Lipid transport simple Flashcards Preview

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Flashcards in Lipid transport simple Deck (14)
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1
Q

outline chylomicron transport

A
  1. Lipids are loaded into chylomicrons in the small intestine and move to the lymph via lacteal in the villi and then are emptied into the blood via the thoracic duct into the left subclavian
  2. At the walls of capillaries, chylomicrons are partially metabolised by lipoprotein lipase (LPL) supplying the cells with the lipids they need
  3. Once the lipid content of the chylomicrons falls below 20% it becomes a chylomicron remnant and travels to the liver to finish being broken down
2
Q

why is LDL known as bad cholesterol

A

has a longer half life meaning it is more likely to be oxidised

3
Q

outline oxidation of an LDL

A

LDL is phagocytksed by macrophages and become foam cells –> contribute to atherosclerosis

4
Q

having low LDL

A

reduces the risk of foam cell formation and therefore atherosclerosis risk reduced

5
Q

VLDL

A

very low density lipoprotein

6
Q

IDL

A

intermediate density lipoprotein

7
Q

LDL

A

low density lipoprotein

8
Q

HDL

A

high density lipoprotein

9
Q

outline VLDL, IDL and LDL metabolism

A
  1. TAG produced/ stored in the liver is released within VLDL (containing mostly lipids and some cholesterol esters)
  2. VLDL binds to lipoprotein lipase on the outside of cells seeing lipids and depletes its TAG content –> becoming IDL
  3. IDL binds to more LPL and depletes its TAG store until it is nearly completely gone –> become LDL
  4. LDL enters hepatocytes or cells that need cholesterol
  5. LDL gets endocytose and digested by lysosomes
10
Q

how does the LDL know which hepatocyte to enter

A

hepatocytes and cells expressing receptors for the ApoB-100 ligand found on the LDL

11
Q

HDL is known as

A

good cholesterol

12
Q

why is HDL good cholesterol

A

removes excess cholesterol from peripheral tissue therefore decreasing chance of atherosclerosis

13
Q

HDL metabolism

A
  1. Empty HDL particle is released from the liver and receives excess cholesterol from body cells and Ldl
  2. It then transports this to the liver or stereogenic cells
14
Q

stereogenic cells

A

can be used to produce steroid hormones and bile salt