Zusammenfassung der Ressource
Lipids
- Types of Lipids
- Triacylglycerols
- Glycerol
fundamental unit
- Prochiral
- Three fatty acid chains
- Phospholipids
- Two fatty
acids
- Head group with
phosphate (phosphatidyl)
- Phosphatidic acid: X=H
- X=Ethanolamine:
p-tidylethanolamine
- -choline: X=choline
- -serine: X=serine
- -glycerol: X=glycerol
- X= myo-Inositol 4,5-bisphosphate--PIP2
- X=phosphatidylglycerol: Cardiolipin
- Sphingolipids
- Fatty acid
- Sphingosine
- Head group
- Ceramide: X=H
- Sphingomyelin:
X=phosphocholine
- Glycosphingolipids
- Globoside: X=simple
oligosaccharide
- Ganglioside: X=
complex
oligosaccharide
- Sterols
- Four fused carbon rings
- Primary animal tissue
component: cholesterol
- Amphipathic
- Derivative: bile acids
- Functions of lipids
- Storage of Energy
- Higher reduction potential
- No need for osmotic control
- Degraded by lipases
- Signals and cofactors
- Platelet-activating factor--ether lipid
triggering platelet aggregation
- Blood type determinants
- Eicosanoids
- Used in inflammatory responses
- Primary eicosanoid:
Arachidonate/arachidonic acid
- Prostaglandins
Anmerkungen:
- Five-carbon ring; derived from prostate gland; stimulate muscle contraction or wake-sleep cycle/responsiveness.
- Thromboxanes
Anmerkungen:
- Ether-containing six-membered ring; produced by platelets
- Leukotrienes
Anmerkungen:
- Three conjugated double-bonds; potent biological signals (e.g. too much of this causes asthma)
- Lipoxins
Anmerkungen:
- Lots of hydroxyl groups present along the chain; anti-inflammatory agents stimulated by low doses of aspirin
- Synthesis of prostaglandins and
thromboxanes catalyzed by
cyclooxygenase-2
- NSAIDs inhibit COX-2
and formation of the
connected acids
- Synthesized by
Phospholipase A2
- Hormones/message senders
Anmerkungen:
- Steroids lack the alkyl chain.
- Structural integrity
- Membranes
- Vitamins
- Vitamin E
Anmerkungen:
- Tocopherols
- Vitamin K1
Anmerkungen:
- Vitamin D
- Converted to calcitriol by liver
- Photochemically driven reaction
- Vitamin A
Anmerkungen:
- Synthesized from beta-carotene
- reduced to retinol, oxidized to
cis-retinal, one bond change
permits vision
- Enables vision
- Lipids in action
- PI response
- Hormone binding
- GTP-GDP exchange on Gqalpha
- Gqalpha moves to and activates Phospholipase C
- PIC cleaves Pip2 to IP3 and diacylglycerol
- Dag anchors Protein kinase C
- IP3 opens calcium channel
- Ca ions further activate PkC
- Cellular responses
- Naming lipids
- Delta= position of bonds
- number of carbons:number of double bonds
- e.g. 16:2
- Omega-n acids, numbered from
the last carbon
- Greek names for number of carbons
- Isoprene