Upgrade to remove ads
Terms in this set (67)
• a major source of energy from
• made from the elements carbon, hydrogen, and oxygen
• also called saccharides, which means "sugars"
How carbs like glucose produced?
photosynthesis in plants
• are synthesized in plants from CO2, H2O, and energy from the sun
When oxidized in living cells carbohydrates produce ______, ______, and energy
the simplest carbohydrates
consist of two monosaccharides
consist of three to eight carbon chains with one carbon in a carbonyl group
have hydroxyl groups on all carbons except the carbonyl carbon
monosacharides containing an aldehyde group
Monosacharides containing a ketone group
How are monosaccharides classified?
the number of carbon atoms present.
triose (three C atoms)
tetrose (four C atoms)
pentose (five C atoms)
hexose (six C atoms)
An aldopentose is a ____-carbon saccharide with an aldehyde group.
A ketohexose is a ____-carbon saccharide with a ketone group.
is a two-dimensional representation of a three-dimensional molecule
• places the most highly oxidized carbon group at the top
• uses vertical lines in place of dashes for bonds that go back
• uses horizontal lines in place of wedges for bonds that
the same number of atoms
but are arranged differently in space
• a nonsuperimposable mirror image
Molecules are chiral when they have
at least one or more chiral carbon atoms
• a carbon atom, bonded to four different groups
• nonsuperimposable mirror images
Have the same molecular formula but different structures
Same formula but structurally different
Atoms are connected in the same order but differ in spatial arrangement.
Hydorxyl on chiral carbon on the Right
Hydroxyl on chiral carbon on the Left
Nonsuperimposable mirror images
Not mirror image
Manose is an epimer of glucose on ___.
Differ at one of several asymetric carbon atoms
Isomers that differ at a new asymmetric carbon atom formed on ring closure
• found in fruits, corn syrup, and honey
• an aldohexose with the formula C6H12O6
• known as dextrose and blood sugar in the body
• a building block in sucrose, lactose, maltose, and in polysaccharides such as cellulose and glycogen
obtained from sucrose, is
• a ketohexose with the formula C6H12O6
• the sweetest of the carbohydrates, twice as sweet as sucrose
The sweet taste of honey comes from the monosaccharides D-________ and D-________.
• is an aldohexose, C6H12O6
• is not found free in nature
• is obtained from the disaccharide lactose
• has a similar structure to glucose except for the — OH on carbon 4
enzyme(s) needed to convert galactose to glucose is missing.
glucose has a normal blood level of _______ mg/dL
-pancreas is unable to produce sufficient quantities of insulin
- thirst and excessive urination
• increased appetite and weight loss
In older adults, diabetes is sometimes a consequence of excessive weight gain.
Diabetes allows glucose levels in the body fluids to rise as high as _____ mg/dL of plasma
• the blood glucose level decreases to levels as low as 40 mg/dL
• low blood sugar may occur as a result of an overproduction of insulin by the pancreas
• symptoms may appear, such as dizziness, general weakness, and muscle tremors
produced from the reaction of a carbonyl group and a hydroxyl group in the same molecule.
AChiral can't be _________.
The most stable forms of pentose and hexose sugars are five- or six-atom rings.
Haworth Structures of Monosaccharides
These rings, known as Haworth structures, are produced from the reaction of a carbonyl group and a hydroxyl group in the same molecule.
Mutarotation α- and β-D-Glucose
When placed in solution,
• cyclic structures open and close
• α-D-glucose converts to β-D-glucose and vice versa
• at any time, only a small amount of open chain forms
• is a ketohexose
• forms a five-atom ring structure with carbon 2 at the right corner of the ring
• forms when the — OH group on carbon 5 reacts with carbon 2 in the carbonyl group
Monosaccharides in solution
• have small amounts of the open-chain form present
• have an aldehyde group with an adjacent hydroxyl group that can be oxidized to carboxylic acid by an oxidizing agent such as Benedict's
• are produced from the oxidation of the aldehyde form as Cu2+ is reduced to Cu2O
• are named by replacing the ose ending of the monosaccharide with onic acid
A carbohydrate that reduces another substance (such as the open chain form of D-glucose)
Oxidation: Fructose to Glucose
Fructose, a ketohexose, rearranges to form glucose and is then oxidized in Benedict's.
Reduction of Monosaccharides
The reduction of the carbonyl group in monosaccharides
• produces sugar alcohols, which are also called alditols
• converts D-glucose to the sugar alcohol D-sorbitol
• are named by replacing the ose ending of the monosaccharide with itol
• include D-sorbitol, D-xylitol from D-xylose, and D-mannitol from D-mannose
• are used as sweeteners in many sugar-free products such as diet drinks and sugarless gum
consists of two monosaccharides linked together
• is formed when two monosaccharides combine in a dehydration reaction
glucose + glucose
maltose + H2O
glucose + galactose
lactose + H2O
glucose + fructose
sucrose + H2O
most common disaccharides
maltose, lactose, and sucrose
• a disaccharide also known as malt sugar
• composed of two D-glucose molecules
• obtained from the hydrolysis of starch
• used in cereals, candies, and brewing
• found in both the α and β forms
inked by an α-1,4-glycosidic bond formed from the α — OH on carbon 1 of the first glucose and — OH on carbon 4 of the second glucose.
is a disaccharide found in milk and milk products
• makes up 6-8% of human milk and about 4-5% of cow's milk
The bond in lactose is a β-1,4- glycosidic bond because the — OH group on carbon 1 of β-D-galactose forms a glycosidic bond with the — OH group on carbon 4 of a D-glucose molecule.
Sucrose, or table sugar,
• is obtained from sugar cane and sugar beets
• cannot form an open chain and cannot be oxidized
• cannot react with Benedict's reagent and is not a reducing sugar
• marketed as Splenda
• made from sucrose by
replacing some of the hydroxyl groups with chlorine atoms
• marketed as NutraSweet or Equal
• a noncarbohydrate sweetener made from aspartic acid
and a methyl ester of the amino acid phenylalanine
Blood types A, B, AB, and O are determined by terminal ___________ attached to the surface of red blood cells.
Blood type O
has three common terminal monosaccharides:
N-acetylglucosamine, galactose, and fucose
Blood type A
contains the same three monosaccharides, but in addition, a molecule of N-acetylgalactosamine is attached to galactose in the saccharide chain
Blood type B
also contains the same three monosaccharides, but in addition, a second molecule of galactose is attached to the saccharide chain
Blood type AB
consists of the same monosaccharides found in blood types A and B
contains the three common monosaccharides, produce antibodies against blood types A, B, and AB—they are universal donors
blood types A, B, and AB can receive type ___ blood
contains all the terminal monosaccharides, produce no antibodies to type A, B, or O blood—they are universal recipients
Sets with similar terms
An introduction to General, Organic, and Biologica…
4: Carbohydrate Structure and Function
Other sets by this creator
Lewis Chapter 42 Upper GI NCLEX practice questions
Lewis Chapter 42: Lower GI
Lewis 42 Lower GI Problems
Chapter 45: Renal and Urologic Problems Lewis: Med…