Biochem Flashcards
1
Q
what is methotrexate’s MOA
A
folic acid analog that competitively inhibits DHF reductase
this decreases DNA synthesis
2
Q
what can methotrexate be used in
A
rapidly dividing cells:
cancers ectopic pregnancy medical abortion (+ misoprostol) Rheumatoid Arthritis (1st line) Psoriasis
3
Q
what are the 2 reasons for homocystinuria
A
Homocysteine can’t go one of two ways:
can’t go to Methionine
via Methionine synthase and B12
can’t go to Cystathione/Cysteine
via Cystathione-B-Synthase (CBS) and B6
4
Q
how do you treat methionine-synthase deficient homocystinuria
A
high methionine in diet
methionine is now essential
5
Q
how do you treat CBS-deficient homocystinuria
A
many respond dramatically to Vitamin B6 to “force” CBS activity
also reduce intake of methionine, which is the other direction of the homocysteine pathway
6
Q
how does a homocystinuria pt present
A
marfanoid habitus kyphosis ectopia lentis osteoporosis developmental delay thrombosis, atherosclerosis (early COD)
very high homocysteine
7
Q
Go through Fabry disease
A
“fabric”
bathing trunk, mittens and socks
-angiokeratomas in bathing trunk distribution
-acroparthesias (burning hands/soles)
you have a “galaxy” of skin spots
-alpha-galactosidase A
when you get older, you have to cover up your kidneys and heart with more fabric
-late stage = progressive renal failure, CVD
“Men fabricate lies about their hunting skills”
-Fabry and Hunter = X-linked
8
Q
go through Gaucher disease
A
HSM (similar to Neimann-Pick) (1 and 2 on the page)
“crumpled grocery bag with your macros: pans, Erlenmeyer flasks, liver, glucose, and iPhone 3G”
- lipid laden macrophages resembling crumpled tissue paper
- macrophages
- pancytopenia
- Erlenmeyer flask femur bone deformities
- liver = HSM
- glucose and 3G = glucocerebrosidase, glucocerebroside
9
Q
go through Neimann-Pick disease
A
HSM (similar to Gaucher) (1 and 2 on the page)
cherry-red spot (2 and 3 on the page; has a hyphen)
“No man would pick his nose with his springer because the boogers would make him fat”
- sphingomyelinase, sphingomyelin
- fat = HSM
10
Q
go through Tay-Sach disease
A
cherry-red spot (2 and 3 on the page; has a hyphen)
“Tay-Sach lacks hexosaminidase”
Taylor’s gang has a weird build-up of onion-skin-heads with GM2’s on the side”
- onion-skin lysosomes
- GM2 ganglioside
11
Q
go through Krabbe disease
A
“Grab a galaxy of milky boobs, bro”
- galaxy/milky and bro = galacto-cerebrosidease, galacto-crebroside
- boobs = globoid cells
12
Q
go through Metachromatic Leukodystrophy
A
“Look at this trophy”
-leukodystrophy
“April Fools Day”
-Arylsulfatase
“See bro, so fake”
-cerebroside sulfate
13
Q
go through Hurler syndrome
A
“Hurley (from Lost) tried to be tough like the Hunters, but wasn’t smart, couldn’t see, too fat, and too ugly”
- developmental delay
- corneal clouding
- HSM
- gargoylism/course facial features
both Hurler and Hunter accumulate Heparan sulfate
14
Q
go through Hunter syndrome
A
"'Hunters see clearly and aggressively aim for the X" "Men hunt" -no corneal clouding -Hurler + aggressive behavior -X-linked
both Hurler and Hunter accumulate Heparan sulfate
“Men fabricate lies about their Hunting skills”
-Fabry and Hunter are X-linked
15
Q
what is methylmalonic acidemia
A
metabolic acidosis 2/2 defective methylmalonyl-CoA mutase.
This enzyme normally converts Methylmalonyl-CoA to Succcinyl CoA, to enter the TCA cycle.
A defect in this enzyme will present in the neonatal period with:
- high methylmalonyl CoA (build up)!!
- high Propionyl CoA (previous step build up)!!
- hyperammonemia
- ketotic hypoglycemia
- metabolic acidosis
- lethargy, hypotonia, vomiting, respiratory distress
16
Q
what are the functions of the HMP shunt
A
pentose phosphate pathway:
provides NADPH, used in:
- glutathione reduction in RBCs
- Fatty acid and cholesterol biosynthesis
- nucleotide synthesis
17
Q
what is the rate-limiting enzyme for the HMP shunt
A
G6PD
glucose-6-phosphate dehydrogenase
18
Q
what does transketolase do
A
allows reversible transition between:
Fructose-6-Phosphate and Ribose-5-Phosphate
The fructose-6-Phosphate is a glycolysis intermediate, which could go on to enter the TCA cycle to give ATP
the Ribose-5-Phosphate could go on to make nucleic acids
19
Q
what are pyruvate’s options
A
it’s coming from PEP in the glycolytic pathway, so it’s planning to go to Acetyl-CoA via Pyruvate Dehydrogenase
and then enter the TCA cycle and provide energy.
but if Acetyl CoA is high, that shunts Pyruvate to skip over to make Oxaloacetate via Pyruvate Carboxylase
from here, the oxaloacetate can go back up to PEP via PEP carboxykinase and re-enter gluconeogenesis to provide blood glucose.
This would happen when a pt’s blood sugar levels are low. Acetyl-CoA’s high level helps the body make this decision to make more glucose in the blood.
20
Q
what does a G6PD deficiency present with
A
hemolytic anemia during times of oxidative stress
because you’re not producing the NADPH to keep reducing glutathione in RBCs to prevent RBC damage.
The oxidative stress precipitates the Hb out as Heinz bodies, which are then removed by the spleen, creating bite cells
21
Q
what enzyme deficiency can present similarly to G6PD deficiency
A
glutathione reductase
glutathione recutase helps use the NADPH to reduce the oxidized-glutathione back to regular/reduced/ready-to-use glutathione
it has similar consequences of cells precipitating out their Hb in oxidative stress situations because it’s unable to utilize the NADPH to keep reducing glutathione
22
Q
how does orotic aciduria present
A
Early failure to thrive, developmental delay (physical and mental)
high orotic acid levels
megaloblastic anemia!!!
(NO hyperammonemia!!!)
(!!! = vs OTC deficiency)
defect in UMP synthase to catalyze orotic acid–> UMP, so you have high orotic acid buildup
treat with URIDINE supplementation
“when UR DINING “orrotic-ly” UR a mega-blast”
23
Q
how does OTC deficiency present
A
high orotic acid levels
Hyperammonemia!!!
(NO megaloblastic anemia!!!)
(!!! = vs orotic aciduria)
defect in OTC, which is supposed to combine carbamoyl phosphate + Ornithine –> citrulline in the Urea cycle
excess Carbamoyl phosphate –> orotic acid
via pyrimidine synthesis pathway
“HYPER-AMMY takes too many OTC drugs in her PYRAMID CAR, so she’s not-a-blast”
24
Q
what do spliceosomes remove
A
introns containing GU at the 5’ splice site and AG at the 3’ splice site
splice site mutations may result in removal of exons and retention of introns
25
when are ketone bodies produced
ketone bodies are produced in the liver when the liver's glycogen stores have been depleted, and glujconeogeneis has been going on for a while to compensate during prolonged fasting. The body starts shifting away from gluconeogenesis and towards ketone body synthesis
26
what can/can't ketones be used for
Ketones can be used as an energy source in the mitochondria of peripheral tissue during fasting.
They require mitochondria, so cannot be used in RBCs.
27
what are the counter-regulatory hormones that protect the body from hypoglycemia during fasting
Glucagon
Epinephrine
Cortisol
Growth Hormone
(low insulin)
28
what effect does decreased insulin have during fasting state
decreases peripheral glucose utilization, so your blood glucose level isn't further depleted
it also sends a signal to increase hepatic gluconeogenesis and glycogenolysis to make more glucose to put sugar into the blood
29
what 3 molecules help to increase hepatic gluconeogenesis and glycogenolysis during fasting
Glucagon
Epinephrine
LOW insulin
they keep blood glucose levels high by increasing hepatic gluconeogensis and glyogenolysis to make more glucose to put sugar into the blood
"glucagon, for when glucose is gone"- it's the first responder
30
what effect does cortisol and GH have during fasting state
they alter transcription of many genes to converse glucose during a fasting state to minimize further blood glucose loss during PROLONGED fasting.
Cortisol receptors are within the cytoplasm.
GH receptors are membrane-bound.
(glucagon and EPI as its back-up are the immediate responders to low blood glucose)
31
what is the major rate-limiting step in glycolysis
Phosphofructokinase-1
(PFK-1)
it catalyzes Fructose-6-Phosphate to Fructose-1,6-Bisphosphonate
anything inserted into glycolysis after this step will be quickly metabolized. this would be dietary fructose
(mannose, galactose, glucose, all enter higher up and are metabolized slower)
32
what does Arginase do
makes Urea and Ornithine from Arginine in urea cycle
```
Arginase deficiency is going to present with:
High arginine (build up)
spastic diplegia
abnormal movements
growth and developmental delay
```
MILD OR NO HYPERAMMONEMIA (vs other urea cycle disorders)
just remember Arginine is a key player in the urea cycle
33
what is lactose broken into
Lactose -->
Galactose + glucose
via Lactase
34
what is classic galactosemia
deficient GALT
galactose-1-phosphate uridyl transferase
(T = "traditional"/classic)
this is the severe form of galactosemia (vs mild GALK)
in the last step of galactose breakdown, Galactose-1-Phosphate cannot be converted to Glucose-1-Phosphate to enter the glycolysis/gluconeogenesis pathways
build up of galactose, so you get SEVERE symptoms in a newborn:
jaundice, vomiting, HSM, renal dysfunction, E coli sepsis, cataracts, hemolytic anemia
galactose can come from Lactose in breastmilk, so this presents early in life with SEVERE galactosemia
you need to switch to soy milk and exclude lactose and galactose from diet
35
what is galactokinase deficiency
deficient GALK
relatively mild condition where galactitol accumulates
because you can't do the first step in converting galactose --> Galactose-1-Phosphate to make it back to the glucose pathway
symptoms will develop when an infant begins feeding because breast milk has lactose which goes to galactose + glucose
baby will get high galactose levels and infantile cataracts (can't track objects or see your social smile)
galactoKINase deficiency is KIND enough to not be severe (vs severe GALT)
36
Run through Von Gierke disease
Type 1 Glycogen storage disease (VPCM)
defect in Glucose-6-Phosphatase
Glucose-6-Phoshate --> Glucose
it's the last step in breaking glycogen into glucose in the liver
Presents with:
SEVERE fasting hypoglycemia (because liver can't do gluconeogenesis)
very high glycogen in liver (glycogen is trapped)
high triglycerides, high uric acid (gout)
HEPATOMEGALY (things are stuck in the liver)
treat:
frequent oral glucose/cornstarch to avoid fasting hypoglycemia
avoid fructose and galactose (that have to be broken down to glucose to be used)
it's the last step in glycogenolysis and glujconeogeneis, so both are impaired
37
Run through Pompe disease
Type 2 Glycogen Storage disease (VPCM)
defect in alpha-1,4-glucosidase ONLY IN LYSOSOMES
AKA Acid Maltase deficiency
cannot take Glycogen --> glucose in the lysosomes
"Pompe trashes the pump"- presents with CARDIOMEGALY
early death <2yo
pts will have normal blood glucose levels (problem is only in lysosomes)
lysosomes will be PAS (+) for glycogen
(hearts have 4 chambers, so remember alpha-1,4-glucosidase)
38
Run through Cori Disease
Type 3 Glycogen Storage Disease (VPCM)
defect in alpha-1,6-glucosidase "Debranching Enzyme"
```
mild form of Von Gierke
normal blood lactate levels
accumulation of Dextrin-like molecules (nubs)
ketoacidosis
hypotonia
```
"Your core has a 6-pack, so this is a 1,6 deficiency"
"a,b, C-->D for Cori --> Debranching and Dextrin-like accumulation"
"Cori Can't Cleave"
Gluconeogenesis is intact (because you don't always have to be
39
Run through Anderson's disease
glycogen storage disease that isn't one of the fab 4
defect in Branching enzyme
"A --> B, c,d" (like Cori--> Debranching)
"Anderson can't Add"
40
Run through McArdle Disease and Hers disease
McArdle:
Type 5 glycogen storage disease (VPCM)
defect in Muscle glycogen phosphorylase (Myophosphorylase)
can't complete the first step in muscle glycogen breakdown
```
present with:
high muscle glycogen (stuck)
painful muscle cramps
myoglobinuria with exercise
second-wind phenomenon due to increased muscle blood flow
```
```
Hers:
Type 6 glycogen storage disease
defect in HEPATIC glycogen phosphorylase
Hepatomegaly (glycogen is trapped)
poor growth
symptoms improve with age
```
both have normal glycogen and normal glucose structure because the defect is in the very first step of glycogen breakdown
41
Run through essential fructosuria
defect in Fructokinase
Fructose --> Fructose-1-Phosphate
via fructokinase
benign, asymptomatic,
since Fructose is not trapped in cells-
it can go back to glucose via Hexokinase
positive Copper reduction test
"Hexokinase is "essentially" "kind" enough to make fructokinase asymptomatic"
42
Run through fructose intolerance
defect in Aldolase B
Fructose-1-Phosphate --> one of two:
DHAP --> Glycolysis
Glyceraldehyde --> glycerol
presents with fructose intolerance because:
Fructose-1-Phosphate gets trapped
you get hypoglycemia, jaundice, cirrhosis, vomiting
Treat:
don't eat fructose or sucrose (glucose + fructose)
43
what is the energy source in aerobic conditions
pyruvate is converted to acetyl-CoA to enter the TCA cycle
44
what is the engird source in anaerobic conditions
when oxygen is depleted (exercising muscle),
| pyruvate is converted to lactate
45
what is a limited molecule needed for glycolysis
NAD+
it is limited, and must be regenerated from NADH for glycolysis to continue
46
how is NAD+ used in aerobic glycolysis
NAD+ is converted to NADH in the TCA cycle under aerobic conditions
NADH is then reconverted to NAD+ in the Electron transport chain, as the energy in NADH is utilized in making ATP for energy
47
how is NAD+ used in anaerobic glycolysis
in anaerobic glycolysis,
NAD+ is regenerated from NADH when pyruvate converts to lactate via lactate dehydrogenase
48
what happens to glycolysis in lactate dehydrogenase deficiency
in lactate dehydrogenase deficiency,
glycolysis is inhibited in strenuously exercising muscles, because muscles cannot regenerate NAD+ from NADH (need lactate dehydrogenase)
high physical activity leads to muscle breakdown, pain, and fatigue 2/2 insufficient energy being produced
49
what is phenylketonuria PKU
defect in phenylalanine hydroxylase or BH4 cofactor
tyrosine becomes essential
50
what is a rare cause of PKU
defect in dihydrobiopterin reductase, which converts BH2--> BH4
if you have a defect in this, then you have low BH4
normally:
Phenylalanine Tyrosine Dopamine
in this rare cause of PKU, you'll have low dopamine 2/2 low Tyrosine, so pts will present with Prolactinemia (lack of Dopamine inhibition)
51
what amino acid is involved in dopamine synthesis
Tyrosine
52
how do PKU pts present
```
intellectual disability by 6mo
seizures
fair skin/ hypo pigmentation
eczema
musty body odor (disorder of aromatic amino acid metabolism- "aroma" = musty)
```
treat with low Phenylalanine and essential Tyrosine
avoid aspartame
53
what does primase do
it is a DNA-dependent RNA polymerase that incorporates short RNA primers into replicating DNA
it may be the reason you find partially replicated DNA fragments with Uracil present
54
how does B12 vs B9 vs B6 present
```
B12:
takes years to develop (large hepatic reserve)
megaloblastic anemia
subacute combined neurodegeneration
strict vegan for many years
gastrectomy years ago
high homocysteine AND methylmalonic acid
```
```
B9:
High homocysteine
Neural tube defects (low folate)
megaloblastic anemia
hypersegmented Neutrophils
glossitis
NO neuro symtoms
alcoholism
pregnancy
most common Vit deficiency in US
```
```
B6:
peripheral neuropathy
convulsions
hyper-irribility
siderobalstic anemias (excess Fe and impaired Hb synthesis)
caused by Isoniazid and OCPs
```
55
what does hormone-sensitive lipase do
enzyme in adipose tissues that metabolizes triglycerides into:
glycerol + fatty acids
these 2 products can be used in times of starvation/fasting to maintain blood sugar levels
56
how is glycerol used during fasting
glycerol is made in adipose tissue by:
triglycerides + Hormone sensitive lipase -->
Glycerol + fatty acids
glycerol then travels to hepatocytes
glycerol --> Glycerol-3-Phosphate
via Glycerol kinase
Glycerol-3-Phosphate--> DHAP
DHAP --> Gluconeogenesis / Glucose
57
how are fatty acids utilized during fasting/starvation
Triglycerides use Hormone sensitive lipase in adipose tissue to break into:
Glycerol + Fatty acids
Fatty acids are then made into ketone bodies, which provide energy to tissue during fasting
Free Fatty Acids do not cross BBB, so only ketones can be used by the brain during fasting
Erythrocytes can also only use ketones because they an only use glucose due to lack of mitochondria
58
what does pyruvate kinase do
Phosphoenolpyruvate --> Pyruvate
59
what does pyruvate dehydrogenase do
Pyruvate --> Acetyl CoA to enter the TCA cycle
works in the PRESENCE OF OXYGEN
60
what does Pyruvate carboxylase do
Pyruvate --> oxaloactete near the end of the TCA cycle (to re-enter gluconeogenesis)
61
what does Lactate dehydrogenase do
Pyruvate --> Lactic acid
works in the ABSENCE OF OXYGEN
62
which path does pyruvate take based on the availability of oxygen
Pyruvate --> Acetyl-CoA
via pyruvate dehydrogenase
in the PRESENCE OF OXYGEN
(accumulation of NADH inhibits pyruvate dehydrogenase in hypoxic conditions)
pyruvate --> Lactic acid
via LDH
in the ABSENCE OF OXYGEN
63
what serves as the amino acid binding site on a tRNA
the 3' CCA tail
64
what enzyme is responsible for loading the appropriate amino acid to the 3' terminal -OH group of the CCA tail
aminoacyl tRNA
65
what does fibrillin-1 do
it's an extracellular glycoprotein that acts as a scaffold for elastin
it's abundant in the zonular fibers of the lens, periosteum, and aortic media
defects (Marfan syndrome) commonly cause aortic root dilation with dissection and rupture
66
what does Ehlers Danlos affect
the formation and extracellular structuring of collagen (rather than microfibrils in Marfans)
67
what is the function of snRNPs and who has trouble with their function?
snRNPs are essential parts of spliceosomes, which remove introns from pre-mRNA to form mature mRNA.
Pts with SLE have anti-Smith antibodies, which are antibodies against snRNPs
68
what does Thiamine deficiency cause
beriberi and Wernicke-Korsakoff syndrome
Dry BeriBeri:
symmetrical peripheral neuropathy
Wet BeriBeri:
neuropathy and high-output CHF
69
how is the Lac operon regulated:
2 distinct mechanisms:
Negatively,
by binding of the repressor protein to the operator locus
Positively,
by cAMP-CAP binding upstream from the promotor gene
if you have constitutive expression of a gene, then the mutation is in the impaired repressor function (operator locus)
70
what activates cGMP
NO
71
what activates protein kinase C
Gq and increase in intracellular Ca
72
how does Gq protein signaling work
ligand binds to Gq
Gq activates Phospholipase C
forms DAG and IP3
IP3--> Protein Kinase C
via increase in intracellular Ca
73
how can gout develop
activating mutations involving PRPP synthetase due to increased production and degradation of purines
74
how do heme disorders present, depending on where in the process is disordered
early mess up:
neuropsychiatric manifestation
late mess up:
photosensitivity
75
what is deficient in Porphyria cutanea tarda
urophyrinogen decarboxylase (UROD) deficiency
presents with photosensitivity and blisters
most common heme synthesis problem
76
what is the defect in lead poisoning
Ferrochetalase (and ALAD)
it's the last step in heme synthesis, which takes
protoporphyrin and iron--> heme
presents with photosensitivity
77
what is the defect in Acute intermittent porphyria
Prophobilinogen deaminase (PBG deaminase)
it's an earlier mistake in heme synthesis, so it presents with neuropsychiatric symptoms rather than photosynthesis
78
what is the defect in sideroblastic anemia
delta-ALAS
it's the first step in heme synthesis, and is also the rate-limiting step
79
what does IL-2 do
produced by helper T cells to stimulate CD4 and CD8 and NK cells, and B cells
IL-2 has an anti-cancer effect via activation of T and NK cells
80
what is the defect in Type 1 familial hyper-chylomicronemia
Lipoprotein lipase or ApoC-II
you see high blood chylomicrons and "creamy layer in supernatant" with a risk of acute pancreatitis
81
what is the defect in familial hypercholesterolemia
absent or defective LDL receptors (ApoB-100)
see high blood LDL
accelerated atherosclerosis, MIs, and tendon xanthomas
82
what does PCR require
requires primers that are complementary to the regions of DNA flanking the segment of interest
also thermostable DNA polymerase, deoxynucleotide triphosphate, and a source DNA template strand
83
what are the 3 steps of PCR
Denature:
denaturing the DNA template with high temp
Annealing:
primers combine w/ the single stranded flanking ends of the target region when temp is lowered
Elongation:
DNA polymerase forms new daughter DNA strands
these are repeated to obtain millions of copies of the target DNA segment in a short period of time
84
what amino acid do catecholamines come from
Tyrosine
85
what is the first step in catecholamine synthesis
conversion of tyrosine to DOPA by tyrosine hydroxylase, which is the rate limiting step of synthesis
86
what converts DOPA to dopamine
Dopa decarboxylase
87
what converts dopamine to NE
dopamine beta-hydroxylase
88
what converts NE to Epinephrine
PNMT, which is unregulated by Cortisol in stress. this happens in the adrenal medulla
PNMT = phenylethanolamine-N-methyltransferase
89
what is the deficient enzyme in hypoketotic hypoglycemia of Medium-Chain Acyl-CoA dehydrogenase deficiency MCAD deficiency?
acyl-CoA dehydrogenase
this is supposed to take fatty acyl-CoA and turn it into acetyl-CoA in the mitochondria
acetyl-CoA will then go on to either the TCA cycle or to make ketone bodies. ketone bodies won't be made in this disease though
90
what is the problem with hypoketotoic hypoglycemia, regardless of which type you have
during fasting, pts cannot oxidize fatty acids for energy or produce ketone bodies
their labs may say "NO ACETOACETATE"
91
what is systemic carnitine deficiency
another defect that will give you hypoketotic hypoglycemia
it's an inherited defect in the transport of fatty acids into the mitochondria
it causes:
muscle weakness, hypotonia, cardiomyopathy!!, and hypoketotic hypoglycemia
92
where does Vitamin C act as a cofactor in the cell
in the RER
to aid in hydroxylation of proline and lysine in collagen residues
93
what does alanine transfer its amino group (NH3) to so it can become glucose?
alpha-ketoglutarate
alpha-ketoglutarate then turns into glutamate and is excreted as urea
so alanine is the primary amino acid responsible for transferring N to the liver for disposal
94
what's an easy way to diagnose thiamine deficiency
low erythrocyte transketolase activity
| part of the "A-T-P" molecules that B1 is a cofactor in making. seen with alcoholics commonly
95
what happens with hyperammonemia in advanced liver failure
the cirrhotic liver is unable to metabolize nitrogenous waste products
Ammonia crosses the BBB and causes excess glutamine to accumulate within astrocytes
this decreases the the amount of glutamine available for conversation to glutamate in neurons, resulting in disruption of excitatory transmission
96
how does the body maintain blood glucose during fasting
it first uses glycogenolysis from hepatic stores for the first 12-18 hours.
once hepatic glycogen stores have been depleted, it switches to gluconeogenesis,
where pyruvate goes back to the gluconeogenesis cycle via oxaloacetate and PEP carboxylase.
all the other pathway options pyruvate can take may be used for energy, but this is the path the body takes for blood glucose
97
who do you treat AIP
give heme, which down regulates ALA-synthase activity, the rate-limiting step to heme synthesis
98
what is the defect in X-linked sideroblastic anemia
delta-ALA-synthase
it's the (first) rate-limiting step in Heme synthesis
99
what are the 2 possible enzyme defects in lead poisoning
delta-ALA-dehyratase
(psych symptoms)
ferrochelatase
(photosensitivity)
these are both steps in heme synthesis
100
where is hepcidin synthesized
hepatic parenchymal cells
101
what does hepcidin do
acts as a central regulator of iron homeostasis.
Hepcidin interacts with ferroportin (transmembrane protein)
When hepcidin binds to ferroportin, it's internalized, so intestinal iron absorption is decreased and Fe release from macrophages is inhibited
high iron and inflammation increase hepcidin
hypoxia and erythropoiesis lowers hepcidin
102
what 2 processes use BH4 as a cofactor
Phenylalanine --> tyrosine
Tryptophan --> Serotonin
103
what does tyrosine make
Thyroxine
Dopa --> Melanin
Dopa --> dopamine
Dopamine --> NE
NE --> EPI
104
what does serotonin make
melatonin
105
what step does G6PD specially catalyze
Glucose-6-Phosphate -->
| 6-Phosphogluconate
106
what is Ehlers-Danlos pathophysiology
pro collagen peptidase deficiency, which results in
impaired cleavage of terminal pro peptidases in the extracellular space, or
"N-terminal propertied removal"
defect in cross-linking with copper-containing lysyl oxidase
107
what determines protein folding structures
hydrogen bonding- this is SECONDARY STRUCTURE
alpha helix: every 4th amino acid
beta-pleated sheet: between all residues of antiparallel strands
108
what determines tertiary structure of proteins
ionic bonds
hydrogen bonds
disulfide bonds
hydrophobic interactions
109
what are the defects in lead poisoning
lead inhibits ferrochelatase and
d-ALA-D
causing anemia, ALA accumulation, and elevated zinc protoporphyrin levels
neurotoxicity is a long-term complications
110
which organelle degrades VLCFAs
peroxisomes
111
which dislipidemia has a defect in ApoE
Type 3- familial disbetaliporoteinemia
elevated cholesterol and triglyceride levels
decreased clearance of chylomicrons and VLDL remnants
palmar xanthomas and athersclerosis
112
what is elevated in familial hypercholesterolemia
LDL
defect in LDL receptors and ApoB-100
113
which dislipidemia has a defect in ApoC-2 and Lipoprotein Lipase
Type 1- familial chylomicronemia syndrome
elevated chylomicrons
PANCREATITIS
lipidemia retinalis
114
what enzyme catalyzes destruction of H2O2
catalase
