Hyperlipidaemia And Atherosclerosis Flashcards
What are lipids?
Umbrella term grow a diverse range of compounds that are soluble in organic solvents and largely insoluble in water
Some are essential for health
Some contribute to disease
Major lipids and their subdivision
Sterols - cholesterol, phytosterols
Related to FAs- fatty acids, triglycerides, phospholipids
Eicosanoids
Vitamins ADEK
Sphingolipids
What is the function of cholesterol
Structural component of membranes
Precursor for bile acid and steroid synthesis
Function of fatty acids and triglycerides
Energy source
Phospholipids are..
A structural component of membranes
Function of eicosanoids
Multiple, including effects on blood coagulation, bronchial and vascular contractility, reproduction
Function of sphinogolipids
CNS; blood group substances
Describe the functions of fat soluble vitamins
A - vision
D - calcium homeostasis and maintenance of bone integrity; various other functions eg immunomaturation
E - Neural function; antioxidant
K - activation f gloating factors
Describe the structure of lipoproteins
Hyrophobic cord made of triglycerides and cholesterol esters
Amphipathic phospholipid shell and free cholesterol
Amphipathic protein = apolipoprotein
What pathways describes what happens to ingested fats
Exogenous lipid pathway
What is the fate of LDL
Taken to liver via - LDL receptors (interacts with B100) -or a related protein
Taken up by peripheral cells for utilisation
Taken up by arterial wall macrophages -> oxidised -> foam cells = atherosclerosis
…… is the cause of most vascular disease
Atherosclerosis
Eg. Stroke, MI, peripheral vascular disease, aneurysms
Risk factors for atherosclerosis
Hyperlipidaemia (especially high LDL and low HDL) is a major risk factor
As well as hypertension, smoking, diabetes etc
Fatty acids must get into the…
Mitochondria
Describe the pathway from blood - mitochondrial matrix
FA carried by albumin -> cytoplasm of outer mitochondria memb -> inner mitomembrane-> mitochondrial matrix
Describe beta oxidation of fatty acids
4 reactions
Acetyl-CoA -> (oxaloacetate) -> kreb’s cycle
Reducing equivalents (NADH+FADH2) -> Electron transport cycle
Fatty acyl-CoA (shorter by 2 carbons)
Acetyl-CoA not utilised in Kreb’s cycle converted into …. In the ….
Ketone bodies in the liver
Acetoacetate; 3-hydroxybutyrate; (acetone)
Uses of ketone body
Important source of energy
Particularly useful for the brain
Where does fatty acid biosynthesis occur and what does it allow
• Occurs in the cytoplasm
• Allows
– Nutrients to be stored as triglyceride
– Fatty acid formation for cell membranes and other roles
• In situations with excess citrate, Acetyl CoA is metabolised to Malonyl CoA
• This is then extended by 2 Carbon chains in a series of reactions catalysed by the fatty acid synthase complex
