Chapter 8- Lipids Flashcards
Common property amongst lipids
mostly hydrophobic
Lipids are soluble in _____
organic solvents (ex. chloroform and methanol)
Types of storage lipids
- Fatty Acids
- Triacylglycerols
Types of structural lipids
- Glycerophospholipids
- Sphingolipids
Types of structural and functional lipids
Steroids/ sterols
fatty acid composition:
- Carboxylic chain
- Long aliphatic chain
Why are fatty acids slightly water soluble?
COOH group
Which carbon is Carbon 1 on fatty acids?
Carboxyl carbon
Fatty acids are rarely found _____ and are usually found as _____
alone
part of other lipid molecules
Saturated= ____
Unsaturated= ______
NO double bonds
Double bonds
Monounsaturated means:
Polyunsaturated means:
Only 1 double bond
more than 1 double bond
Double bonds in lipids are almost always____
Cis
When naming saturated fatty acids in triacylglycerols and glycerophospholipids, the suffix ____ is added to the name
-oyl (ex. Steric acid –> Steroyl)
When naming unsaturated fatty acids in triacylglycerols and glycerophospholipids, the suffix ____ is added to the name
-oleoyl (ex. Linoleic acid —> Linoleoyl)
What determines the Tm of a fatty acid?
chain length
degree of unsaturation
Saturated fatty acids have a ____ Tm because___
high
they can pack very tightly due to no double bond bends and kinks, which increases intermolecular forces
Unsaturated fatty acids have a ____ Tm, because ____
low
the force kinks caused by DB’s cause a reduction in intermolecular forces
The more double bonds in a fatty acid, the _____ the melting temp
Lower
The longer the carbon chain in a fatty acid, the _____ the Tm
higher
What is hydrogenation
converting cis DB into single bonds which results in a higher Tm
What is partial hydrogenation?
converting cis DB to trans-DB
The simplest lipids constructed from fatty acids are ____
Triacylglycerols
Triacylglycerols are made of
3 fatty acids in ester linkage with a single glycerol
Triacylglycerol is ______ and water- ______
nonpolar
insoluble
Simple triacylglycerols contain
one type of fatty acid
Mixed triacylglycerols contain
two or three different fatty acids
Adipocytes (fat cells) are specialized for ____
synthesis and storage of triacylglycerols
Advantages of triacylglycerols vs sugars
- more reduced than carbs (release more E)
- Hydrophobic (less weight to carry)
The longer the hydrocarbon chain =
the more acetyl-coA it can store
Membrane lipids are ____
amphipathic
- hydrophobic interactions with each other
- hydrophilic interaction w water
3 classes of structural lipids
- glycerophospholipids
- sphingolipids
- sterols
____ are the major lipid components of biological membranes
Glycerophospholipids
glycerophospholipids consist of :
- glycerol-3-phosphate
- fatty acids at C1 and C2 linked by esters
- Polar group joined to glycerol through a phosphodiester bond
2 parts of glycerophospholipids:
- polar head group
- lipid tail
glycerophospholipids are described by their _____ group
head
glycerophospholipids are named by __
naming the chains and the head group
Sphingolipids contain _____ but no ____
polar head + two hydrophobic tails
glycerol
Basic building unit of terpenes
isoprene
steroids and sterols are _____ derivatives
isoprene
Sterols share the ________ and it is _____
sterol nucleus
rigid and almost planar
most abundant steroid in animals
cholesterol
cholesterol is weakly _____ due to the ______ on C-3
amphipathic
polar OH
