Flashcards in integration of metabolism Deck (36)
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1
liver
-storage fuel
-preffered fuel
-exported fuel
-glyvogen and TG
-glucose, FA, AA's
-glucoes, FA's and ketones
2
skeletal muscle at rest
-storage fuel
-preffered fuel
-exported fuel
-glycogen
-FA
3
skel muscle working
-storage fuel
-preffered fuel
-exported fuel
-doenst store in this state
-glucose
-alanine and lactate
4
adipose
-storage fuel
-preffered fuel
-exported fuel
-TG
-FA
-FA, and glycerol
5
preffered fuel of the heart
-FA
6
preferred fuel of the brain
-glucose
-ketone bodies in starvaation
7
which enzymes are out of equilibrium?
-those which are regulated
8
4 ways to regulate a step in metabolism
-allosteric inhibition or stim
-regulate the amount of enzyme present (regulate gene transcription or protein degradation, enzymes must be turned over rapidly)
-covalent modification (phosphorylation)
-compartmental separation
9
adaptive changes in regulation are done by
-regulation of the amount of enzyme
-inhibition or stimulation of gene transcription
-protein degradation or stabilization
-regulation is changed by changes in the diet
10
fructose 2,6 BP regulation
-what hormones effect it and how
-what molecules does it affect
-regulated by glucose and insulin via phosphorylation
-when F6P is phosphorylated into F2,6BP, this activates glycolysis and inhibits gluconeogenesis via PFK1 (glycolysis) and F1,6BPase (gluconeogenesis)
11
CPT 1 regulation
-what is it an example of
-what does it do?
-what regulates it?
-this is the protein that transports fatty-acyl CoA into the mitochondria for beta oxidation
-this is an example of regulation of metabolism by the compartmentalization of certain intermediates
-malonyl CoA, which is an intermediate of fat metabolism, inhibits this protein
-low energy (high AMP) triggers the inhibition of acetyl coa into malonyl coa via ACC2 and stimulates the conversion of malonyl coa into acetyl coa via MDC
12
insulin
-function
-major metabolic pathway effects
-promotes fuel storage after a meal
-promotes growth
-stimulate glucose strage as glycogen (muscle and liver)
-stimulates fatty acid synthesis and storage
-stimulates amino acid uptake and protein synthesis
13
glucagon
-function
-major metabolic affects
-mobilizes fuel sources
-maintains blood glucose levels during fasting
-activates gluconeogenesis and glycogenolysis
-activates fatty acid release from adipose tissue
14
epinephrine
-function
-major metabolic pathway affected
-mobilize fuels during acute stress
-stimulates glucose production from glycogen
-stimulates fatty acid release from adipose tissue
15
cortisol
-provides for changing requirements over the long term
-stimulates amino acid mobilization from muscle protein
-stimulates gluconeogenesis
-stimulates fatty acid release from adipose
16
characteristics of the G prtoein coupled receptor, just the receptor
-7 membrane spanning domains
-all with different extracellular domains which confer the specificity of the receptor
-all with similar intracellular domains as this is what will interact with the G protein
17
the g protein that associate with the recetor
-these are all the same for all the different types of receptors as the downstream affect is the same
18
g protein cycle
-3 subunits, alpha, bet, and gama
-alpha is bound to GDP in the inactive state
-once the receptor receives a signal, the GDP it substituted for GTP via GEF
-depending on if Galpha is inhibitory or stimulatory it will either inhibit or stimulate adenylate cyclase
-GAP then facilitates the conversion of GTP back into GDP on the alpha subunit
-alpha subunit and GDP then reassoicate with the beta and gama subunits
19
examples of diseases of the inhibitory and stimulatory alpha subunits
-inhibitory: pertussis renders the inhibitory subunit inactive therefore increase cAMP
-stimulatory: cholers renders the alpha subunits constitutively active causing increased cAMP
20
what does caffeine do?
-inhibits cAMP phosphodiesterase
-which converts cAMP into 5'-AMP, therefore leaving cAMP around for longer
21
how does cAMP stimulate PKA
-PKA is composed of two regulatory (R) subunits and two catalytic subunits
-cAMP binds to the R subunits, allowing the catalytic subunits to dissociate from the complex and become active
22
what does PKA regulate as a whole
-both glycogen breakddown and synthesis (promoting breakdown and inhibiting synthesis
-this protein has a very wide affect
-phosphorylates both phosphorylase kinase (active when phosphorylated) and glycogen synthase (inactvie when phosphorylated
23
how does Hsp90 function
-this is a chaperon protein which binds a trnascription factor when hormone is not present, keeping the transcription factor in the cytoplasm
-when hormone diffuses into the cell, it dissociates Hsp90, allowing the transcription factor that it was bound to to translocate to the nucleus and begin transcription
24
causes of starvation
-famine
-illness
-self starvation
25
stage 1 of starvation
-origin of blood glucose
-tissues using glucose
-first four hours after a meal
-exogenous
-all
26
stage 2 of starvation
-post absorptive stage
-origin of blood glucose
-tissues using glucose
-4 to 16 hours
-glycogen and hepatic gluconeogenesis
-all except the liver. muscle and fat tissue at decreased rate of using glucose
-fatty acids are provided by adipose tissue
-usually associated with an overnight fast
27
3rd phase of starvation
-gluconeogensis from amino acids
-lactate and glycerol provide blood glucose
-TAGs are mobilized to form fat for energy and glycerol for glucose production
-muscles decreaes the use of glucose and increase the use of fats
28
4th phase of starvation
-middle stage
-decrease in total glucose consumption
-decrease in gluconeogensis
-brain adapts to lower glucose levels and begins to use ketone bodies for energy
-this is when you run out of glycogen and gluconeogenesis completely takes over
29
5th phase of starvation
-glucose is still produced by gluconeogenesis and is used mainly by RBC's and the brain
-however, the signicant contributor in the brain is ketone bodies
-severe depletion of muscle mass and adipose tissue
-utilization of lactate is pretty constant as the cori cycle continues to supply the RBC's with glucose from the liver
30
