Hyperlipidaemia And Atherosclerosis

Question 1

What are lipids?

Answer 1

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

Question 2

Major lipids and their subdivision

Answer 2

Sterols - cholesterol, phytosterols
Related to FAs- fatty acids, triglycerides, phospholipids
Eicosanoids
Vitamins ADEK
Sphingolipids

Question 3

What is the function of cholesterol

Answer 3

Structural component of membranes
Precursor for bile acid and steroid synthesis

Question 4

Function of fatty acids and triglycerides

Answer 4

Energy source

Question 5

Phospholipids are..

Answer 5

A structural component of membranes

Question 6

Function of eicosanoids

Answer 6

Multiple, including effects on blood coagulation, bronchial and vascular contractility, reproduction

Question 7

Function of sphinogolipids

Answer 7

CNS; blood group substances

Question 8

Describe the functions of fat soluble vitamins

Answer 8

A - vision
D - calcium homeostasis and maintenance of bone integrity; various other functions eg immunomaturation
E - Neural function; antioxidant
K - activation f gloating factors

Question 9

Describe the structure of lipoproteins

Answer 9

Hyrophobic cord made of triglycerides and cholesterol esters
Amphipathic phospholipid shell and free cholesterol
Amphipathic protein = apolipoprotein

Question 10

What pathways describes what happens to ingested fats

Answer 10

Exogenous lipid pathway

Question 11

What is the fate of LDL

Answer 11

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

Question 12

…… is the cause of most vascular disease

Answer 12

Atherosclerosis
Eg. Stroke, MI, peripheral vascular disease, aneurysms

Question 13

Risk factors for atherosclerosis

Answer 13

Hyperlipidaemia (especially high LDL and low HDL) is a major risk factor
As well as hypertension, smoking, diabetes etc

Question 14

Fatty acids must get into the…

Answer 14

Mitochondria

Question 15

Describe the pathway from blood - mitochondrial matrix

Answer 15

FA carried by albumin -> cytoplasm of outer mitochondria memb -> inner mitomembrane-> mitochondrial matrix

Question 16

Describe beta oxidation of fatty acids

Answer 16

4 reactions
Acetyl-CoA -> (oxaloacetate) -> kreb’s cycle
Reducing equivalents (NADH+FADH2) -> Electron transport cycle
Fatty acyl-CoA (shorter by 2 carbons)

Question 17

Acetyl-CoA not utilised in Kreb’s cycle converted into …. In the ….

Answer 17

Ketone bodies in the liver
Acetoacetate; 3-hydroxybutyrate; (acetone)

Question 18

Uses of ketone body

Answer 18

Important source of energy
Particularly useful for the brain

Question 19

Where does fatty acid biosynthesis occur and what does it allow

Answer 19

• 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