Biochem Flashcards
functions of liver
maintain blood glucose
synthesize ketones from Acetyl CoA when switch to lipolysis
synthesize fatty acids, convert to TGs and release as VLDLs
requirements for liver
absorptive state: glucsoe and aa for energy
post-absorptive state: lactate, glycerol and aa for gluconeogenesis
functions of adipose tissue
take up fatty acids and convert to TG for long term storage
release FA into circulation
requirements for adipose tissue
glucose to produce glycerol phosphate for esterification of fatty acids
switch to fatty acids during post-absorptive
functions resting skel mm
release aa into blood
requirements for resting skel mm
absorptive state: glucose for oxidation and glycogen stores, aa for protein synthesis
post absorptive: fatty acids and ketones for energy
metabolism in fast twitch active skel mm
anaerobic glycolysis from glycogen
metabolism in slow twitch active skel mm
oxidative metabolism of glycogen
after several hours, switch to lipolysis
muscle contraction activates what metabolic pathway
TCA cycle
increase in Ca
increase in ADP
decrease in NADH and NAD+
what occurs in high intensity exercise
need for ATP exceeds mitochondrias capacity for oxidative phosphorylation
an increased NADH/NAD+ ratio directs what pathway
pyruvate into lactate
at intracellular pH what does lactic acid dissociate into
lactate and H+
decrease in pH causes what systemically
pain and fatigue
what is generated in low intesnsity exercise
glucose to CO2
increase in ADP stimulates what
isocitrate dehydrogenase
ETC to form NAD+ and FAD
decrease in NADH stimulates what
isocitrate dehydrogenase and malate dehydrogenase
increase Ca concentraiton causes what
stimualtes isocitrate dehydrogenase
stimulates alpha-ketoglutarate dehydrogenase
what happens when NADH/NAD ratio increases
citrate inhibits acetyl CoA entering TCA cycle
NAD+ is allowed to increase
what is rate limiting in aerobic metabolism
O2, the final electron acceptor
What TCA enzyme is in inner mitochondrial membrane and transfers electrons directly to CoQ within ETC
succinate dehydrogenase
what is the vitamin precursor of FAD
riboflavin
what is the vitamin precursor of NAD+
niacin
what is the vitamin precursor of CoA
pantothenate
increased transcription in myocytes leads to adaptive changes where
TCA cycle enzymes: increased #, decreased lactate production from pyruvate
ETC components: increased #
mitochondria: increased # size and productivity
increased vasodilatory capacity and lymphatic drainage from exercise can cause what metabolic changes
increased metabolites and decreased lactate
what will be increased in starvation
glucagon and epinephrine
what is main mech for metabolism in starvation
lipolysis to save proteins for essential functions
ACetyl CoA produced and converted to ketones
what does a muscle use for E in starvation
fatty acids
the brain uses what for E in starvation
ketones and glucose
what do RBCs use for E in starvation
glucose
when does amrnorrhea develop in response to dec body weight
when fat content is below 22% of normal
from reduced LH and FSH production
when does death by starvation occur
when 40% ideal body weight lost
30-50% body protein lost
70-95% body fat stores are lost
what decreases in starvation
depletion of muscly glycogen stores
depletion of adipose tissue TG
depletion blood glucose from liver glycogen
Sx vitamin deficiency
fatigue, nausea, loss of appetite
muscle pain from glycolysis as primary source of pain
what causes muscle pain in anorexic patient
glycolysis
whhat is riboflavin
vitamin precursor of FAD and FMN
major coenzyme in all tissues
niacin is a precursor to what
NAD+
niacin can be synthesized from what
tryptophan
what is required for alpha ketoglutarate dehydrogenase
thiamine
what is a precursor to CoA
pantothenate
what are Fe-S centers
in ETC, non-heme iron proteins that are affected by Fe deficiency anemia
what causes fatigue in iron deficiency anemia
the loss of Fe-S centers in ETC
