CARBOHYDRATES II Flashcards
Two monosaccharides can react to form___
Disaccharides
The bond that links the two monosaccharides of a disaccharide (glycoside) together is called a
Glycosidic linkage
forms C-O-C bond: via condensation: water will be elicited during the reaction, then will bond into O2
Monosaccharides that has a cyclic form will react w/ alcohol to form a glycoside
____1- 4: both (C1-C4) pointing down prior to linkage
____1- 4: C1 (up), of C4 (down)
Alpha
Beta
Not all have disaccharides have beta and alpha 1-4 linkage, others can have diff types of C number or linkage
C1-C4: C units to be used in glycosidic linkage, commonly used
Beta 1-4: humans do not have an enzyme to break down this type of linkage
Types of Disaccharides:
From breakdown of cellulose
Produced as an intermediate in the hydrolysis of the polysaccharide cellulose
Contains two beta-D-glucose monosaccharide units linked through a beta(1-4) glycosidic linkage
Cellobiose
cannot be digested by humans; no enzyme to breakdown the said glycosidic linkage; it will be excreted undigested
Monomer unit: glucose
Types of Disaccharides:
Often called malt sugar, it’s produced whenever the polysaccharide starch breaks down, as happens in plants when seeds germinate and in human beings during starch digestion.
Breakdown of starch: baby food, cereals, wheat, malt products. Reducing sugar
Similar w/ cellobiose in terms of monomer units used to form this
is made up of two D-glucose units, one must be alpha-D-glucose.
Maltose
Because OH needs to be pointed downward
Chemical formula: C12H22O11 (C6H12O6 + C6H12O6)
H2O was released during the reaction, making H22 and O11
Can be digested by humans via maltase (enzyme)
Alpha 1-4: OH bond is pointing downwards
Acidic condition is needed for breakdown of maltose
Types of Disaccharides:
Made up of beta-D-galactose unit and a b-D-glucose unit joined by a b(1-4) glycosidic linkage.
Beta: OH and CH2OH are both pointing upward
Principal CHO in minerals
is the major sugar found in milk.
Lactase: enzyme involved; hydrolyzes beta 1-4 glycosidic linkage
Lactose
Human milk: 7-8%, Cows milk: 4-5% lactose
D-galactose is 1st monomer unit; bcs C-1 OH is upward
D-glucose is the 2nd monomer unit: C-4 OH is downward and used for the bonding
Lactose intolerance: a condition in which people lack the enzyme lactase needed to hydrolyze lactose to galactose and glucose
Can cause stomach cramps, gastric discomforts, diarrhea, gas
TRUE OR FALSE:
Enteric bacteria in the body can ferment lactose and produces lactic acid in intestinal tracts
TRUE
Types of Disaccharides:
Also called saccharose, best known disaccharides
Most abundant of all disaccharides and found in plants
Produced commercially from the juice of sugar cane and sugar beets
Only nonreducing sugar
Provides major portion of CHO intake for many indivs
Sucrase: enzyme responsible of hydrolysis of glycosidic linkage
Needed to breakdown glucose molecule w/c is present in the body
Sucrose
Only exist in 1 form: solid or aqueous solution
Monosaccharide unit: Alpha-D-glucose and Beta-D-Fructose
Head-to-head glycosidic linkage: aligned
Alpha-Beta 1-2 configuration
Linkage bet C1-C5 glucose: pyranose and C2-C6 fructose: furanose
C2: utilized to have close cyclic ring for monosaccharides
Sucrose, maltose, factose: can be broken down by the human body
Formed bcs of the polymer chain
is a polymer that contains many monosaccharide units bonded to each other by glycosidic linkages.
Can be classified based on the type of monosaccharide/ monomer unit present in the structure
Polysaccharides (glycans)
starch, glycogen, cellulose, chitin, acidic polysaccharides, glycolipids, glycoproteins
A if only the first statement is true
B if only the second statement is true
C if both of the statements are true
B if neither of the statements is true
- A homopolysaccharide is a polysaccharide in which several types of monosaccharide monomer is present
- A heteropolysaccharide is a polysaccharide in which more than one (usually two) type of monosaccharide monomer is present. .
B
Homo: only has 1 type of monosaccharide
Polysaccharides formed thru maltose and cellobiose: both are form glucose
Hetero: 2 types of monosaccharide
Polysaccharides formed thru lactose
2 Types of Polysaccharide based on Chain
Straight/ Linear/ Unbranched Chain: just straight
Branched: 2 different glycosidic linkage found in structure
Types of Polysaccharides:
energy-storage polysaccharide in plants
A storage polysaccharide is a polysaccharide that is a storage form for monosaccharides and is used as an energy source in cells/ plants.
Homopolysaccharide containing only glucose monosaccharide units.
Starch
2 types of polysaccharides could be isolated in starch: amylopectin and amylose
Amylopectin, the other polysaccharide in starch, has a high degree of branching in its polyglucose structure
Branched chain polymer: Alpha 1-6 glycosidic bond
Straight chain: Alpha-1-4
80-85% of starch; 300k amu, 100k glucose unit
Amylose: straight chain polymer of starch
Alpha 1-4 is the glycosidic bond/ linkage
15-20% of starch, 50,00 amu, 1k glucose unit
A if only the first statement is true
B if only the second statement is true
C if both of the statements are true
B if neither of the statements is true
All of the glycosidic linkages in starch (both amylose and amylopectin) are of the Alpha type
Humans can hydrolyze/ digest Alpha linkage but not Beta linkage
C
Types of Polysaccharides:
A polysaccharide containing only glucose units
Storage form of polysaccharide for humans
Branched chain polymer: Alpha 1-4 linkage (straight): Alpha 1-6 linkage (branches)
Liver cells and muscle cells are the storage sites for glycogen in humans.
Glycogen
is an ideal storage form for glucose
3M amu (molecular mass); 1M glucose units
3x times more highly branched than amylopectin in starch
_____ is the storage of excess glucose in the form of glycogen
_____ is the breakdown / hydrolysis of glycogen into glucose
Glycogenesis
Glycogenolysis
