module 14- metabolic integration Flashcards
3 stores of fuel
glycogen, triacylglycerol & protein
where are glycogen stores present
liver & muscle, 1 day of energy
where are triacylglycerol stores present
adipose tissue & liver
where are proteins stored
muscle, 20 days of energy
liver function
produce fuel from nutrients in blood, act as glucose sensor
FA taken up by the liver can be broken for energy through ( )
b-oxidation
what is the major fuel used by the liver to meet its own energy needs
FA
T or F: GLUT2 in liver has high Km for glucose
T
T or F: glucose uptake in the liver is increased when glucose levels are
high
glucokinase
hexokinase isoform, only active when glucose levels rise
what does glycogen phosphorylase a do in the liver
degrades glycogen
muscle energy needs at rest vs exertion
rest- FA
exertion- glucose, produces lactate, muscle protein
what is the largest storage compartment
adipose tissue
how long can glycogen vs triacylglycerol stores provide energy for
glycogen- 24 hours
TAG- several months
where does glycerol-3-P for TAG synthesis in adipose tissue come from
glycolysis
what % of glucose does the brain consume?
60%
what does the brain use for fuel under normal conditions?
glucose, or ketone bodies if sparse
why can the brain not use FA as energy?
bound to albumin, cannot cross the blood brain barrier
what does insulin stimulate? how?
glucose uptake into adipose & muscle using translocation
how does insulin increase glucose uptake in the liver
stimulating glucokinase
insulin stimulates glycogen synthesis in liver & muscle by activating ( ) & inhibiting ( )
glycogen synthase, glycogen phosphorylase
glucagon effect on liver & adipose reflects the role to () blood glucose level so brain has adequate supply
increase
how does glucagon stimulate FA mobilization
stimulating hormone-sensitive lipase
what 2 things do glucagon inhibit
glycogen synthesis & glycolysis
what is the 1 thing insulin inhibits
lipolysis
what are the 2 things epinephrine inhibits
glycolysis in liver & glycogen synthesis
3 things that occur during the early phase of starvation
insulin drops, glucagon levels rise & gluconeogenesis & glycogen breakdown is stimulated from increase glycogen
what 2 things occurs during mid phase starvation
muscle protein starts degrading & glucagon stimulates ketone body synthesis in the liver
brain derives 1/3 of its energy from ketone bodies
what 3 things occurs during the late phase of starvation
adipose tissue provides most of energy, muscle protein degradation slows & ketone body production increases
brain derives 2/3 of energy from ketone bodies
type 1 diabetes
insulin-dependent, birth
type 2 diabetes
insulin-independent, later in life
type 1 diabetes have ( ) blood glucose levels but act body acts like they are ( )
high, low
starvation in the midst of the plenty
type 1
lack of glucose uptake in type 1 results in reduction of
glycerol-3-P
what type of diabetes is ketoacidosis seen with ( ) and what does it do
type 1, excess ketone bodies form acetone
T or F: diabetes causes increased urination but starvation does not
T
diabetes mellitus
honey sweet urine
polydypsia
excessive thirst
ketogenesis
ketone bodies are synthesized in liver from acetyl CoA
T or F: liver can convert FA to glucose via gluconeogenesis when blood glucose levels are low
F
