
ALL
Alzheimer’s
Quad screen
- low aFP
- low hCG
- low estriol
- normal inhibin A
Edwards
Quad screen
- low hCG
- low pAPP-A
- Increased nuchal translucency
patau
most common cause of Down’s
meiotic nondisjunction
mental retardation, rocker bottom feet, congenital heart disease
–low set ears, micrognathia
Edwards. Die within 1 year
mental retardation, rocker bottom feet, congenital heart disease
- -cleft lip
- -polydactyly
- -holoprosencephaly
Patau. Die within 1 year
Robertsonian translocation
when short arms of chromosome are lost. balanced translocations usually are normal.
robertsonian translocation occurs on chromosome pairs
13,14,15,21,22
baby with high pitched mewing
- -microcephaly
- -retardation
- -epicanthal folds
- -VSD
Cri du chat
deletion in cri du chat
chromosome 5p
elfin facies
- -hypercalcemia
- -extreme friendliness with strangers
- -cardiovacscular problems
williams
Williams caused by deltion on
chromosome 7. includes deletion of elastin gene
22q11 deletion sx
CATCH 22
- Cleft palate
- abnormal facies
- thymic aplasia
- cardiac defects
- hypocalcemia
digeorge
22q11
-thymic, parathyroid, cardiac problems
velocardiofacial syndrome
22q11
-palate, facial, cardiac defect
vitamin toxicity most common with which vitamins?
A,D,E,K
B1
thiamine
B2
riboflavin
B3
niacin
B5
pantothenic acid
B6
pyridoxine
B7
biotin
B9
folate
vitamin C
ascorbic acid
which water soluble vitamins are stored for a long time in the body?
B12 and folate (in liver)
night blindness and dry skin
Vitamin A deficiency
arthralgias, fatigue, alopecia, sore throat, headaches
vitamin A excess
Thiamine is a cofactor for
- pyruvate dehydrogenase
- alpha ketoglutarate dehydrogenase
- transketolase
- branched chain amino acid dehydrogenase
alcoholic with malnutrition presents with polyneuritis, and symmetrical muscle wasting
Dry beriberi
alcoholic with malnutrition presents with dilated cardiomyopathy and edema
wet beri beri
riboflavin function
Cofactor in oxidation and reduction (FADH2)
cheilosis, corneal vascularization
vitamin B2 deficiency
niacin fxn
NAD and NADP+ component
niacin is derived from
tryptophan
synthesis of niacin requires
B6
pellagra
niacin deficiency
diarrhea, dementia, dermatitis
pellagra
hartnup disease
decrease in tryptophan absorption
causes of niacin deficiency
- malignant carcinoid (use up all your tryptophan)
- INH (low B6)
- pellagra
fxn: pantothenate
component of CoA and fatty acid synthase
dermatitis, enteritis, alopecia
–adrenal insufficiency
B5 deficiency
pyridoxine fxn:
- heme synthesis
- neurotransmitter synthesis
- transamination, decarboxylation, and glycogen phosphorylase
convulsions, hyperirritability, peripheral neuropathy, sideroblastic anemias
pyridoxine deficiency
Biotin fxn
- pyruvate carboxylase
- acetyl coA carboxylase (acetylCoA–>malonylCoA)
- propionyl-CoA carboxylase (propionyl-CoA–>methylmalonylCoA)
excessive ingestion of raw eggs with dermatitis, alopecia, enteritis
biotin deficiency
Folic acid use
Makes THF, tetrahydrofolate
B12 vs folate deficiency
B12 has neuro symptoms
which vitamins do you get from leafy green veggies?
- Vitamin A
2. Vitamin B9 (folate)
vegans at risk for which vitamin deficiency?
B12
subacute combined degeneration
B12 deficiency
infectious cause of B12 deficiency
diphyllobothrium latum
B12 is a cofactor for
- homocystein methyltransferase
2. methylmalonyl-CoA
S-adenosyl-methionine
donates methyl units
–converts NE to epinephrine
regeneration of methionine is dependent on
B12 and folate
methionine is made of
homocystein + CH3
To regenerate homocystein, you need
homocystein methyltransferase
–>Addsmethyl group from THF-CH3
vitamin C helps with the absorption of
iron. Therefore, don’t give to people with hemochromatosis or regular transfusions
vitamin C fxn
hydroxylation of proline and lysine in collagen synthesis
–dopamine B hydroxylase: converts dopamine to NE
hypercalcemia and hypercalciuria in pt taking too many vitamins
Vitamin D overdose.
vitamin D overdose is more common in what condition?
sarcoidosis
Vitamin E fxn
protects erythrocytes and membranes from free radical damage
hemolytic anemia and posterior column demyelination: what vitamin deficiency?
vitamin E. E is for erythrocytes
Vitamin K fxn
gamma carboxylation of gutamic acid on clotting proteins
which vitamins are missing from breast milk?
Vitamin D and K
loss of smell, delayed wound healing, hypogonadism, and decreased adult hair
ziinc deficiency–predisposes to alcoholic cirrhosis
fomepizole use
For methanol or ethylene glycol poisoning
mech: fomepizole
inhibits alcohol dehydrogenase
disulfiram mechanism
inhibits acetaldehyde dehydrogenase
Explain how ethanol causes acidosis and fatty acid synthesis and hypoglycemia
All caused by increased push to regenerate NAD+
- pyruvate–>lactic acid
- oxaloacetate–>malate
- ->malate excess inhibits gluconeogenesis
- ->shuts down TCA cycle
- ->acetylcoA goes to ketone
- ->excess NADPH from breakdown of malate
- ->fatty acid synthesis
Kid with malnutrition, edema, anemia, and fatty liver
Kwashiorkor
marasmus
muscle wasting from malnutrition
Fatty acid synthesis occurs in the
cytoplasm
HMP shunt occurs in the
cytoplasm
acetylcoA production occurs in the
mitochondria
Which processes occur both in the mitochondria and cytoplasm?
heme
gluconeogenesis
RDS glycolysis
PFK1
RDS gluconeogenesis
F1,6 bisphosphonate
RDS TCA cycle
isocitrate dehydrogenase
RDS glycogen synthesis
glycogen synthase
RDS glycogenolysis
glycogen phosphorylase
RDS HMP shunt
g6PD
RDS pyrimidine synthesis, de novo
carbamoylphosphate synthetase II
RDS purine synthesis de novo
glutamine PRPP amidotransferase
RDS urea cycle
carbamoyl phosphate synthetase I
RDS fatty acid synthesis
AcetylCoA carboxylase
RDS fatty acid oxidation
carnitine acyltransferaseI
RDS ketogenesis
HMG coA synthase
What regulates carnitine acyltransferase I in fatty acid oxidation?
malonyl coA inhibits
Glucokinase found in
Liver and beta cells of the pancreas.
which is induced by insulin, glucokinase or hexokinase?
glucokinase. High capacity but low affinity
Very long chain fatty acids are degraded by
peroxisomes. Cannot undergo beta oxidation by mitochondria
8 month old with hyperactivity, tremor, and seizures. Pt has blue eyes, fair skin, and mousy odor
Phenylketonuria
What do you need to supplement PKU with?
Tyrosine. Can no longer synthesis tyrosine from phenylalanine
Describe the G protein pathway
- Activation of adenylate cyclase
- Activation of protein kinase A
- physiologic effects
Which hormones use G protein receptors?
- TSH
- Glucagon
- PTH
- Beta adrenergic receptors
Pt presents with increased serum methionine and severe chest pain and MI
homocystinuria.
–defect in cystathionine beta synthetase (converts homocystine to cystathionine.
Most common cause of PKU
deficiency of phenylalanine hydroxylase
mutation in Sickle Cell Disease
Pt replaces glutamate with valine, a nonpolar amino acid. This changes the charge
–In hemoglobin C, lysine replaces the glutamate residue, making it less negatively charged. Usually asymptomatic but mild hemolytic anemia and splenomegaly
Effect of hyperammonia in the brain
depletion of glutamate and accuulation of glutamine
ALA synthase requires what vitamin?
pyridoxal phosphaet
tyrosine kinase effect after binding
phosphorylation of protein phosphatase
Why is Fructose 1 phosphate metabolized much faster than glucose?
It bypasses the major regulatory step in glycolysis=PFK1
HGPRT converts
guanine back to GMP
and
Hypoxanthine to IMP
adenosine deaminase
coverts adenosine to inosine to be broken down to hypoxanthine or recycled to IMP
16S rRNA in prokaryotic ribosome
Contains complementary mRNA sequence necessary for binding shine delgarno and translation
Translocation of aatRNA requires
GTP
23S rRNA
facilitates peptide bond formation
which vitamin can you give to a kid with measles?
vitamin A
how is alanine converted back to pyruvate?
combined with a-ketoglutarate
Describe the mTOR pathway
- autophosphorylation of tyrosine
- Phosphoinositide 3 kinase activation
- Activation of protein kinase B
- Increased gene transcription
- -THIS PATHWAY IMPORTANT IN APOPTOSIS AND CEL PROLIFERATION