Lipid transport Flashcards Preview

Phase 1 - S2 Metabolism, Endocrinology, Haematology > Lipid transport > Flashcards

Flashcards in Lipid transport Deck (54)
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1

what are the 5 lipoprotein transporters

chylomicrons
VLDL
IDL
LDL
HDL

2

true or false: lipids are hydrophilic

false - they're hydrophobic which makes them difficult to transport in the blood

3

how are fatty acids transported in the blood

by being carried by albumin

4

how are 98% of lipids transported

in lipoprotein particles

5

describe phospholipid molecules

- they have a hydrophobic tail made up of 2 fatty acids
- glycerol backbone
- phosphate
- polar hydrophilic head attached to the phosphate

6

what part of the phospholipid classifies it

the hydrophilic head which can be either choline or inositol

7

what shape of phospholipids carry aqueous cargo

liposome

8

what shape of phospholipids carry hydrophobic cargo

micelle

9

where is most of the bodys cholesterol obtained

from synthesis in the liver
(small amount comes from the diet)

10

what is cholesterol used for

- for stability in membranes
- precursor to steroid hormones
- precursor to bile acids

11

give 4 examples of steroid hormones

oestrogen
testosterone
aldosterone
cortisol

12

how is cholesterol transported around the body

it is converted into cholesterol esters but LCAT enzymes

13

what are apolipoproteins

proteins found either passing through the phospholipid membrane (peripheral) or on the surface (integral) of lipoproteins

14

what are the functions of apolipoproteins

- allows lipoprotein molecule to form by allowing packaging of the water insoluble contents
- act as cofactors for enzymes to break down lipids
- act as ligands to receptors to take up cargo

15

what does the density of lipoproteins depend on

the amount of apolipoproteins on their surface

16

in a flotation ultracentrifugation which lipoprotein migrates the furthest

HDL

17

for more dense lipoproteins what happens to the size of their diameter

It decreases

18

what apolipoprotein is added to chylomicrons before they enter the lymphatic system

apoB-48

19

when chylomicrons enter the left subclavian vein what other apoproteins are added

apoC and apoE

20

what does the addition of apoC to chylomicrons allow

the binding to lipoprotein lipase on adipocytes and muscle allowing the chylomicrons to release their fat

21

what do chylomicrons mostly contain

dietary fat

22

what do VLDL contain

TAGs synthesised by the liver

23

what happens to chylomicrons when the TAG content is reduced to 20%

the apoC dissociates and the chylomicron becomes a chylomicron remnant

24

what happens to chylomicron remnants

they return to the liver and the apoE allows it to bind to LDL receptors on hepatocytes to be taken up by receptor mediated endocytosis

25

where is VLDL synthesised

in the liver

26

what apoproteins bind to VLDL

apoB100, apoC and apoE

27

how do VLDL become depleted

they bind to LPL in the muscle and adipose cells

28

what happens to the fatty acids taken up by muscle and adipose cells

muscle - used in energy production
adipose - resynthesised to TAGs and stored

29

how are IDLs formed

when the TAG content of VLDL drops to 30%

30

how are LDL formed

when the TAG content of IDL depletes to 10% and so loses its apoC and apoE