integrative metabolism Flashcards
muscle fiber type that is multinucleated and striated with low glycogen storage and a rich capillary blood supply
type I skeletal muscle
brain derives its specialized, complex, and VLC lipids from what linoleic and alpha linolenic acids
cerebroside, gangliosides, plasmalogens, very long chain FA
two types of cells in the brain
neurons and neuroglia (supporting cells)
types of neuroglia cells
astrocytes (blood brain barrier), oligodendrocytes (myelination), and microglia (immune function)
supply of energy for brain in the well fed state
glucose
organ that uses high and consistent rate of O2 consumption
brain
state after a meal is called …
absorptive or post prandial state
what does brain use for energy during prolonged fast
ketone bodies
importance of brain using ketone bodies for energy
it spares the glucose allowing for a reduction in gluconeogenesis and helps to spare body protein from amino acid degradation
glucose and ketone bodies enter the brain via what typeof diffusion
facilitated diffusion
glucose uses what transporter to get into the brain
GLUT 1 and 3 (not insulin dependent)
ketone bodies use what transporter to get into the brain
monocarboxylate transporter (slower than GLUT’s and upregulated during starvation)
energy storage in the brain
none really …low glycogen (insignificant) and no TAGs
why can’t FA from adipose TAGs enter into the brain
they are attached to albumin and can’t cross the blood brain barrier but dietary FA can cross using specific transporters
types of molecules that can freely cross the blood brain barrier
small uncharged molecules and non polar substances through passive diffusion; essential FA and vitamins, proteins
why do some hydrophobic drugs pass slower than expected into the brain
because they attach to albumin and hence stay longer in the blood and can’t cross the BBB (ex: phenobarbitol)
why are amino acids that are neurotransmitters blocked from entry into the brain
brain synthesizes its own neurotransmitters (separation of somatic pool from neural pool)
treatment for Parkinson’s
L-DOPA
objective of DOPA decarboxylase inhibitor given with L-DOPA
to keep levels of L-DOPA in circulation high enough so that it may cross the blood brain barrier
multi-layered membrane sheath around axons that speed action potential
myelin
two major proteins in myelin sheath
proteolipid protein and myelin basic protein
condition where there is progressive destruction of CNS myelin
Multiple Sclerosis
cause of multiple sclerosis
an autoimmune reaction but not sure what triggers it …possibly combination of a lot of things
symptoms of MS
weakness, lack of coordination, loss of vision, fatal
gaseous neurotransmitters CO and NO stimulate synthesis of…
cGMP
main excitatory neurotransmitters
Glutamate and aspartate
main inhibitory neurotransmitters
glycine and GABA
these amino acids are precursors of what neurotransmitter Tyr Trp His Glu
Tyr –> catecholamines
Trp –>serotonin –>melatonin
His –> histamine
Glu –>GABA
decarboxylation of an amino acid involves cofactor
B6 (PLP)
glutamine synthesized from…
glutamate and NH4 in astroglial cells
importance of the GABA shunt
converts GABA into a TCA cycle intermediate in few steps
epilepsy can be treated with…
GABA analogs or drugs that block GABA reuptake from synapse
benzodiazepines (valium) bind to GABA receptors. why?
potentiates GABA –> reducing anxiety
PCP (phenyclidine) is an antagonist of…
NMDA (glutamate) receptor
PE is methylated to PC by..
SAM (S-adenosyl methionine)
B12 is needed for
regenerate Met and then more SAM to form choline, needed for neurotransmitters, phospholipids
TPP needed for
PDH complex, alpha ketoglutarate DH, BCAA DH
what is deficient in Wernicke-Korsakoff syndrome (Beri Beri)
thiamine
beri beri common in what population
chronic alcoholics
causative agent of Prion disease
misfolded protein
if BSE (mad cow disease in bovine) is transmitted to humans, it is called?
new variant CJD (vCJD)
difference between PrP and PrPsc
difference in tertiary structure –conformational shape change
Alzheimer’s is a result of
inappropriate accumulation of proteolytic fragments from the beta-amyloid precursor protein hence build up of tau protein
