LIPIDS Flashcards
week 3 lect 2 Ioannis
biological lipid?
generally insoluble in water but soluble in organic solvents, they’re hydrophobic
Biological functions of lipids?
storage of energy
insulation from environment
protection of organs
water repellent
buoyancy control and acoustics in marine mammals
membrane structure
cofactors for enzymes
signalling molecules
pigments
antioxidants
inflammation
digestion
when a fatty acid is not a component, what is it referred to as?
a free fatty acid (FFA) or an un-esterified fatty acid
what is the fatty part of a fatty acid?
the hydrocarbon chain (H and C atoms) - it is the hydrophobic portion
what is the acid part of a fatty acid?
the carboxyl group - it is the hydrophilic portion
What are monounsaturated fatty acids?
have a single double bond between two carbons in the chain - usually results in a kink
What are polyunsaturated fatty acids?
have multiple double bonds between different carbons
the more double bonds in an unsaturated fatty acid?
the more fluid the fatty acid and the lower the melting point
MUFA?
monounsaturated fatty acids
PUFA?
polyunsaturated fatty acid
Why do reindeer’s have a high proportion of PUFA’s in the cell membranes of a reindeer’s leg near the hoof?
always in contact with cold snow - always cold and we need to maintain the fluidity of the membrane
Multiples PUFA’s - not stacked due to the kinks, so it is not tightly packed, if too rigid there are issues with ion channels and transport over the membranes
alpha carbon?
carbon number 2 on a fatty acid
what are omega-3 FAs considered as?
anti-inflammatory
what are omega-6 FAs considered as?
pro-inflammmatory (arachidonic acid)
Name three arachidonic acid derivatives?
Prostaglandins, Thromboxanes, Leukotrienes
What does NSAIDs block?
inflammation pain and fever (bad stuff)
BUT ALSO
mucosal protection, renal blood flow and haemostasis (GOOD STUFF)
Triacylglycerols (triglcerides / TAGS)
thre fatty acids linked to a glycerol
ester bonds can be hydrolysed by?
enzymes called lipases or esterases –> secreted by pancreas
where does the ester bond form in a triglyceride?
between the three OH groups in glycerol forms an ester bond with the carboxyl group of a fatty acid
FAs are converted into TGAs within the cell and exported in the blood as part of the?
Lipoprotein pathway (and/or chylomicrons)
why does cholesterol go in and out of the liver again and again?
so it can be re-packaged and can be sent to the tissues that need it
where are triglycerides stored?
in the ‘fat tissue’
(adipose tissue formed of adipocytes)
Lipogenesis?
synthesis of fatty acids/TAG