lipids-2 Flashcards
what kind of enzymes are phospholipases
hydrolases
what do type-A phospholipases do +(what cleave and what is left)
cleaves acyl groups yielding fatty acid + alcohol
where does phospholipase A1 cleave
C-1 (cleaves between ether and carbonyl near R1)
where does phospholipase A2 cleave
C-2 (cleaves between ether and carbonyl near R2)
where does phospholipase C cleave
between glycerol and phosphate (phosphate group at C3)
where does phospholipase D cleave
between phosphate and polar head group (phosphate group at C3)
what do you get when you cleave a phospholipid with phospholipase C
diacylglycerol + phosphate head group structure
what do you get when you cleave a phospholipid with phospholipase D
phosphatidate + polar head group
what do you get when you cleave a phospholipid with phospholipase A2
R2 fatty acid and a lysophospholipid
does R1 or R2 have a more saturated carbon chain in glycerophospholipids
R1
does R1 or R2 have a more unsaturated carbon chain in glycerophospholipids
R2
is R1 usually more saturated or unsaturated in glycerophospholipids
saturated
is R2 usually more saturated or unsaturated in glycerophospholipids
unsaturated
what do you get when you cleave a phospholipid with phospholipase A1
R1 fatty acid and a lysophospholipid
which phospholipase would yield an unsaturated phospholipid from the membrane
phospholipase A2
which phospholipase would yield a saturated phospholipid from the membrane
phospholipase A1
what is the backbone in spingolipids
sphingosine
what is a sphingosine backbone (where does it come from)
non-glyceride synthesized from a serine and palmitate
is there a phosphate in the intrinsic sphingosine backbone
no
what is a ceramide (What composes it)
sphingosine attached to a fatty via an amide bond
how is the sphingosine attached to the fatty ac id
an amide bond
what determines the class of sphingolipid
the polar head group
what is the fatty acid residue like in ceramides
usually saturated
what head group does sphingomyelin share with another glycerophospholipid
Phosphatidylcholine
is sphingosine polar or non polar
it contains both a polar and non polar region
what does the polar region of sphingosine resemble
glycerol but includes an amino group
where is the variable polar group attached to in sphingolipids
C1
what is the variable polar group in sphingomyelin
phosphocoline or phosohoethanolamine
what is the variable polar group in cerebrosides
monosaccharide (glucose or galactose)
what is the variable polar group in globosides
neutral olligosaccharide structure (2 or more sugars)
what is the variable polar group in gangliosides + charge
oligosaccharides including at least one sialic acid (-)
which versions of sphingolipids are glycolipids
cerebrosides, globosides, gangliosides
does sphingocine have an instrinsic charge
no
does gangliosides have an net charge
yes -
does globosides have an net charge
no
how is the neutral monosaccharide attached to the sphingosine
glycosidic bond
what kind of charge is associated to sialic acid residues
-1
where are galactolipids/ sulfolipids commonly found
in plant cells “chloroplast inner membrane)
what is special about galactolipids/ sulfolipids
they do not require phosphate
what can the charge be on sulfonates
they may carry a negative charge
are all glycolipids galactolipids
no
are all galactolipids glycolipids
yes
what is the structure of galactolipids like (2 things)
1 or 2 galactose units ar C3, acyl chains at C1 C2
what are the acyl chains of galactolipids derived from
inoleic acid
what are 3 special structures that chaaracterize archae membrane lipids
- phospholipids
- ether-linked
- branched isoprenoid chains
what is special about a lot of archae
extremophiles (heat acid salt)
what is special about the ether linkages in archae membrane lipids
they are more resistant to hydrolysis in the presence of heat/low pH
what kind of linkages are in archae membrane lipids
ether
what kind of lipid is an archae membrane lipids
phospholipid
what kind of chains are in archae membrane lipids
branched isoprenoid
what is significant for using isoprenoid chains with archae
its more rigid so it has more resistance to degradation
what are sterols
rigid membrane lipids with fused ring systemd
what is the common sterol in humans
cholesterol
what is the length of sterols like
equivalent to a 16:0 fatty acyl group
what would be a sphingosine with a phosphocholine or phosphoethanolamine
sphingomyelin
what would be a sphingosine with a monosaccharide (glucose or galactose)
cerebrosides
what would be a sphingosine with a neutral oligosaccharide structure (2 or more sugars)
globosides
what would be a sphingosine with an oligosaccharide with at least one sialic acid
ganglioside
why can some compounds be classified as either lipid or lipid-associated
because of their overall hydrophobicity
