Chapter 7: Carbohydrates and Glycobiology Flashcards
Carbohydrates are produced from …
CO2 and H2O via photosynthesis in plants
This is the smallest carbohydrate
Glyceraldehyde
This is the largest carbohydrate
Amylopectin
Carbohydrates functions:
- energy source and energy storage
- structural component of cell walls and exoskeleton
- informational molecules in cell-cell signaling
When carbohydrates are covalently linked with proteins, this forms …
glycoproteins and proteoglycans
What are the two types Monosaccharides?
Aldoses and Ketoses
An aldose contains an ______ functionality
aldehyde
A ketoses contains a _____ functionality
ketone
What are epimers?
Diastereomers of two sugars that differ only in the configuration around one carbon atom
What is an anomeric carbon?
The formal carbonyl carbon becomes a new chiral center
How to determine if the anomer is alpha or beta?
The formal oxygen becomes a hydroxyl group. The position of the hydroxyl group determines if the anomer is alpha or beta. If the hydroxyl group is on the opposite side of the rings (trans), its alpha. If the hydroxyl group is on the same side as the ring (cis), its beta.
What is the configuration of an anomer is the hydroxyl group is in the cis position?
beta
Six-membered oxygen-containing rings are called …..
Pyranoses
Five-membered oxygen-containing rings are called …
Furanoses
Two sugar molecules can be joined via ____________ between an anomeric carbon and a hydroxyl carbon
Glycosidic bond
What is maltose?
Maltose is a disaccharide made from glucose
Natural carbohydrates are known as …
Polysaccharides
True or False:
Polysaccharides do not have a defined molecular weight
True
What is glycogen?
A branched homopolysaccharide of glucose
What is the function of glycogen in animals?
Functions as the main storage polysaccharide in animals
Glucose monomers form ______ linked chains. (linear forms)
alpha 1, 4
Branch-points with ________ linkers every 8-12 residues
alpha 1, 6
What is Starch?
A mixture of two homopolysaccharides of glucose
Define Amylose
An unbranched polymer of (alpha 1,4) linked residues
Define Amylopectin
Branched like glycogen but the branch-points with (alpha 1,6) linkers occur every 24-30 residues
What is the main storage polysaccharide in plants?
Starch
Glycogen and starch often form _____ in cells
granules
True or False:
Glycogen and amylopectin have one reducing end but many nonreducing ends
True
What are the three types of storage carbohydrates?
- Glycogen
- Amylose
- Amylopectin
Which of the three types of storage carbohydrates is linear?
Amylose
What is the bond used to make a linear storage carbohydrate?
alpha 1,4
Which of the three storage carbohydrate are branched?
Glycogen and amylopectin
True or False:
Only alpha 1,6 linker is used for glycogen and amylopectin
FALSE
Both alpha 1,4 and alpha 1,6 are used in glycogen and amylopectin
What is cellulose?
An unbranched homopolysaccharide of glucoes
Cellulose has ____ linkers
Beta 1,4
This is the most abundant polysaccharide in nature
Cellulose
