ch 8 Flashcards
Why are most unsaturated fatty acids found in phospholipids in the cis rather than trans conformation?
The reason is fluidity. The cis-configuration of the double bond on unsaturated fatty acids put a rigid bend in the hydrocarbon chains which interferes with crystal packing , causing reducing van der Waals attractions between molecules. Thus, cis-double bonds maintain fluidity of fatty acids. While , such structural effect is not found in case of trans-unsaturated fatty acids.
what does saturated mean?
all carbons have hydrogens attached no double bonds present
what does unsaturated mean?
theres a double bond present
what does this mean in delta nomenclature: 16:3Δ6,8,12
16 is the number of carbons, 3 is the amount of double bonds, and the 6,8,12 is the location of the double bond
what do fatty acids start with
a carboxylic acid
what do saturated and trans unsaturated fats have in common
both are very densely packed raising the density making these fats more solid like at room temp like butter
why are cis unsaturated fats different compared to saturated and trans unsaturated fats
they have gaps in between chains of carbons causing them to be more kinked and not packed well causing them to be more fluid
cis double bonds and short chains are good for what
more fluid
longer chains and trans double bonds are good for what
tightly packed things
in cold temps, what type of fats would be good for fish to have to not freeze, why and why not
the best for cold weather would be cis double bonds with short chains because the fats will be more fluid and liquid, if fats were saturated, they would become too stiff ex. salmon
in hot temps, what type of fats would be good for fish to have to not boil, why and why not
the best for hot temps would be saturated and longer chains because cis double bonds would be too fluid and not structurally useful
what is a glycerophospholipid made up of
theres an amine group connected to the a phosphate group attached to the sugar or glycero portion that has an ester bond with the fatty acid (hydrocarbon tail)
how is a triglyceride similar to a glycerophospholipid? how are they different?
similarities: they condense with a fatty acid at c-2 and c-3 of glycerol and they have a glycerol backbone
differences: triglycerides are fatty acids and hydrophobic, phospholipids have a phosphate group, amino group and are amphiphilic
why did nature choose fats over polysaccharides as a long term storage of energy
c-h bonds have more energy when broken compared to c-o bonds. glycogen has lots of oxygen, not useful for energy
why is corn oil liquid at room temp but margarine made from hydrogenated corn oil is a soild at that temp
when you hydrogenate corn oil, you can form single bonds and or trans double bonds, we know that unsat and trans DB can be densely packed making them easier to form a solid compared to cis bonds that have gaps good for fluidity
how to NSAID reduce pain and inflammation but can also cause increased bleeding
first we need to define COX enzymes: they produce thromboxanes that create blood clots. NSAIDS are cox inhibitors which means that they can help with smooth muscle contraction causes by pain and inflammation by blocking prostaglandins that cause this but also block thromoboxanes that create blood clots
how is a glycerophopholipid similar to a glyceroglycolipid and how are they different
similarites: both have 2 fatty acids chains, and 2 glycero backbones
differences: glycerophospholipid has a amino alcohol and phophate group (-) while glyceroglycolipids have a galactose sugar as head
amino alcohols are common polar heads in phospholipids, what are they
ethanolanime (+), choline(+), serine(overall neutral)
how is a glycerophospholipid similar to a sphingophospholipid , how are they different
similarities: both have phosphate and choline at C1 and both have a fatty acid condensed at c2
differences: glycero has an ester linkage and has fatty acid links at c-3,, sphingo has an amide linkage to fatty acid, part of sphingosine (trans double bond) and has a free oh at c-3
sphingomyelin distinguish
its overall neutral, has a phosphate group, an amino alcohol as polar head
cerebroside
sugar as polar head, has 1 sugar and is neutral
globosides
sugar as polar head, 2 or more sugars and is neutral
gangliosides
sugar as polar head, has several sugars, sialic acid and has a negative charge
how do these sphingolipids help to strengthen the myelin sheath
they increase density by having sat hydrocarbons chain with trans DB of sphingosine
how is GalCer linked to MS
the Galactose is a marker for immune system to attack, autoimmune disease
how does the protein manufactured from the information in that gene determine blood type
through DNA transcription and translation, you have a protein that becomes an enzyme called glycosyltransferase (transfers sugars on blood) so that we have ABO blood types
what is glycosyltransferase
enzyme that transfers sugars onto blood
type A blood has what sugars
GTA (NAG sugar)
type B blood has what sugars
GTB (Gal sugar)
type O blood has what sugars
NO GT no transfer
name two disease associated with defects in recycling sphingolipids
Tay Sachs, Fabry, and Gauchers
how can you tell if a molecule is cholesterol
has four rings connected to each other
cholesterol is what
steroid
what are bile salts and where do they come from
they are made in the liver from cholestrol to emulsify fats and excrete the fats
whats HDL and LDL
HDL good cholesterol, LDL bad cholesterol part of storage
lipoprotein are what layer
mono layer
plasma membranes are what layer
bilayer
how is the surface of a lipoprotein different from plasma membranes
lipoproteins are hydrophobic while plasma membrane has portions that are hydrophobic or hydrophilic
what type of lipid is vitamin A
terpenes made of many isoprenes
while both glucagon and cortisol increase glucose conc, what are the differences between these
glucagon activated GP to break down glycogen into glucose while cortisol represses the transcription of a gene that ultimately stops the production of an enzyme
cortisol does what and where is it made
made in adrenal glands and regulates glucose levels
progesterone does what
prepares uterus for implantation of fetus
androstenedione does what
male hormone, hair, deep voice
where does cortisol, progesterone, and androstenedione come from
cholesterol
what sphingolipid disappears in demyelinating disorders
sphingosine
what sphingolipid surrounds and insulates axons in neurons with high density sheath
sphingomyelin
what sphingolipid determines the ABO blood types
ganglioside
decrease the percentage of cholesterol in the membrane of cold water fish causes what
more fluid
lipid rafts are more rigid than the rest of the membrane. what causes the rigidity of this structure.
cholesterol tightly packed with phospholipids
why is the surface of lipoprotein a monolayer
polar heads outside and fatty tails face hydrophobic core
