metabolism and insulin Flashcards
intermediary metabolism: explain the endocrine regulation of intermediary metabolism; summarise the principle metabolic pathways for carbohydrates, proteins and fats and explain their hormonal regulation; explain how metabolism changes in the fasted, fed and insulin deficient states
define intermediary metabolism
intracellular process by which nutritive material is converted into cellular components
how and why are adipocytes in central circulation different to those in the limbs
central circulation anatomical sites have greater possibility of changing metabolism, rapid turnover and more active in endocrine perspective because different circulation: heart → gut → liver → somatic circulation
what part of lipids can be used to make glucose
glycerol - cannot use non-esterified fatty acids as enter TCA cycle directly (acetyl CoA); after fast, 25% of HGO supported by hepatic gluconeogenesis
what substrates can the brain use
glucose, ketone bodies
why doesn’t the brain use fatty acids
enzymes breaking down fat in organ made of fat
fasted state: characteristics
low insulin:glucagon ratio, low [glucose], increase [NEFA], low [amino acid] when prolonged
fasted state: metabolic pathways
increase proteolysis, lipolysis and HGO from glycogenolysis and gluconeogenesis; muscle to use lipid, brain to use glucose, later ketones; increase ketogenesis when prolonged
fed state: characteristics
stored insulin released, then second phase; high insulin:glucagon ratio
fed state: metabolic pathways
stop HGO, increase glycogen production, decrease gluconeogenesis, increase protein synthesis, decrease proteolysis, increase lipogenesis
