Naming type shii
A carbohydrate with aldehyde functionality is called what? What about ketone?
Aldose and Ketose
What is a six-membered oxygen-containing ring and a five-membered oxygen-containing ring called?
(6) Pyranose after the pyran ring structure.
(5) Furanoses after the furan ring structure.
What charge do glycoaminoglycans have?
Negative charge.
What are proteoglycans?
They are sulfated glycosaminoglycans attached to a large rod-shaped protein in cell membranes.
What grade are we getting on this exam?
100!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!
What do horizontal and vertical bonds represent?
Horizontal bonds are pointing towards you (wedge). Vertical bonds are pointing away from you (dash).
What are epimers and how do you distinguish epimers of glucose?
Epimers are stereoisomers that differ at only one chiral center.
Mannose has a epimer at C-2
Galactose has a epimer at C-4
Fructose is the ketose form of glucose
What are glycosaminoglycans?
They are linear polymers of repeating disaccharide units. Monomer is either N-acetyl-glucosamine or N-acetyl-galactosamine.
What are the main components of the extracellular matrix?
What are the ELP selectins?
E: Epithelial
L: Leukocyte
P: Platelet
What is the difference between homopolysaccharides and heteropolysaccharides?
Homopolysaccharides have one monomer unit.
Heteropolysaccharides have multiple monomer units.
It is a linear homopolysaccharide of N-acetylglucosamine. Found in cell walls in mushrooms and exoskeletons of insects, spiders, crabs, etc.
What is a glycoprotein?
A protein with small oligosaccharides attached. The carbohydrate is attached via its anomeric carbon to amino acids on the protein.
What do proteoglycan aggregates cover? Why?
They cover joint surfaces like articular cartilage. Reduces friction and load balancing.
what is the basic nomenclature of carbohydrates?
It is the number of carbon atoms in the carbohydrate + ose. Ex: Three carbons = triose
What are hemiketals and hemiacetals?
Hemiacetals are aldehydes that are attacked by alcohols.
Hemiketals are ketones that are attacked by alcohols.
What is the difference between the linkages in amylose and amylopectin and what do these linkages cause?
Amylopectin is branched like glycogen (alpha 1 -> 6) (branching)
What does heparin do?
It prevents blood clotting by activating protease inhibitor antithrombin.
what role do oligosaccharides play in cell recognition?
Many oligosaccharides are attached to glycoproteins or glycolipids on the outer cell membrane. These oligosaccharides stich out into the extracellular space and act as identification markers.
Which glycosaminoglycan doesn't use iduronic or glucuronic acid?
Keratan Sulfate
How is the L/D notion determined?
Determines by looking at the hydroxyl group on the most distal chiral carbon from the carbonyl carbon.
Describe the steps to cyclization.
1. Nucleophilic alcohol attacks the electrophilic carbonyl.
2. The linear carbohydrate forms a linear structure.
3. The carbonyl carbon is then reduced to an alcohol
4. The orientation of the alcohol around the carbon is variable and transient.
What are glycolipids? What do they do in vertebrates and gram-negative bacteria?
They are lipids with covalently bound oligosaccharides. In vertebrates, ganglioside carb comp. determines blood groups. In gran-neg bacteria, lipopolysaccharides cover the peptidoglycan layer.
Whats the difference between syndecans and glypicans?
Syndecans are proteins that have a single transmembrane domain. Glypicans are proteins that are anchored to a lipid membrane.
Describe the Fehling's and Tollen's test?
Aldehyde can reduce Cu2+ to Cu+ (Fehlings test)
Aldehyde can reduce Ag+ to Ag0 (tollens test)