Lipid Metabolism Flashcards
(24 cards)
What do lipids do?
Storage for fuel
Structural components
Participate in signal transduction
Provide with insulation, creates heat and fat digestion
Source of Fatty Acid synthesis is
Dietary carbs. Not F.A because that would suppress synthesis.
Describe the 3 phases of Fatty Acid Synthesis
Phase 1: Cytosolic entry to acetyl coa
Phase 2: Generation of Malonyl Coa
Phase 3: Fatty acid chain formation
What is special of Malonyl Coa?
Its a substrate for F.A synthase but also a regulator that inhibits F.A degradation.
Rate limiting step of F.A synthesis
Acetyl Coa Carboxylase
Fatty Acid Synthase structure
Multi enzyme complex with two identical dimers. Each dimer has identical 7 enzymes with a special ACP: Acyl carrier protein
Phase 3 of F.A synthesis reaction:
1 acetyl coa + 7 malonyl coa + 14 NADPH = Palimitate + 14 NADP + 8 coa
Elongation of F.A is completed in what organelle?
Smooth endoplasmic reticulum (2 carbons at a time)
Unsaturated or double bonds can not be added beyond carbons #__ and #__ in F.A
9 or 10
Omega 6 F.A
Linoleic acid
Omega 3 F.A
Linolenic acid
Linoleic acid makes
Arachidonic acid
Linolenic acid makes
EPA and DHA
What are the 4 lipases of TAG breakdown?
ATGL
HSL
LPL
MAG
What activates TAG breakdown?
Glucagon or Epinephrine
4 Enzymes of Carnintine shuttle
Fatty Acyl CoA Synthetase
Carnitine palmitoyltransferase
Carnitine acylcarnintine translocase
Carnitine palmitoyltransferase II
Name major type of ACAD
Medium chain Acyl Coa Dehydrogenase
What is the most important enzyme of B oxidation?
ACAD: Acyl Coa Dehydrogenase
Metabolic defects of fatty acid oxidation stems from two notable pieces of the process?
Carnitine shuttle
ACAD
MCAD Deficiency
Cant break down MCFA
Need a lot of glucose in diet
Ketone bodies
Acidic and water soluble
Occurs when body is not undergoing any glucose metabolism esp when not eating glucose. Releasing lots of FA
What are the 3 ketone bodies?
Acetoacetate
B-Hydrobutyrate
Acetone
Where are ketone bodies produced?
Liver but specifically in mito matrix. Provides energy to brain during starvation, muscles when fasting and kidneys.
Difference between physiological ketosis and pathological acidosis
Physio is mild to moderate to increase ketone bodies.
Path is due to type 2 bodies where body cant break down glucose and cant go through glycolysis to CAC. Produce tremendous amount of ketone bodies, Drops pH of blood which leads to death.
