Triacylglycerides and Phospholipids

Question 1

Phosphatidic acid

Answer 1

Complex lipid

1st chain is phosphoryl group

Other two chains are carbon chains

Question 2

L glycerol 3 phosphate role

Answer 2

Precursor to phosphatidic acid
True for both pathways

Question 3

L glycerol 3 phosphate structure details

Answer 3

No double bond
Alcohol in middle and top

In the name

Question 4

Why is phosphatidic acid important?

Answer 4

Precursor to glycerolipids and phospholipids

Question 5

Why are glycerolipids and phospholipids important?

Answer 5

Membrane lipids = regulate curvature
Sphingolipids = self vs non self
Glycerolipids = major energy storage

Question 6

Triacylglycerol structure reminder

Answer 6

Glycerol backbone
3 fatty acid chains

No phosphate group!!!

Question 7

Glycerophospholipid structure

Answer 7

Same as phosphatidic acid but on O of PO4 group
Head group attached

Question 8

What is the precursor to glycerolipids and phospholipids?

Answer 8

Glycerol 3 phosphate
Backbone precursor
Alcohol makes ya fat

Phosphatidic acid
Long chains precursor and phosphorous for lipid precursor
Fussy acid = bubble of fat for protection

Question 9

Glyceroneogenesis

Answer 9

What PEPCK catalyzes in adipose tissue
Pyruvate to glycerol 3 phosphate

Adipose tissue slack glycerol kinase

Question 10

Adipose tissue lacks what enzyme?

Answer 10

Glycerol kinase

Needs to use glyceroneogenesis

Question 11

Glucocorticoids

Answer 11

Glue = sticking together two different effects

Limits PEPCK in adipose = more free FA
Promotes PEPCK in liver = more triglycerol production

Question 12

Thiazolidinediones

Answer 12

Tea = healing = diabetes treatment
Activates PEPCK in adipose
=more free FA

Question 13

Rosiglitazone

Answer 13

Sig nasty man = heart attack

3 aromatic rings
1 at end is symmetrical looks like a fat man raising hands ONO with S = NS= nasty man

Question 14

Cortisol

Answer 14

Glucocorticoid

Cort = cort

Question 15

Precursor to phospholipid synthesis

Answer 15

Phosphatatidic acid (from glucose or Triacyl glycerol)

P—> 1,2 diacylglycerol

Question 16

Glycerophospholipids: 2 pathways for head group addition - reminders

Answer 16

CDP = cytidine diphosphate = important for both

1st = more common = only one used by bacteria
= CDP activates diacylglycerol = CDP-diacylglycerol
Oh of alcohol head group is nucleophile that attacks phosphorous
Releases CMP

2nd =
Phosphoric acid is activated by CDP
Acts as nucleophilic attack accepter
Oh of diacylglycerol attacks

Question 17

CDP structure

Answer 17

Cytidine + 2x Phosphorous groups

Question 18

Serine structure reminder

Answer 18

3cs
Alcohol
Serine in middle
=serene = alcohol = n in middle j chilling

Carboxylase on other side of oh

Question 19

EthanolAmine structure reminder

Answer 19

Amine that is also an alcohol
2Cs

Question 20

Choline structure reminder

Answer 20

Choline = chlorine = n swimming in methyl

Question 21

General pathway of intermediates for phosphatidyl choline

Answer 21

CDP-diacylglycerol

Phosphatidyl ethanolamine

Phosphatidyl choline

Question 22

How does phosphatidyl serine synthesis differ between species?

Answer 22

Yeast/ bacteria =
1st pathway of group addition
CDP diacylglycerol reacts with serine to release CMP

Eukaryotes=
Head group exchange reaction with either phosphatidyl choline or phosphatidyl ethanolamine
Generates freee choline or free ethanolamine

Question 23

How does phosphatidyl choline synthesis differ between species?

Answer 23

Bacteria/ yeast=
Starts with CDP-diacylglycerol
To phosphatidyl serine
To phosphatidyl ethanolamine
To phosphatidyl choline

Mammals=
Choline + choline kinase —> phosphocholine
Needs atp

Reacts w CDP —> CDP choline
Releases PPi

Reacts with diacylglycerol
Releases CMP

Phosphatidyl choline

Question 24

General reaction for phosphatidyl choline in mammals

Answer 24

Choline +1 ATP + 1CTP + 1 diacylglycerol
—> CMP + PPi + ADP + phosphatidyl choline

Question 25

Pathway of phosphotidyl choline from phosphatidic acid

Answer 25

ATP need is unknown….. Phosphatidic acid —> 12 diacylglycerol —> phosphatidyl serine —> phosphatidyl ethanolamine —> phosphatidyl choline Or Phosphatidic acid —> 12 diacylglycerol —> added to CDP choline —> phosphotidylcholine

Question 26

Major cofactors of phospholipid synthesis

Answer 26

CDP SAM

Question 27

PSS1 definition and function

Answer 27

Phosphotidyl serine synthase I Transfers both phosphotidyl chlorine and phosphotidyl ethanolamine to phosphotidyl serine in mammals

Question 28

PSS2 definition and function

Answer 28

Transforms phosphotidyl ethanolamine into phosphotidyl serine in mammals

Question 29

PS decarboxylase definition and function

Answer 29

Phosphatidyl serine carboxylase Converts phosphatidyl serine to phosphatidyl ethanolamine

Question 30

Methyl transferase

Answer 30

Transfers methyl group from SAM (adoMet) to phosphotidyl ethanolamine To form Phosphotidyl choline X3 CH3 is on sulfur group

Question 31

Choline kinase

Answer 31

ATP activated Phosphorylation of fee choline to form phosphocholine

Question 32

Why would a rat with a methionine deficiency be able to thrive when diet is high in choline?

Answer 32

Phosphatidic acid is important for lots of functions 2 pathways for creation De novo requires SAM which is a methionine Salvage pathway requires free choline and no methionine

Question 33

Triacylglycerols

Answer 33

Storage lipids Glycerol backbone 3 FAs

Question 34

Glycerophospholipids

Answer 34

Membrane Glycerol backbone 2 FAs 1 phosphate group + alcohol

Question 35

Glycolipid

Answer 35

Membrane Sphingosine backbone FA Saccharide

Question 36

Sphingolipids

Answer 36

Either phospholipid or glycolipid If phospholipid = Sphinegosine backbone Fa Po4- choline

Question 37

Glycerophospholipid vs triglyceride formation pathway

Answer 37

Both= DHAP(NADH) or glycerol (atp)—> l glycerol 3 phosphate —> phosphatidic acid = 2ATP due to Acyl CoA synthetase Glycerophospholipid= phosphatidic acid —> 12 diacylglycerol —> Glycerophospholipid Triacyl glyceride = phosphatidic acid —> 12 diacylglycerol —> triacylglyceride Needs 1ATP acyl coa synthetase So Glycerophospholipid = 3 atp Triacylglyceride = 4atp