🧠 LIPID METABOLISM – Colorful Handwritten Mind Map
🧠 LIPID METABOLISM
🔴 1. Fatty Acid Oxidation (β-Oxidation)
Occurs in mitochondria
Steps
1️⃣ Activation
Fatty acid + CoA + ATP
→ Fatty acyl-CoA
(enzyme: Acyl-CoA synthetase)
2️⃣ Transport
Carnitine carrier system
3️⃣ β-Oxidation Cycle
• Dehydrogenation → FADH₂ formed
• Hydration
• Oxidation → NADH formed
• Cleavage → Acetyl-CoA
Energetics (Palmitate)
7 FADH₂ → 10.5 ATP
7 NADH → 17.5 ATP
8 Acetyl-CoA → 80 ATP
✔ Total = 108 ATP
✔ Net = 106 ATP
🟠 2. Cholesterol Biosynthesis
Location: Cytosol of liver cells
Pathway
Acetyl-CoA
⬇
HMG-CoA
⬇
Mevalonate
⬇
Isoprene units (IPP + DPP)
⬇
Squalene
⬇
Cholesterol
Requirements
18 Acetyl-CoA
36 ATP
16 NADPH
Uses
✔ Bile acids
✔ Steroid hormones
✔ Vitamin D
🟡 3. Lipoproteins
Lipoprotein = Lipid + Protein
Types
Chylomicrons
Transport dietary fat
VLDL
Transport endogenous triglycerides
LDL
Transport cholesterol to tissues
HDL
Reverse cholesterol transport
Lipoprotein Degradation
1️⃣ Lipoprotein + LPL enzyme
2️⃣ Triglyceride hydrolysis
3️⃣ Fatty acid uptake
4️⃣ Chylomicron remnant formation
5️⃣ Uptake by liver
🟢 4. Ketone Bodies
Types
Acetoacetate
β-Hydroxybutyrate
Acetone
✔ Water soluble
✔ Alternative energy source
Ketogenesis (Liver)
2 Acetyl-CoA
⬇
Acetoacetyl-CoA
⬇
HMG-CoA
⬇
Acetoacetate
⬇
Acetone + β-Hydroxybutyrate
Use
During fasting/starvation
Overproduction
Ketonuria / Ketoacidosis
🔵 5. Fatty Liver
Normal liver lipid ≈ 5%
Cause
Excess triglyceride accumulation
Reasons
Increased TG synthesis
Decreased lipoprotein formation
Alcohol / metabolic disorders
🟣 6. Atherosclerosis
✔ Thickening and hardening of arteries
✔ Due to lipid deposition
Result
⬆ Risk of
Coronary heart disease
Heart attack
✅ Memory Trick for Lipid Metabolism Topics
"F C L K F A"
F → Fatty acid oxidation
C → Cholesterol synthesis
L → Lipoproteins
K → Ketone bodies
F → Fatty liver
A → Atherosclerosis
