CHAPTER 8 Lipids and Proteins Flashcards
(53 cards)
what are lipids
Lipids are defined based on solubility. They are insoluble in water but soluble in aprotic organic solvents like acetone, chloroform, diethhyl ether, methylene chloride
what do you mean by lipids being amphipathic
They are amphiphatic meaning the molecules has two ends, one polar(water soluble) and non polar9not solubrle in water)
Give examples of open chain compounds
Fatty acids, triacylglycerols, sphingolipids, glycolipids
Give examples of fused ring compounds
cholesterol, steriod hormones, bile acids
How can you tell that a lipid is saturated and unsaturated
It is saturated when the molecule only have sungle bond carbons and if they have double bonds they are unsaturated. They need more space w themm (liquid) unlike sa single bond na they can be solid
true or false: unsaturated fatty acids have lower boiling points than saturated. why?
Kasi tightly packed ang saturated bonds so need nila ng more energy or boiling point para maseparate unline sa unsaturated na nagfform ng kink kaya medyo loose sila di nila need masyado ng boiling shit to separate.
lipids formed by esterifying three fatty acids to a glycerol molecule.
triacylglycerols
Explain the two proces of esterifying triacylglycerols
1 is through lipase forming ionized fatty acid and one is through NaOH or KOH forming sodium salt of fatty acid
What hydrolizes lipids forming triacylglyceride into glycerols
lipase
phosphoacylglycerols are also classfied as
phosphatidyl esters
how can you say that a phosphatidic acid is tripotic in nature
One molecule can form ester bonds to glycerol and some other alcohol
to create phosphatidyl esters.
Complex mixtures of esters of long-chain carboxylic acids and long-chain
alcohols.
* Serve as protective coatings for plants and animals.
waxes
Complex mixtures of esters of long-chain carboxylic acids and long-chain
alcohols.
* Serve as protective coatings for plants and animals.
Waxes
parent compounds for glycolipids.
ceramide
occurs in cell membranes.
▪ Highly hydrophobic
▪ Acts as a precursor of other steroids
▪ Plays a role in the development of atherosclerosis
cholesterol (steroid)
what noncovalent interaction holds the lipid bilayer
Van der Waals and hydrophobic interactions
Phospholipid bilayer is composed of
surface= polar
interior- nonpolar saturated and unsaturated chains of fatty acids and the fused ring of cholesterol
major force driving the formation of lipid bilayers.
Hydrophobic Interaction
sin the context of membrane fluidity, describe saturated and unsaturated acids
in nsaturated, its more rigid for the straight chains carbon leads to rigidity and in unsaturated, the kink causes disorder in its packing and leads to greater fluidity
how does cholesterol influence rigidity
can enhance order and rigidity.
o The fused-ring structure of cholesterol is rigid.
o Stabilizes extended straight-chain arrangement of saturated fatty
acids by van der Waals interactions.
TRUEN or FAlse: Plant Membranes – have a lower percentage of unsaturated fatty acids
than animal membranes.
FALSE: HIGHER
explain relationship of lipid and temperature
at higher temperatures, lipid move freely and less rigid and in lower temperatures, the lipid is more rigid
what are the types of membrane proteins
differentiate
Peripheral Proteins – loosely bound to the outside of a membrane.
o Bound by polar interactions, electrostatic interactions, or both.
o Can be removed by raising the ionic strength of the medium.
o Example: heterotrimeric G protein
- Integral Proteins – embedded in a membrane.
o Can be removed by treatment with detergents or extensive sonication.
▪ May lead to the denaturation of the protein.
o Example: rhodopsin
anchoring motifs in proteins to membranes
N-myristoyl and S-palmitoyl:
