Triacylglycerides and Phospholipids Flashcards
Phosphatidic acid
Complex lipid
1st chain is phosphoryl group
Other two chains are carbon chains
L glycerol 3 phosphate role
Precursor to phosphatidic acid
True for both pathways
L glycerol 3 phosphate structure details
No double bond
Alcohol in middle and top
In the name
Why is phosphatidic acid important?
Precursor to glycerolipids and phospholipids
Why are glycerolipids and phospholipids important?
Membrane lipids = regulate curvature
Sphingolipids = self vs non self
Glycerolipids = major energy storage
Triacylglycerol structure reminder
Glycerol backbone
3 fatty acid chains
No phosphate group!!!
Glycerophospholipid structure
Same as phosphatidic acid but on O of PO4 group
Head group attached
What is the precursor to glycerolipids and phospholipids?
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
Glyceroneogenesis
What PEPCK catalyzes in adipose tissue
Pyruvate to glycerol 3 phosphate
Adipose tissue slack glycerol kinase
Adipose tissue lacks what enzyme?
Glycerol kinase
Needs to use glyceroneogenesis
Glucocorticoids
Glue = sticking together two different effects
Limits PEPCK in adipose = more free FA
Promotes PEPCK in liver = more triglycerol production
Thiazolidinediones
Tea = healing = diabetes treatment
Activates PEPCK in adipose
=more free FA
Rosiglitazone
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
Cortisol
Glucocorticoid
Cort = cort
Precursor to phospholipid synthesis
Phosphatatidic acid (from glucose or Triacyl glycerol)
P—> 1,2 diacylglycerol
Glycerophospholipids: 2 pathways for head group addition - reminders
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
CDP structure
Cytidine + 2x Phosphorous groups
Serine structure reminder
3cs
Alcohol
Serine in middle
=serene = alcohol = n in middle j chilling
Carboxylase on other side of oh
EthanolAmine structure reminder
Amine that is also an alcohol
2Cs
Choline structure reminder
Choline = chlorine = n swimming in methyl
General pathway of intermediates for phosphatidyl choline
CDP-diacylglycerol
Phosphatidyl ethanolamine
Phosphatidyl choline
How does phosphatidyl serine synthesis differ between species?
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
How does phosphatidyl choline synthesis differ between species?
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
General reaction for phosphatidyl choline in mammals
Choline +1 ATP + 1CTP + 1 diacylglycerol
—> CMP + PPi + ADP + phosphatidyl choline
Pathway of phosphotidyl choline from phosphatidic acid
ATP need is unknown…..
Phosphatidic acid —> 12 diacylglycerol —> phosphatidyl serine
—> phosphatidyl ethanolamine —> phosphatidyl choline
Or
Phosphatidic acid —> 12 diacylglycerol —> added to CDP choline —> phosphotidylcholine
Major cofactors of phospholipid synthesis
CDP
SAM
PSS1 definition and function
Phosphotidyl serine synthase I
Transfers both phosphotidyl chlorine and phosphotidyl ethanolamine to phosphotidyl serine in mammals
PSS2 definition and function
Transforms phosphotidyl ethanolamine into phosphotidyl serine in mammals
PS decarboxylase definition and function
Phosphatidyl serine carboxylase
Converts phosphatidyl serine to phosphatidyl ethanolamine
Methyl transferase
Transfers methyl group from SAM (adoMet) to phosphotidyl ethanolamine
To form
Phosphotidyl choline
X3
CH3 is on sulfur group
Choline kinase
ATP activated
Phosphorylation of fee choline to form phosphocholine
Why would a rat with a methionine deficiency be able to thrive when diet is high in choline?
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
Triacylglycerols
Storage lipids
Glycerol backbone
3 FAs
Glycerophospholipids
Membrane
Glycerol backbone
2 FAs
1 phosphate group + alcohol
Glycolipid
Membrane
Sphingosine backbone
FA
Saccharide
Sphingolipids
Either phospholipid or glycolipid
If phospholipid
= Sphinegosine backbone
Fa
Po4- choline
Glycerophospholipid vs triglyceride formation pathway
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
