Carbohydrates Flashcards
- most abundant and widespread organic substances in nature, and they are essential constituents of all living
things. - are formed by green plants from
carbon dioxide and water during the process of photosynthesis.
Carbohydrates ( C H 2 0 ) n
serve as energy s o u r c e s and as
essential structural components in organisms.
• It is build up of sugars.
Other Functions of Carbohydrates
• As Lubricant of skeletal joints
• As major components of the cell
wall o f bacteria and of the soft cell
coats in animal tissues.
• They provide adhesion between
cells.
• Degradation products act as
“promoters” or “catalysts”.
Carbohydrates
WHAT ARE THE TWO MAJOR BIOLOGICAL FUNCTIONS OF CARBOHYDRATES?
- As storage from fuel
- Glucose, Starch & Glycogen
- 1gram of Carbohydrates will yield
4kcal of energy - As structural elements
- Cellulose, Acid mucopolysaccharides
and proteoglycans
(simple sugars)
“are those which cannot be hydrolyzed further into simpler forms”
• (CH,O) in which n is any integer from 3 to 7
• The simplest carbohydrate, have a backbone of from 3 to 7carbon.
• They are colorless, crystalline solids; very soluble in water, slightly soluble in ethanol, and insoluble in nonpolar solvents.
-ose indicates a carbohydrate; tri-, tetr-, pent- and so forth indicate the number of carbon atoms in the chain
Monosaccharide
sugars which yield two molecules of the same or different molecules of monosaccharide on hydrolysis
Dissacharides
yield 3 to 6 monossacharide units on hydrolysis
Oligosaccharides
• Yield more than 6 units of monosaccharide’s on hydrolysis
Polysaccharides (Glycan)
- polymers of same monosaccharide units
-Examples: starch, glycogen, inulin, cellulose, dextrin, dextran
Homopolysaccharides (Homoglycans)
show sugars in their open chain
form. In a ___________, **the carbon atoms of a sugar molecule are connected vertically by solid lines, while carbon-oxygen and carbon-hydrogen bonds
are shown horizontally.
Fisher projections
- polymer of different monosaccharide units or their derivatives
- Ex: Mucopolysaccharide (Glycosaminoglycan “GAG”)
Heteropolysaccharides (Heteroglycans)
- polymer of different monosaccharide units or their derivatives
- Ex: Mucopolysaccharide (Glycosaminoglycan “GAG”)
Heteropolysaccharides (Heteroglycans)
It can be alpha or beta form.
a. Haworth projections are often used to depict sugars in their cyclic forms.
b. Chair conformation
Cyclic form
what are the 2 forms of sugar?
-open form
-cyclic form
known as “aldose” if sugar has a presence of aldehyde. R-CHO
Aldehyde
Known as “ketose” if sugar has a presence of R-COR
Ketone
the branch of chemistry concerned with the three-dimensional arrangement of atoms and molecules and the effect of this on chemical reactions.
Stereochemistry
it is the linkage of atoms of the same element into longer chains. ex: Carbon to Hydrocarbon
Catenation
a chemically organic functional group composed of a carbon atom double bonded to an oxygen (C=O)
Carbonyl group
is a carbon atom bonded with four different compounds (groups) at the same time
chiral carbon
are chiral molecules that are mirror
images of one another. The molecules are non-superimposable on one another. This means that the molecules cannot be placed on top of one another and give the
same molecule.
Enantiomers
Each of two isomers with different configurations of atoms around one of several asymmetric carbon atoms present.
EPIMERS
Combination of alpha and Beta
are diastereoisomers of cyclic forms of sugars or similar molecules differing in the configuration at the anomeric carbon (C-1 atom of an aldose or the C-2 atom of a 2-ketose). The cyclic forms of carbohydrates can exist in two forms, a- and B- based on the position of the substituent
ANOMERS
is the change in specific rotation of a chiral compound due to epimerization.
-the ongoing interconversion between anomers of a particular carbohydrate to form an equilibrium mixture.
Mutarotation
