Fat Metabolism

1
1
Insulin stimulates fatty acid synthesis in liver
adipose.
2
2
Adipose
3
3
Fatty Acid Synthesis
What 8 acetylCoA ? palmitic acid
(requires energy - ATP)
(requires reducing agent - NADPH)
Why Establish Fuel Reserve
Where Liver Adipose (cytosol)
When Fed State - insulin stimulates
4
Fat as Energy Storage
4
9 Kcal g-1 vs. 4 Kcal g-1 2x
for protein/carbohydrates
Anhydrous storage in adipose 3x vs. hydrated
glycogen in liver/muscle
11 kg Fat ? 66 kg carbo/water Fat saves 55Kg
of body weight
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5
glucagon stimulates Lipase activity in
adipose.
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6
? insulin
Glycerol 3 Fatty Acids
7
Use of Fatty Acids for Energy
7
Fatty Acids transported by Serum Albumin in
blood
Both Liver Muscle can oxidize Fatty Acids.
Brain cells cant metabolize Fatty Acids they
dont cross the Blood/Brain barrier
8
8
Fat (triglycerides)
9
9
b - oxidation
What palmitic acid ? 8 acetylCoA
(requires Coenzyme A activation)
(produces 7NADH 7 FADH2)
Why Leads to aerobic ATP production
Where Liver/Muscle/Etc. (not brain)
When Fasting State -
glucagon stimulates insulin
stops
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10
Liver Fasting State
High Fat consumption ?AcetylCoAin Liver
Liver Gluconeogenesis slows Krebs Cycle
11
11
Liver Metabolism Fasting State
12
12
Ketone Bodies
13
13
from blood
Brain Metabolism Long-term Fasting State
25
75
Ketone Bodies
from blood
14
14
Liver Fasting State
15
15
Diabetes Hyperglycemia
180 mg/dl
Fed
Time
6-12 hrs
Liver Gluconeogenesis continues This can lead
to ketosis and acidosis
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16
Leptin Body Weight Regulation
Leptin is a peptide hormone secreted by
subcutaneous fat - ?fat ?leptin
Target is Hypothalmus low leptin stimulates
appetite high leptin supresses appettie
may signal UCP expression?
Is Leptin a potential treatment for obesity?
Or are people obese because they dont
respond to leptin?