MCP Flashcards
clinical correlation: rare, inherited, mutations that encode sterolin transporters, increased phytosterols in blood and tissues, tuberous xanthomas, coronary atherosclerosis
sitosterolemia
clinical correlation: low bile salts or high cholesterol, treat with laproscopic cholesystectomy
cholelithiasis
bile (acids/salts) are better detergents because they are more amphipathic
conjugated ionized bile salts are better detergents
bile salts lost in feces daily is (more than/less than/equal to) the bile salts made daily by liver
equal to
how do statins lower cholesterol
they are structural analogs of HMG and competitively inhibit HMG CoA R-ase, inhibiting cholesterol synthesis
RDS in cholesterol synthesis (substrate, product, enzyme)
HMG CoA to mevalonate by HMG CoA Reductase
8 steps from mevalonate to cholesterol. Number the carbons in each intermediate
mevalonate has 6C > 5PPmevalonate has 6C > IPP has 5C >DMPP has 5C > GPP has 10C > FPP has 15C > squalene has 30C > lanosterol has 30C > cholesterol has 27C
in the synthesis of cholesterol, what is the purpose of release of pyrophosphate
makes reactions irreversible
in the synthesis of cholesterol, what is the purpose of phosphorylation
makes intermediates more soluble in water
which intermediates in synthesis of cholesterol need carrier proteins
squalene, lanosterol, cholesterol
(insulin/glucagon) upregulates HMG CoA R-ase activity
insulin (HMG CoA R-ase=synthesis of cholesterol=anabolic)
(phosphorylation/dephosphorylation) INACTIVATES HMG CoA R-ase
phosphorylation
high cholesterol (increases/decreases) HMG CoA R-ase activity
decreases (binds sterol sensing domain on the enzyme which triggers ubiquitination>proteasomal degradation, also binds sterol sensing domain on SCAP so SCAP-SREBP2 can’t migrate to golgi to cleave SREBP to increase txn)
Apo _: Structural protein (HDL); LCAT activator; Involved in RCT; ligand for ABCA1 and SR-B1
A-I
Apo _: structural protein HDL, inhibits LCAT,
A-II
Apo _: structural protein (VLDL, LDL), VLDL assembly, LDLR binding, one copy for each VLDL
B-100
Apo _: structural protein (LDL, VLDL), VLDL assembly, LDLR binding, produced in intestine, chylomicron metab
B-48
Apo _: can be exchanged freely among lipoprotein particles, important for TG metab bc they interfere with recognition of ApoE by LP receptors or displace ApoE from lipoproteins
C’s
Apo C (I/II/III): LCAT activator
I
Apo C (I/II/III): lipoprotein lipase activator
II
Apo C (I/II/III): inhibits lipoprotein lipase
III
Apo E (2/3/4): normal
3 edited
Apo E (2/3/4): risk for type III hyperlipidemia
3
Apo E (2/3/4): Alzheimer’s
4
Apo _: modulates thrombosis/thrombolysis
(a)
(DRI/RDA): defined as the amount sufficient to meet the nutrient requirement of 97-98% of healthy individuals in a given group
RDA = recommended daily allowance, varies for different populations
two water soluble vitamins
B and C
deficiencies arise more rapidly with (water/lipid) soluble vitamins
water solulbe, since they are excreted efficiently
Vit _: functions in visual cycle, antioxidant, retinoic acid acts as a hormone
A
Vit _: deficiency causes night blindness, xeropthalmia, follicular hyperkeratosis, anemia (despite normal iron intake), poor growth in children, increased susceptibility to cancer
A
three groups susceptible to Vit A def
poor, malnourished, premature babies
Vit _: functions in maintaining bone, calcium homeostasis, acts as a hormone
D
Vit _ def: rickets, osteomalacia, increased susceptibility to breast and other cancers, diabetes, and infection
D (toxic levels of Vit D can lead to high levels of calcium and bone loss–rare)
three groups susceptible to Vit D def
poor, elderly, alcoholics
Vit _: functions in localization of enzymes required for blood clotting, helps catalyze add’n of gamma-carboxyglutamate to clotting enzymes
K
Vit _ def: results in easy bruising, bleeding, hemorrhage
K
four groups susceptible to Vit K def
NEWBORN INFANTS, patients on long term antibiotics, elderly, pts with defects in fat absorption
why are newborns so susceptible to Vit K def
lack intestinal bacteria that makes vitamin K, and deficiency can lead to brain bleed. Vitamin K shot now given at delivery (prophylactic measure)
why are people on long term antibiotics susceptible to Vit K def
antibiotics kill intestinal bacteria that make vit K
Vit _: functions as antioxidant, protects membranes from damage, prevents oxidation of LDL
E
Vit _ def: CVD, neurological symptoms
E
Vit _: cofactor for oxidases
involved in collagen
formation, required for synthesis of steroids in stress
response (response to
trauma), aids absorption of iron, has antioxidant
activity
C
Vit _ def: mild causes bruising and immunocompromise, severe causes scurvy
C
name disease: decreased wound healing, osteoporosis, hemorrhage, anemia, fatigue
scurvy
two groups susceptible to Vit C def
smokers, ppl w/ poor diet
severe stress or trauma rapidly reduces serum Vit _
C
In addition to smoking, long-term treatment with aspirin,
oral contraceptives, and corticosteroids can decrease
serum vitamin _
C
corkscrew hairs and pinpoint hemorrhages are characteristic of ____ (dz)
scurvy, also severe periodontal dz
name B1
thiamine
name B2
riboflavin
name B3
niacin
name B5
pantothenic acid
name B6
pyridoxine
name B9
folate
name B12
cobalamin
name the hematopoietic B vitamins (two)
B9 and B12
name the energy releasing B vitamins (six)
B1, B2, B3, biotin, B5, B6
symptoms of def in energy releasing B vitamins show up first where
in rapidly dividing tissues–Nervous system also affected because of high
energy demand:
Peripheral neuropathy—tingling of extremities
Depression, confusion
Lack of coordination
Malaise
Vit _: required cofactor for several enzymes in energy metabolism, critical in nervous system
B1 (TPP)
name disease: • Moderate/severe thiamine deficiency, most commonly seen in chronic alcoholics • Characterized by mental disturbance, unsteady gate, and uncoordinated eye movements • Occasionally congestive heart failure
Wernicke-Korsakoff syndrome
name disease: Very Severe thiamine deficiency: 19th century
Japan- switch to polished rice induced disease
Beri Beri
Vit _: Precursor of FAD and FMN, key coenzymes for redox reactions involved in energy metabolism
B2
Vit _ def: —rash around nose, inflammation of mouth and tongue, burning and itchy eyes, light sensitivity
ariboflavinosis B2
Vit _: Precursor of NAD and NADP coenzymes important in redox reactions of energy metabolism • Given to patients with hyper-cholesterolemia or hypertriglyceridemia (high doses)
B3
Vit _ def: pellagra
B3 niacin
name disease: dermatitis,diarrhea,
and mental symptoms
(confusion, memory
loss, mania)
Pellagra
group susceptible to B3 def
People with corn or
millet based diets
Vit _: coenzyme for several carboxylases. Def is rare but can be caused by eating a lot of raw eggs
biotin
Vit _: Required for the synthesis of CoA CoA is a coenzyme for up to 70 different enzymes Required for TCA cycle and metabolism of all fats and proteins
B5
Vit _: Required for glycogen
breakdown,and
synthesis of GABA
and heme
B6. Also precursor of pyridoxal phosphate PLP enzyme cofactor
group susceptible to B6 def
patients treated with TB drugs
Vit _ def: Mild—irritability, nervousness, depression Severe—peripheral neuropathy, convulsions, decreased glucose tolerance, hyperhomocysteinemia (cardiovascular risk), anemia
B6
Vit _: functions as precursor of THF, co enzyme involved in generating precursors for DNA and protein synthesis
B9 folate
Vit _ def: neural tube defects in newborns of deficient mothers
–macrocytic anemia, hyperhomocysteinemia (cardiovascular risk)
B9 folate
five groups susceptible to folate B9 def
pregnant women, elderly, alcoholics, patients with long-term drug treatments, genetic polymorphisms in folate metab
folate supplementation during pregnancy can prevent
neural tube defects
Vit _: functions as coenzyme in methionine synthesis and in conversion of methylmalonyl CoA to succinyl Coa, needed in folate metab
B12 cobalamin
Vit _ def: pernicious megaloblastic anemia with demyelination
B12 cobalamin (need intrinsic factor)
three groups susceptible to B12 cobalamin def
elderly, patients with malabsorption dz, long-term vegetarians
mineral _: functions as a major component of bone, signaling, coagulation, muscle contraction, neurotransmission
calcium
mineral _ def: muscle cramps, osteoporosis. severe: rickets
calcium
three groups susceptible to calcium def
children, adult women, elderly
mineral _: essential for enzymes using ATP as substrate, present at high levels in bone
magnesium
mineral _ def: weakness, tremors, cardiac arrhythmia
magnesium
two groups susceptible to magnesium def
alcoholics, patients taking diuretics/severe vomiting and diarrhea
mineral _: major component of bone, constituent of nucleic acids and membrane lipids, required in all energy producing reactions
phosphorus