Biochemistry of Carbohydrates Flashcards
Molecules that occur naturally in living organisms are?
Biomolecules
The four main types of BIOMOLECULES are?
Carbohydrates
Proteins
Nucleic acids
Lipids
The bond mostly found in biomolecules is?
Covalent bond
BIOMOLECULES consists of?
Carbon Hydrogen Nitrogen Phosphorus Oxygen Sulphur
Some functions of carbohydrates are?
They serve as structural component of cell membrane
They serve as a source of fuel and energy
The general molecular formula of carbohydrates are?
(CH2O)n
where n>3
Carbohydrates are_____ or compounds which give these substances on hydrolysis
Polyhydroxy aldehydes or ketones
The three major classes of carbohydrates are?
Monosaccharides
Oligosaccharides
Polysaccharides
Monosaccharides are also called?
Simple sugars
Monosaccharides consist of?
3-7 carbon atoms
Single polyhydroxy aldehyde or ketone unit
Most abundant monosaccharides are the?
6 carbon sugars
Example of 6 carbon sugars are?
D-glucose
Fructose
The monosaccharide structure consists of?
Unbranched, single bonded carbon chain backbone
1 carbon atom attached to an oxygen atom by double bond
The 2 families of monosaccharides are?
Aldoses
Ketoses
Monosaccharides containing aldehydes are called?
Aldoses
Monosaccharides containing ketones are called?
Ketoses
When a carbohydrate reacts, mostly the ___ reacts
OH ion
Molecules with more than one OH group either at the terminal carbon atom(aldose) or second carbon atom (ketose) are called?
Polyhydroxy aldehydes or ketones
The change in optical rotation because of the change in equilibrium between 2 anomers when their corresponding stereo centers interconvert is called?
Mutarotation
Some physical properties of monosaccharides are?
Colourless, crystalline compounds
Soluble in water.
Optically active solutions
Exhibit mutarotation
A carbon that has four different groups or atoms attached to it and has optical activity in solution is called?
Asymmetric or chiral carbon
The designation of a sugar isomer as the D- or L- form is determined by?
The spatial relationship to the parent compound of the carbohydrate family
D- means?
Dexter(right) or dextrorotatory (+)
L- means
Laevus(left)
Levorotatory (-)
A mixture that has equal amounts of D and L isomers, with no optical activity is called?
Racemic or DL mixture
Sugars that differ from one another, only in configuration around one carbon atom or carbohydrates which vary in one position for the placement of the -OH group are called?
Epimers
A sugar whose anomeric carbon is attached to a hydroxyl group that can reduce compounds is called?
Reducing sugar eg maltose & lactose
A sugar whose anomeric carbon is not attached to a hydroxyl group that can reduce compounds is called?
Non-reducing sugar eg sucrose
Either of a pair of chemical compounds whose molecular structures have a non-superimposable mirror-image relationship to each other is called?
An enantiomer
A mixture of equal quantities of two enantiomers, or substances that have dissymmetric molecular structures that are mirror images of one another is called?
Racemic mixture, also called racemate
The main difference between anomers and epimers is that anomers differ from each other in its structure at their ___1___whereas epimers differ from each other at any one of the ___2____ present in their structure
- anomeric carbon
2. Chiral carbons
Carbohydrates that differ from each other in its structure at their anomeric carbon are called?
Anomers
An anomeric carbon may be a?
Hemiacetal or Hemiketal carbon
A carbon that is attached to four different types of atoms or groups of atoms is called?
Chiral carbon (asymmetric carbon)
A carbon derived from the carbonyl carbon (the ketone or aldehyde functional group) of the open-chain form of the carbohydrate molecule is called?
Anomeric carbon
Carbohydrates that are stereoisomer compounds with molecules that are not mirrored images of one another and are not superimposable are called?
Diastereomers
Diastereomers have different?
Physical properties
An aldehyde reacts with an alcohol to form a?
Hemiacetal or acetal ring
An ketone reacts with an alcohol to form a?
Hemiketal or metal ring
