Lipids III Flashcards Preview

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Flashcards in Lipids III Deck (41)
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1
Q

what is different about membrane lipiids

A

they carry electral charges

2
Q

what is the rate limiting step of the synthesis of PC

A

rphosphocholine transferred to CTP by phosphocholine cytidyltransferase

3
Q

how is PE syntheised

A

ethanolamine activated, transferred to CTP

transfer ethanolamine to diacylglyceral

4
Q

what is PS made by

A

phosphatidyl serine synthase - changes polar head froup on PE with serine

5
Q

what is unique about the synthesis of PI

A

the dicylglycerol (not the head group) is activated by binding to CTP.

6
Q

cardiolipin

A

biologically important lipid of inner mitochondrial membrane

7
Q

structure of cardiolipin

A

phospholipid dimer where 2 phosphatidic acid molecules are connected bia glycerol bridge

8
Q

function of cardiolipin

A

helps with foldign of mitochondrial electron transport compoexes,
buffers electrons in membranes

9
Q

when do you see cardiolipin insufficiency

A

normal ageing but also alzheimers and parkinsons

10
Q

outer leaflet contains waht

A

choline containing lipids PC and sphingomylen

11
Q

inner leaflet contains waht

A

PE and negatively charged lipid like PS

12
Q

how is arachidonic acid introduced into phospholipids

A

exchange of FAs bia phospholipases

13
Q

characteristics of freashly synthesized phospholipds

A

saturated FA or oleic acid in C1

unsaturated FA in C2

14
Q

phospholipise C reaction

A

phospholipase C —> IP3 + DAG

15
Q

unpon stimulation what does phospholipiase A2 do

A

cleave arachidonic acid from the C2 of phospholipids

16
Q

general function of phospholipiase A2

A

prodcues signalling molcules of prostaglandin and thromboxane classes.

17
Q

what does arachidonic acid need to be synthesized from

A

linoleic acid (essential FA)

18
Q

how is free arachidonic acid converted into PGH2

A

substrate for CO/PGH synthase complex

19
Q

PGH2

A

precursor for wide viarety of signaling lipids

20
Q

functions of PGs

A

vasoluation during inflammation
stimulate contractiosn of uterus
inhibit platelet aggrestion

21
Q

where can prostaglandin synthesis be inhibited

A

level of phospholipiase A2 by corticosteroids

levle of COX1/2 and prostagland synthsie by NSAIDS

22
Q

leukotrienes

A

family of bioactive liipds that function as messengers and hormones

23
Q

how are leukotriens synthesized

A

from arachidonic acid follwoign stimulation of phospholipiase A

24
Q

what is leukotriene syntheiss initated by

A

lipoxygenase reaction

25
Q

what is the half life of keukotrines

A

4 hours

26
Q

function of LTC4 and LTD4

A

smooth muscle contraction

27
Q

how can you treat asthma

A

lipoxygenase inhibitors which slow production of leukotrines

28
Q

plasmalogens

A

special category of membrane lipids that contain fatty alcohol in ether linkage

29
Q

what parts of the body are rich in plasmalogens

A

immune system

brain heart

30
Q

what is plasmalogen deficieny assocaited with

A

alzheimers and down syndrome

31
Q

what is the critical step of plasmalogen syntehsis

A

induction of ether linkage

32
Q

where does the critical step of plasmoglen synthesis take place

A

peroxiaomes

33
Q

what do patients with zellweger have

A

plasmalogen defiency

34
Q

what are sphingolipids derived from

A

teh alcholo spingosine

35
Q

do sphingolipids contain glyceral

A

no

36
Q

what is the lipid component of spingomyelin

A

ceramide

37
Q

transfer of phosphocholine to ceramide leads to

A

spingomylein

38
Q

transfer of glucose or galactose on cereamide leads to

A

cerbrosides

39
Q

transfer of sulfate group to cerebrosides yeilds

A

sulfatide

40
Q

transfer of 2-4 neutral sugars to ceramid lead to

A

globosides

41
Q

transfer of several sugars to ceramide

A

gangliosides