Chem230 exam 4 (part 1)
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Chem230 exam 4 (part 1)
chem 230 exam
Chapter 16 Carbohyrdates Fall 2014
major source of energy from our diet composed of the elements C, H and O
aka saccharides? saccharides means?
carbohydrates are a form of
the simplest carbohydrates
consists of 2 monosaccharides
consist of 3-10 monosaccharides
contains many monosaccharides
basic formula of monosaccharide?
3-6 carbon atoms with a carbonyl group and several hydroxyl groups
monosaccharides with an aldehyde group and many hydroxyl groups
6 C atoms
monosaccharides with a ketone group and many hydroxyl groups
bonded to 4 different things
it is not a chiral carbon if?
it is bonded to 2 of the same thing
ex of chiral objects?
the ___ ___ of chiral compounds cannot be superimposed
take mirror image and rotate, it will match up
achiral structures are
left and right is an example of
examples of chiral objects?
examples of achiral objects?
need ___ carbons to be enantiomers
stereoisomers that are mirror images
stereoisomers that are not mirror images
need chiral carbons
enantiomers are also called
interact with plain polarized light to rotate the plane of the light in opposite directions
interaction with polarized light is called
what distinguishes isomers?
same formula, different structure
mix of 2 enantiomers, mirror images around that carbon
racemic mixtures are an
equal mix of 2 enantiomers
fischer projections always end in
places the most oxidized group at the top
most oxidized group in fischer projections?
aldehyde or ketone--placed at the top
OH group on left =
OH group on right =
horizontal lines? vertical lines?
back away from you
most oxidized carbon is always found where on a fischer projection?
at the top
tells you which way it bends to polar light
L and D
how do you determine L or D?
go to lowest chiral carbon
structure of D glucose?
with ketones CH2OH is found?
on top and on bottom
determined by number of chiral carbons
found in fruits, corn syrup and honey
known as blood sugar in the body
glucose has a normal blood level of
is a ketohexose
the sweetest carb found in fruit juices and honey
is an aldohexose
has similar structure to glucose except for the -OH on carbon 4
the prevalent form of monosaccharides with 5 or 6 carbon atoms
when do cyclic structures form?
when the hydroxyl group on C5 reacts with the aldehyde group or ketone group
1st carbon used to determine alpha or beta
OH is down on anameric carbon?
OH is up on anameric carbon?
what makes up a hemiacetal?
aldehyde + alcohol
ketone plus alcohol is?
hemiketals have no __ on central atom
glucose and galactose differ only in the orientation of ?
one hydroxyl group
does not form a positive benedicts test
3 reducing sugars?
the aldehyde groups of aldoses are oxidized by benedicts reagent which is?
an alkaline copper (II) solution
when reducing sugars what goes from what?
copper 2 goes to copper 1
fructose gives a ___ benedicts test
goes through a reaction where is becomes an aldehyde
when an aldehyde is oxidized what happens?
carb acid reacts with copper for benedicts and copper gets reduced
all monosaccharides and disaccharides except sucrose are
can isomerize to aldoses and react also
the most important reduced sugar is
involves the carbonyl group and produces sugar alcohols or alditols
reduction of monosaccharides
when reducing monosaccharides the top C goes to
when oxidizing monosaccharides the top group goes to
C=0 and OH bonded to C
glucose + glucose =
glucose + galactose =
glucose + fructose =
disaccharide of beta-D-galactose and alpha or beta-D-glucose
found in milk and milk products
the main carb in milk, which is composed of both a cyclic hemicetal and a cyclic acetal
aka table sugar
in order for lactose to be used as an energy source galactose must be converted to a phosphorylated glucose molecule. when enzymes necessary for conversion are absent, the genetic disease ___ results
consists of beta-D-glucose and beta-D-fructose
has a beta-1,2-glycosidic bond
polymers of D-glucose that include glycogen
made of alpha-D-glucose
made of beta-D-glucose
a polymer of alpha-D-glucose molecules and is linked by alpha-1,4 glycosidic bonds
amylose is a
has a alpha-1,4-glycosidic bond between glucose units and a alpha-1,6 bond to branches
the polysaccharide that stores alpha-D-glucose in muscle
a polysaccharide of glucose units in unbranched chains
cannot be digested by humans