Week 8- Carbohydrates Flashcards
What is the chemical formula for many monosaccharides?
C_n(H_2O)_n
For example, glucose has the formula C_6H_12O_6.
What are the primary functions of carbohydrates?
- Energy source and storage (e.g., glucose, starch)
- Structural components (e.g., cellulose)
- Information carriers
- Covalently linked with proteins and lipids
What are monosaccharides?
The simplest carbohydrates containing between 3 and 7 carbons
What is a carbonyl group?
A functional group consisting of a carbon atom double-bonded to an oxygen atom.
What are the classifications of monosaccharides based on the number of carbons?
- Triose (3 carbons)
- Tetrose (4 carbons)
- Pentose (5 carbons)
- Hexose (6 carbons)
- Heptose (7 carbons)
What is the difference between constitutional isomers and stereoisomers?
- Constitutional isomers differ in the order of attachment of atoms
- Stereoisomers have the same order but differ in spatial arrangement
What are enantiomers?
Stereoisomers that are non-superimposable mirror images.
What defines a chiral carbon atom?
A carbon atom that has four different groups bonded to it.
What are diastereomers?
Stereoisomers that are not mirror images and have different physical properties.
What are epimers?
Two sugars that differ only in the configuration around one carbon atom.
What is cyclisation in the context of monosaccharides?
The formation of a cyclic structure from a linear monosaccharide.
What are pyranoses?
Six-membered oxygen-containing rings formed from cyclisation of hexoses.
What are furanoses?
Five-membered oxygen-containing rings formed from cyclisation of pentoses.
What are glycosidic bonds?
Bonds formed when monosaccharides are linked to other molecules.
What are the two types of glycosidic bonds?
- N-glycosidic bond: between an anomeric carbon atom and a nitrogen atom
- O-glycosidic bond: between an anomeric carbon atom and an oxygen atom
What are disaccharides?
Carbohydrates formed from two monosaccharides linked by O-glycosidic bonds.
What is starch?
The main storage polysaccharide in plants.
What are the two components of starch?
- Amylose
- Amylopectin
What is glycogen?
The main storage polysaccharide in humans and animals.
What is cellulose?
A linear polysaccharide of glucose that is a primary structural component in plant cell walls.
What are glycosaminoglycans (GAGs)?
Linear polysaccharides of repeating disaccharide units, major components of the extracellular matrix.
What are proteoglycans?
Proteins with one or more GAGs covalently attached.
What is the role of glycoproteins?
Proteins that carry one or more oligosaccharide chains and are involved in various cellular functions.
What is the significance of protein glycosylation?
The attachment of carbohydrates to proteins, important for cell-cell communication.
Fill in the blank: Most naturally occurring sugars are ______.
D isomers
True or False: Cellulose can be digested by humans.
False
