Biol 4087 Exam 3 part 1 Exam Questions with
Verified Solutions 100% Correct
What are the simplest monosaccharides
carbohydrates?
carbon-based molecules high in hydroxyl groups
what are carbohydrates?
= empirical formula: (CH2O)
What are aldehydes or ketones that contain to or more
monosaccharides? hydroxyl groups
how many carbons are the 3 carbons
smallest
monosaccharides?
Monosaccarides exist in
many isomeric forms
-three carbons: trioses
Monosaccharide -four carbons: tetroses
nomenclature is based on -five carbons: pentoses
carbon-chain length -six carbons: hexoses
-seven carbons: heptoses
-keto group: ketose
Nomenclature is also
based on the identity of
-aldehyde group: aldose
the most oxidized group:
, molecules with identical molecular formulas that differ
What are isomers?
in how the atoms are ordered
molecules that differ in spatial arrangement but not
bonding order
-have either D or L configuration
What are stereoisomers? –can be enantiomers (mirror images of each other)
or
diastereoisomers (not mirror images of each other)
–number possible = 2n where n is the number of
asymmetric carbon atoms
Isomeric forms of
carbohydrates
Most Monosaccharides Interchanging Cyclic Forms
Exist as?
hemiacetal
An aldehyde can react
with with an alcohol to
form a?
hemiketal
A ketone can react with an
alcohol to form a?
called pyranose because of
similarity to pyran
Pyranose Formation
, The open-chain form of glucose
cyclizes when the C-5 hydroxyl
group attacks the oxygen atom
of the C-1 aldehyde group to
How can D-Glucose and form an intramolecular
other monosaccharides hemiacetal.
temporarily form a
pyranose ring? - Two interchanging anomeric
forms of the pyranose ring,
designated α and β, can result;
both in rapid equilibrium with
the open-chain (linear) form
• called furanose because of
similarity to furan
Furanose formation
The open-chain form of
fructose cyclizes to a five-
membered ring when the C-5
How can D-Fructose and
hydroxyl group attacks the C-2
other monosaccharides
ketone to form an
temporarily form a
intramolecular hemiketal. Two
furanose ring?
interchanging anomers are
formed, but only the α anomer
is shown.
The Most Common
Monosaccharides Exist
Primarily in Their Ring
Forms
• covalent linkage formed
What is a O-glycosidic between the anomeric carbon
linkage? atom of a carbohydrate and the
oxygen atom of an alcohol.
Verified Solutions 100% Correct
What are the simplest monosaccharides
carbohydrates?
carbon-based molecules high in hydroxyl groups
what are carbohydrates?
= empirical formula: (CH2O)
What are aldehydes or ketones that contain to or more
monosaccharides? hydroxyl groups
how many carbons are the 3 carbons
smallest
monosaccharides?
Monosaccarides exist in
many isomeric forms
-three carbons: trioses
Monosaccharide -four carbons: tetroses
nomenclature is based on -five carbons: pentoses
carbon-chain length -six carbons: hexoses
-seven carbons: heptoses
-keto group: ketose
Nomenclature is also
based on the identity of
-aldehyde group: aldose
the most oxidized group:
, molecules with identical molecular formulas that differ
What are isomers?
in how the atoms are ordered
molecules that differ in spatial arrangement but not
bonding order
-have either D or L configuration
What are stereoisomers? –can be enantiomers (mirror images of each other)
or
diastereoisomers (not mirror images of each other)
–number possible = 2n where n is the number of
asymmetric carbon atoms
Isomeric forms of
carbohydrates
Most Monosaccharides Interchanging Cyclic Forms
Exist as?
hemiacetal
An aldehyde can react
with with an alcohol to
form a?
hemiketal
A ketone can react with an
alcohol to form a?
called pyranose because of
similarity to pyran
Pyranose Formation
, The open-chain form of glucose
cyclizes when the C-5 hydroxyl
group attacks the oxygen atom
of the C-1 aldehyde group to
How can D-Glucose and form an intramolecular
other monosaccharides hemiacetal.
temporarily form a
pyranose ring? - Two interchanging anomeric
forms of the pyranose ring,
designated α and β, can result;
both in rapid equilibrium with
the open-chain (linear) form
• called furanose because of
similarity to furan
Furanose formation
The open-chain form of
fructose cyclizes to a five-
membered ring when the C-5
How can D-Fructose and
hydroxyl group attacks the C-2
other monosaccharides
ketone to form an
temporarily form a
intramolecular hemiketal. Two
furanose ring?
interchanging anomers are
formed, but only the α anomer
is shown.
The Most Common
Monosaccharides Exist
Primarily in Their Ring
Forms
• covalent linkage formed
What is a O-glycosidic between the anomeric carbon
linkage? atom of a carbohydrate and the
oxygen atom of an alcohol.
