Haworthprojection formula - is a two-dimensional structural notation that specifies the three-dimensional structure of a cyclic form of a monosaccharide.
Alpha and Beta Configuration
Alpha or Beta configuration is determined by the
position of the —OH group on C1 relative to the
CH2OH group that determines D or L series.
Beta configuration, both of these groups point in the same direction
In an Alpha configuration, the two groups point in opposite directions.
Five important reactions of monosaccharides
Oxidation to acidic sugars
Reduction to sugaralcohols
Glycoside formation
Phosphateester formation
Aminosugar formation
Oxidation to acidicsugars - The redox chemistry of monosaccharides is closely linked to the alcohol and aldehyde functional groups present in them.
Oxidation can yield three different types of acidic sugars depending on the type of oxidizing agent used:
Nadagdagan oxygen, nagiging acidic ang sugar
Reduction to sugaralcohols - The carbonyl
group in a monosaccharide (either an aldose
or a ketose) is reduced to a hydroxyl group
using hydrogen as the reducing agent.
A glycoside - is an acetal formed from a
cyclic monosaccharide by replacement of the
hemiacetal carbon -OH group with an -OR
group.
- Papalitan ng OR ang OH
The general name for monosaccharide acetals is glycoside.
Blood Types and Monosaccharides
Human blood is classified into four types: A ,
B , AB , and O :
The biochemical basis for the various blood types involves monosaccharides present on plasma membranes of redblood cells
The monosaccharides responsible for blood groups are Dgalactose and its derivatives
. Phospateester formation
The hydroxyl groups of a monosaccharide can react with inorganic oxyacids to form inorganic esters.
Phosphate esters of various monosaccharides are stable in aqueous solution and play important roles in the metabolism of carbohydrates
AminoSugar Formation
An amino sugar - one of the hydroxyl groups of a monosaccharide is replaced with an amino group
Amino sugars and their N-acetyl derivatives are important building blocks of polysaccharides.
Two monosaccharides can react to form -
disaccharide
glycosidic linkage - the bond that links the two monosaccharides of a disaccharide (glycoside) together
Cellobiose - is produced as an intermediate in
the hydrolysis of the polysaccharide cellulose.
Cellobiose contains two b - D-glucose monosaccharide units linked through a b (1—4) glycosidic linkage.
cannot be digested by humans
(beta1 - 4)
Maltose - often called malt sugar, is produced
whenever the polysaccharide starch breaks
down, as happens in plants when seeds
germinate and in human beings during
starch digestion.
Structurally, is made up of two D- glucose units, one of which must be a-D- glucose.
Kaya I-digest ng human body ang alpha ( 1 - 4 )
Lactose - is made up of b-D-galactose unit and a b-D-glucose unit joined by a b(1-4) glycosidic linkage.
- is the major sugar found in milk
- a condition in which people lack the enzyme lactase needed to hydrolyze lactose to galactose and glucose.
- hydrolyzes b(1-4) glycosidic linkages.
Deficiency of lactase can be caused by a genetic defect, physiological decline with age, or by injuries to intestinal mucosa.
Sucrose - (table sugar): The most abundant of
all disaccharides and found in plants.
It is produced commercially from the juice of
sugar cane and sugar be
is a nonreducing sugar.ets
Combination of alpha d-glucose and beta d fructose, nag link sila sa beta (1-2)
A polysaccharide - is a polymer that contains
many monosaccharide units bonded to each
other by glycosidic linkages.
Homopolysaccharide - is a polysaccharide in which only one type of monosaccharide monomer is present.
Heteropolysaccharide - is a polysaccharide in which more than one (usually two) type of monosaccharide monomer is present.
Starch - that is a storage form for monosaccharides
and is used as an energy source in cells.
- is a homopolysaccharide containing
only glucose monosaccharide units.
- It is the energy-storage polysaccharide in
plants (plant-based carbs ang starch )
Amylopectin - the other polysaccharide in
starch, has a high degree of branching in its
polyglucose structure.
All of the glycosidic linkages in starch (both
amylose and amylopectin) are of the a type
Glycogen
like starch, is a polysaccharide containing only glucose units.
Liver cells and muscle cells are the storage sites for glycogen in humans.
is an ideal storage form for glucose.
Cellulose
Linear homopolysaccharide with b (1 4) glycosidic bond Humans don’t have enzymes that hydrolyze b (1 4) - so humans can not digest cellulose -- animals also lack these enzymes but they can digest cellulose because they have bacteria in their guts to hydrolyze cellulose
It serves as dietaryfiber in food-- readily absorbs water and results in softer stools.
Chitin
Similar to cellulose in both function and structure
Linear polymer with all b (1 4) glycosidic linkages - it has a N-acetyl amino derivative of glucose
Function is to give rigidity to the exoskeletons of crabs, lobsters, shrimp, insects, and other arthropods.
Acidic polysaccharides - polysaccharides with a repeating disaccharide unit containing an amino sugar and a sugar with a negative charge due to a sulfate or a carboxyl group.
Structural polysaccharide present in connective tissue associated with joints, cartilage, synovial fluids in animals and humans
Hyaluronic acid:
Alternating residues of N-acetyl-b-D- glucosamine and D-glucuronic acid.
Highly viscous - serve as lubricants in the fluid of joints and part vitreous humor of the eye.
Heparin:
An anticoagulant-prevents blood clots.
Glycolipid is a lipid molecule that has one or more carbohydrate (or carbohydrate derivative) units covalently bonded to it.