Lecture 2-Carbohydrates Flashcards
What are carbohydrates?
Biological molecules containing C, H & O
What is the empirical formula of carbohydrates?
Cm(H20)n
What are the functions of carbohydrates?
Provide a rapid + available supply of energy
Sugar phosphate backbone in DNA
Form markers on the cell surface ( Blood group markers)
What is the general formula for MONOSACCHARIDES?
(CH20)n
What is an OLIGOSACCHARIDE?
Polymer of 3-20 monosaccharides
What is a POLYSACCHARIDE?
+20 monosaccharides
Examples of monosaccharides?
Glucose, Ribose, Fructose
What do monosaccharides tend to do?
Provide INSTANT energy
How many C atoms do a monosaccharide tend to have?
3-10
What functional groups do monosaccharides contain?
Aldehyde/Ketone & hydroxyl group
What makes a monosaccharide “deoxy”?
The replacal of a hydroxyl group with a H
What are the 2 forms of stereoisomerism in monosaccharides?
D and L
Stereoisomers have the same……
chemical formula, orders, types of bonds
Stereoisomers are non-overlapping mirror images so they have different…..
spatial arrangements, biological functions
Stereoisomers require what?
A CHIRAL centre
If the OH on a fichier projection is to the right, what type stereoisomer is it?
D
How do monosaccharides tend to exist?
As open-chain / ring structures (via covalent bonds)
What is CYCLIZATION?
The OH on the 2nd to last C bonds to a carbonyl group
Cyclization of an aldose sugar forms what?
A hemiacetal
Cyclization of a ketose sugar forms what?
A hemiketal
Cyclization of D-glucose forms what?
D-glucopyranose
Why are there 2 hemiacetal products of D-glucopyranose?
The OH group can attach either side of the planar C=0 group
What type of bonds do glucose have?
7 energy rich bonds
When are glucose bonds broken down?
During cellular respiration (releasing energy stores as ATP)
Where is fructose found?
Fruits,honey,berries
What type of structure does fructose form?
A FURAN-BASED RING STRUCTURE