Lipolysis Flashcards
What mobilizes the FA from triglycerides?
Lipases
Fatty acid oxidation bring the FA to where?
The mitochondria
Fatty acid oxidation activates the FA from?
acetyl CoA synthetase and pyrophosphatase
How is a FA transported into the matrix of the mitochondria?
By CPT and carnitine
Where is the FA transported to?
Then matrix of the mitochondria
FA oxidation makes what?
Makes ATP
FA oxidation enters the aerobic system(krebs and ETS) by multiple what?
Dehydrogenases
Hydrolysis of triglycerides is converted from glycerol to FA by what?
Lipases
Lipases TAG goes to DAG by what?
ATGL
Lipases DAG goes to MAG by what?
HSL
Lipases MAG goes to LCFA and glycerol by what
MGL
What are TAG broken down by? And what does it trigger?
Epinephrine and glucagon
And triggers the action of three lipases on a lipid droplet
What are the results of epinephrine and glucagon?
Low energy
Low blood sugar
What do 3 lipases on a lipid droplet trigger?
Lipases turn triglycerides into free fatty acids
Do hormones activate second messengers? And if they do what messengers are stimulated?
Yes, stimulates adenylyl Cyclades
What stimulates adenylyl Cyclase?
cAMP
AMP kinase PKA
What does PKA stimulate?
Stimulates Lipolysis in fat cells
By breaking down a TAG what does it activate?
Activated HSL hormones sensitive lipase
What is HSL activated by?
Phosphorylation
DAG to MAG
AMP stimulates
Glut4 Glycogen breakdown Glycolysis LPLm activation Fat Burning
AMP inhibits?
Glycogen synthesis
TAG synthesis
Cholesterol synthesis
FA synthesis
What does insulin do in breaking down TAG?
De phosphorylates HSL
inhibits ATGL
What is the fate of glycerol?
Transported in blood to the liver
What is glycerol transported by?
Phosphorylated to glycerol 3 phosphate
Glycerol 3 phosphate does what?
TAG synthesis
Phospholipid synthesis
DHAP glycolysis and gluconeogenesis
Glycerol 3 phosphate is transferred to dihydroxyactone phosphate by what enzyme?
By glycerol 3 phosphate dehydrogenase
What is a free fatty acid transported in?
Transported in the blood
Free fatty acid in the blood is bound to what and sent to where?
Bound to serum albumin
Sent to target tissues skeletal heart renal cortex and is a fuel source
How many free fatty acids can albumin carry?
Can army 10 free fatty acids pet protein monomer
What does a FA enter in order to degrade?
Enters the muscle
When a FA is activated what does it turn in to?
Acyl CoA
FA degradation what does it specifically enter?
The mitochondria
Where is a FA in degradation oxidized at?
In the mitochondria OHOT
A FA entering the muscle must be chaperoned by a? And escorts it to where?
Protein and is escorted to the surface of the mitochondria
Activation of the FA happens how?
Attaching a coenzyme A to the FA Snd crating Acyl CoA
After the coenzyme A is attached to the FA and creates Acyl CoA the enzyme is Acyl CoA synthetase it is about to enter what?
The mitochondria
Activating the FA is driven by what?
Driven by ATP
What is the location that the FA activation takes place?
The outer mitochondrial membrane
By activating the FA it does what?
Links between CoA and the fatty acid
What is consumed in the process of activating the FA?
ATP
ATP is what
AMP + PPi
PPI is
2Pi + energy
Pyrophosphotase
Pyrophosphotase is what to make the reaction irreversible
Is hydrolyzes
This is common in biosynthesis
After hydrolization we do what?
Oxidation
What does the CPT (carnitine palmitoyltransferase complex) consists of?
CPT I
Acylcarnitine translocase
CPT II
What is the CPT complex responsible for?
Transport of LCFAs
What is CPT I considered?
The rate limiting step
What’s another name for acylcarnitine translocase?
Carnitine acyltransferase
CPT complex is reversible inhibited by?
Malonyl CoA (first committed step in FA synthesis)
CPT complex is kept at a neutral pH optimum and is inhibited when?
From pH decrease 7.0 to 6.8
in the cytosol is where the BLANK are?
the regulatory sites
lactic acid or PH
where are the regulatory sites?
on the CPT I
What four steps does Beta oxidation refer to?
these steps occur prior to having fat enter the aerobic system Oxidation Hydration Oxidation Thiolysis
During the oxidation phase what occurs?
Acyl CoA converted to Trans Enoyl CoA by Acyl CoA dehydrogenase and loses a FAD to go to a FADH2
During the hydration phase what occurs?
trans enoyl CoA is converted to L-3 hydroyacyl CoA by enoyl CoA hydrotase and water is added
What occurs during oxidation II phase?
3 hydroxyacyl CoA is converted to 3 ketone CoA by L-3 hydroxyacyl CoA dehydrogenase and NAD+ is lost to go to NADH + H+
During the thiolase phase what occurs?
3 ketoacyl CoA is converted to Acyl CoA (minus 2) or Acetyl CoA by B ketothiolase while CoA-SH is added to the reaction
What does oxidation produce? and by what?
produces a double bond and FADH2
Dehydrogenase
By adding water (a hydroxyl group) and removing a double bond what is the enzyme?
hydratase
What does the second oxidation turn the hydroxyl group into?
into a carbonyl group
dehydrogenase
Oxidation and hydration in the krebs cycle is what?
Succinate to Fumarate by:
Succinate dehydrogenase
and fumarate to malate by:
Fumarase
In the krebs cycle what is Malate converted to and by what?
converted to oxaloacetate and by malate dehydrogenase
What are FADH2 and NADH?
both are products that got to the ETS
What is Acetyl CoA? what does it enter? what does it produce?
is a product
enters the krebs cycle
produces reduced coenzymes FADH2 and NADH to be sent to ETS
what happens to the Acetyl CoA each time you run the B-Oxidation (OHOT)?
is two carbons shorter each time you run the B-oxidation OHOT
unsaturated FA degradation?
many of the reactions are the same
two additional enzymes are required
what are the two additional additional enzymes required?
reductase and isomerase
what two things are the same at getting into the matrix?
translocation and activation
What occurs during oxidation?
Acyl CoA to 2,4 dienoyl CoA by Acyl CoA dehydrogenase
FAD enters and leaves as FADH2
What occurs during reductase?
2,4 dienoyl CoA to cis enoyl CoA by 2,4 dienoyl CoA reductase
NADPH + H+ enters and leaves as NADP+
What occurs during isomerase? (new step)
cis enoyl CoA to trans enoyl CoA by isomerase
What occurs during hydration?
trans enoyl CoA to L-3 hydroxyacl CoA by enoyl CoA hydratase and water is added
What occurs during Oxidation II?
L-3 hydroxyacyl Coa to 3 ketoacyl CoA by L-3 hydroxyacyl CoA dehydrogenase
NAD+ enters and leaves as NADH + H+
What occurs during thiolase?
3 ketoacyl CoA to acyl CoA or Acetyl CoA by beta ketothiolase
CoA-SH enters in
what fats require one or two extra enzymes?
polyunsaturated
what are odd numbered double bonds? how do they get degraded?
isomerase
degrade two by two just like even chain FA
what are even numbered double bonds? how do they get degrade?
reductase and isomerase
they get degraded two by two just like odd chain FA
what is the difference between odd and even chain FA?
Odd chain FA are let with propionyl CoA
what is propionyl CoA converted to?
succinyl CoA
this conversion is common in converting AA into TCA intermediates
what is required for FA oxidation regulation?
energy required
what are the energy requirements?
Liver
high NADH/ NAD+ ratio
high concentration of acetyl CoA
what does the energy requirement of the liver do?
need energy B xidation in mitochondria
do not need energy form TAG and phospholipids cytosol
what does the energy requirement high NADH/NAD+ do?
signals high energy
inhitbits 2nd oxidation step (3 hydroxacyl CoA dehydrogenase?
what does concentration of acetyl CoA do?
inhibtis thiolase
what is carnitine shuttle and what does it do in the FA oxidation regulation?
is the rate limiting step
FA in mitochondria committed to B oxidation
what does glucose do in FA oxidation regulation?
increased glucose increases malonyl CoA
inhibits CPT I inhibits B oxidation
what does AMP do in FA oxidation regulation?
exercise or fasting increases concentration of AMP
AMPkinase
stimulate FA oxidation inhibits FA synthesis
regulation and stimulation
hormones
epinephrine norepinephrine glucagon
AMP (cAMP)
low energy
regulation and inhibition
hormone insulin high glucose high energy high NADH/NAD+ malonyl CoA
what are the key enzymes in FA oxidation?
lipases
acyl CoA cynthetase
acyl Coa dehydrogenases
lipases are
free fatty acids from triglycerides
acyl CoA sythetases
activates the FA for transport into the mitochondria
Acyl CoA dehydrogenases
first enzyme of OHOT (B oxidation)
oxidizes acyl CoA
FA oxidation (has 7 things):
mobilizes the FA from Triglyceride- lipases
bring the FA to the mitochondria
activate the FA- acyl CoA synthetase and pyrophosphatase
transport the FA into the matrix of the mitochondria- CPT and carnitine
Beta oxidation- OHOT (acyl CoA Dehydrogenase)
enter the aerobic system(krebs ETS)- multiple dehydrogenases
makes ATP
HSL is strongly inhibited by>
insulin
ATGL is elevated in
type II diabetics
HSL exhibits a 10 fold higher specific activity for
DAG from TAG
