BCM12 Flashcards
alpha d- glucopyranose (1->2) beta- d frutofuranose
sucrose
alpha - d glucopyranosyl (1->4) alpha- d- glucopyranose
maltose
beta- d galactopyranose (1->4) alpha/beta- d- glucopyranose
lactose
what is raffinose?
storage oligosaccaharide found in legumes
alpha (1->6) galactosyl sucrose
raffinose
raffinose
alpha (1->6) galactosyl sucrose
what is needed to digest alpha 1->6 glycosidic bonds?
alpha gal
what do legumes cause flatulance?
humans lack alpha Gal to digest rafinose bond so fermented by microorganisms creating methane and c02 - f
what are abo blood group antigens?
o linked oligosaccharides on rbc
how do A and B blood antigens differ
A has a alpha d acetylgalactosamine where b has a alpha d galactose
what are the main sugars in the blood group antigens?
alpha - l fructose
alpha/beta d - galactose
beta d acetyl glucosamine
alpha d acetyl galactosamine
what linkage do the blood antigens have?
alpha 1->3
how does H/O blood group antigen differ from A and B?
has one less sugar molecule of the variety that is fdifference between A and B (only 4 sugars)
what are glycosyl transferases?
enzymes that catalyse links between sugar monomoers
what are lecitns?
proteins that bind carbohydrates
what is ricin?
a very toxic lectin
what are lectins domains?
bind cell surface glycoproteins
give examples of 3 sugar homopolymers?
starch
cellulose
glucans
give an example of a sugar heteropolymer, describe
hyaluronan
d glucuronic acid adn n acetyl glucosamine
where is hyaluronon found?
synovial fluid, joints
stops bone erosion
jelly in eyes
beta (1->4) glucan (1->4 linkage) - ubranched
Cellulose
describe celluose
beta (1->4) glucan, unbranched highly ordered rod shaped cystalline resistent to heat damage found in gossyplum - cotton balls
what gives cellulose such good tensile strength?
extensive h bonding
what is chitin?
beta (1->4) hompolymer of n acetyal glucosamine
where is chitin found?
insect exoskeleton
fungal cell wall
very abundant polymer
second only to cellulose
what is starch?
storage carbohydrate
mix of glucans
amylose and amylopectin
what is amylose?
(1->4) glucan, bent hollow left handed helix.
what is the basis of the starch iodine test?
helical arrangement of amylose
I3- and I5- fit inside amylose coils
light cant pass through due to electronorbitals
what are amylopectin and glycogen?
branched starches with alpha 1->4 glucam with alpha (1->6) branches
what is the animal equivalent of amylopectin?
glycogen
what do many modified polysaccharides act as?
hydrocolloid gels and gums
what is alignate
anionic polysaccahride
heteropolymer
beta 1-4 linked d mannuronate and alpha 1-4 linked l guluronate
found in brown algae
what is agar
found in red algae
mix of polysaccharide agarose 1-3 beta d galactopyranose 1-4 -3-6 anyhydro alpha l galactopyranose and agropectin
microbiology plates
(1->3) beta d galactopyranose (1->4) -3-6 anyhdro alpha l galactopyranose and agropectin
agar
beta (1->4) linked d mannuronate and alpha (1->4) l glucoronate
alignate
what are pectins?
modified polysaccharides that glue plant cells together
what are the two components of pectic acid
homogalacturonan
and rhamnogalacturonan
what is homogalacturonan
alpha 1 -4 linked galacturonic acid residues
can be methyl esterified or acetylated
hydrophobic interactions
what is pectic acids role?
plats similar role to hyaluronan = very hydrophillic
borate and calcium cross links
thickener in jams
what are hydrocolloid gels used in
loads of things foods, pharmaceuticals paper thickener ice cream
what are beta 1-4 glycans used for
structural
what are alpha 1-4 glycans used for
storage
