Chapter 19 Regulation of Metabolism Flashcards
metabolism
all of the chemical reactions in the body
subdivisions of metabolism
anabolism (energy storage)
catabolism (energy liberation)
absorbtion time of an average meal
4h
energy reserves
glycogen and fat
formation of glycogen and fat
glycogenesis and lipogenesis
what controls the use of reserves
hormones
two functional states that provide energy for cellular activity
absorbtive state
postabsorbtive state
absorbtive state
“feasting” (sclemmen)
when ingested nutrients enter the blood from the GI tract during 4h following a meal
postabsorbtive state
"fasting" after absorbtive state when GI tract is empty of nutrients and body´s own stores supply energy insulin secretion decreases glucagon secretion increases
hormones that controle the states
glucagon and insulin
glucagon
secreted by alpha cells of islets of Langerhans
increased secretion during postabsorbtive state when blood glucose is low
what does glucagon stimulate
breakdown of glycogen
production of glucose
insulin
secreted by beta cells of islets of Langerhans
increased secretion during absorbtive state when blood glucose is high
what does inulin do
synthesis of energy reserves
carbohydrates during absorptive state
absorbed into glood from GI tract as monosaccharides
proteins during absorptive state
absorbed into glood from GI tract as AAs
fat during absorptive state
absorbed into lymph as chylomicrons, and lymph drains into systemic veins
glucose
body´s major energy source during absorptive state
what happens to glucose during aborptive state
catabolized to CO2, H2O and energy
conversion to glycogen
transformation to fat
synthesize triglyceride
Lipids in absorptive state
together with glucose transformed into triglcerides to be stored
provides energy
excess of cholesterol from chylomicrons
can lead to atherosclerosis
amino acid in absorptive state
used to synthesis proteins
deaminated (amino group used to secrete urea, rest is catabolizes for energy)
protein catabolism
breakdown of proteins into AAs
ways that maintain blood glucose for energy and CNS activity
glycogenolysis (breakdwon of glycogen)
gluconeogenesis (synthesis of glucose using AAs)
glucose sparing (use of free fatty acids from lipolysis for energy)
ketogenesis (synthesis of ketone from fatty acids)
