Sept 24 bioch lectures
Important concepts
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4 things the liver will do in a fasting state
The liver will
1. Release glucose in the blood from its glycogen
stores (glycogenolysis)
2. Synthesize and release in the blood
‘new’ glucose (gluconeogenesis)
3. Synthesize and release in the
blood ketone bodies (ketogenesis)
4. Use exclusively faty acid
oxidaton (vs ketone bodies and glucose) to maintain its
functon
Fat cell view
what hormone makes the switch from fed to starving state actions
glucagon adrenaline epinephrine
3 enzymes of adipose lipolysis
which is rate limiter
- ATGL (adipose triacylglycerol lipase)... RATE LIMIT
- HSL (hormone sensitive Lipase)
- MAGL (monoacylglycerol lipase): NOT hormonally reg
Regulation of Lipolysis
steps from basal to stimulated
PKA phosphorylation: CGI-58 gets unsequestered via phosphorylation of perilipin
ATGL activated
HSL also phosphorylated, increased activity and translocates to the lipid droplet to act
Insulin and lipolysis
how many FA at a time can albumin carry
adipose tissue fuel options
many
can send glycerol on to make glucose
fa to tissues for ox
FA into tissues during fasted state
two sources
important enzyme
two organelles and way in each
carnitine shuttle
Fatty acids shorter than 10 carbons ...
FA oxidation process (4 steps, RL enzyme, final products)
side by side of fa oxidation v synth
diff lengths of acyl coa dehydrogenases
MCADD
most common
high levels of acyl carnitines of specific lengths will diagnose
Energy from stearate oxidation
oxidation of odd chain FA
Regulation of mitochondrial FA ox
FA oxidation in peroxisomes
diff enzymes
not atp linked, so results leave as acyl carnitines of FFA, not acyl coa-->shortened FA and acyl carnitines go to mitochondria to be completed
Adrenoleukodistrophy
important concepts FA ox lecture
Important enzymes
- ATGL (adipose triacylglycerol lipase)
- HSL (hormone sensitive Lipase)
- MAGL (monoacylglycerol lipase)
- Acyl-CoA synthetase
- Carnitine Palmitoyltransferase I and II, Carnitine Acylcarnitine translocase
- Acyl-CoA dehydrogenase
- Diff lengths
- Propionyl coa one
- Methylmalonyl-CoA mutase, Vitb12
Important molecules/concepts
- Glucagon, adrenaline, and epinephrine play a key role in driving the metabolic switch from fed to fasted (nothing else is needed from slide ‘fasted state metabolism overview”
- CGI-58, perlipin
- PKA
- Albumin
- Adipose tissue fuel sources
- ABCD1 transporter
- Carnitine Shuttle
- Carnitine
- , acylcarnitine
- Acyl CoA
- Fatty acids shorter than 10 c
Important Processes
- Lipolysis regulation
- Insulin reg
- Carnitine shuttle
- Beta oxidation
- Odd chain FA ox
- Regulation of
Structures
- Fat cell view
Diseases
- MCAD deficiency
- Adrenoleukodistrophy
important concepts from ketone body lecture
Enzymes
- Thiolase
- HMG-CoA synthase
- HMG-CoA lyase
- D-b-hydroxybutyrate dehydrogenase
Molecules
- Beta hydroxybutyrate
- Acetoacetate
- acetone
Processes
- Ketogenesis
- Overview of ketone metabolism
- Utilization of ketone bodies for energy by extra hepatic tissues
the three ketone bodies and their structures
image of ketone body w other processes
preferrential if atp high
ketogenesis
steps
important enzyme
what causes it
location
rate reflects what
what can it stimulate
soo, if have a lot of acetyl coa AND lots of ATP, this is likely, bc then it means are in FA ox and need to make more energy.. also would have a lot of nadh but FROM fa ox. (use nadph to build)
blood ketone concentrations reflect...
ketone body reg
helps to prevent muscles from making glucose... alternative fuel that keeps muscles in tact
overview of ketone metabolism
utilization of ketone bodies by extra hepatic tissues
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