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if a molecule is "saturated" what does that mean?
it contains no double bonds
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in the well-fed state, the body will store ___ in the adipose tissue.
triglycerides (TGs)
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enzymes that catalyze the hydrolysis of stored TGs
lipases
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during fasting ____ provides energy
adipose tissue
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how does low blood glucose trigger mobilization of TGs?
through epinephrine & glucagon via adenylyl cyclase
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what do FAs bind to in the blood stream?
albumin
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where does albumin transfer FAs to? (3)
- 1) skeletal muscle
- 2) heart
- 3) renal cortex (kidneys)
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1st stage of FA oxidation
 -oxidation
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how many times does -oxidation occur?
the cycle repeats 2 carbons at a time until only acetyl-CoA remains
ex: 14C FA undergoes 6 cycles
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where does b-oxidation occur in the cell?
mitochondria
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signals liver, skeletal muscle, & adipose tissue that blood glucose is higher than necessary
insulin
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carries message that blood glucose is too low
glucagon
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body response to insulin
glucose is taken up from the blood into cells & converted to glycogen & TGs
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body response to glucagon
produce glucose through glycogen breakdown & gluconeogenesis, & by oxidizing fats to reduce use of glucose
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True or False - Insulin release increases fatty acid synthesis?
true
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key enzyme involved in FA synthesis
acetyl-CoA carboxylase
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key enzyme involved in glycogen breakdown
glycogen phosphorylase
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glucogenic liver
liver in the fasting state
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lipogenic liver
liver in the well-fed state
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during starvation, how does the body compensate for the decrease in free CoA needed for b-oxidation?
produce & export ketone bodies
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3 important ketone body molecules
- 1) acetone
- 2) acetoacetate
- 3) D--hydroxybutyrate
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where do reactions of ketone body formation occur?
matrix of liver mitochondria
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what uses ketone bodies as fuel?
extrahepatic tissues
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increased ketone bodies are found in... (2)
- 1) severe starvation
- 2) untreated diabetes
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major sterol in animal tissue
cholesterol
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sterols are precursors of what significant biological molecules? (2)
-
accumulation of cholesterol in blood vessels, leading to obstruction/reduction of blood flow
atherosclerosis
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narrowing of the arteries to the heart via atherosclerotic plaques, often leads to heart attack
coronary heart disease
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rate limiting step during cholesterol synthesis
HMG-CoA -> mevalonate (by HMG-CoA reductase)
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HMG-CoA activator
insulin
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HMG-CoA inhibitors (2)
- 1) glucagon
- 2) cholesterol (neg feedback)
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mechanism of statin drugs
- mevalonate mimics
- initiate negative feedback to inhibit HMG-CoA reductase -> less cholesterol synthesized
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