Carbohydrates Flashcards
What is the general formula for carbohydrates?
What are the two main classes of monosaccharides?
Aldoses: aldehyde containing saccharide.
Ketose : ketone containing saccharide.
What are 3-carbon sugars called? What about 4?
3- Triose
4- Tetrose
Define Enantiomers
Non-superimposable mirror images.
Is a mirror image, but can’t make them identical when overlapping.
What is a fisher projection telling you?
Horizontal bonds are above the plane while vertical lines are below the plane.
When do we classify molecules as D or L? And how?
When multiple chiral centers are present.
The carbon furthest from the carbonyl group determines D vs L.
When sugar in proper confirmation: carbonyl at top, to farthest chiral carbon at bottom. Left OH on bottom chiral carbon equals L, Right OH equals D.
D sugars are more common than L and biology .
Define diastereomer. What’s the equation related to them?
Non-enantiomeric stereoisomers.
Define epimer
Stereoisomers that differ at a single chiral center.
Understand the slide.
Memorize all the names, especially those in pink boxes!
Test: how many diasteromers are apart of Aldohexose? What about Ketohexoses?
What is the keto tataunomer called of Xylose?
Draw out the reaction for hemiacetal formation. What changes for hemiketal formation?
What name to we tack on to the end of 5 member ring sugars? What about 6 member ring sugars?
5- furan
6- pyran
Define anomeric carbon.
The carbon that is usually not chiral and has the carbonyl group, but in cyclic form has chirality.
What makes a anomeric carbon alpha vs beta? What state of sugar is most common in the body? (For D sugars specifically)
For this class remember it this way!
Define what a glycosidic bond is.
When an anomeric carbon reacts with an alcohol, the new C-O bond formed is called a glycosidic bond.
Note: once this bond is formed, the molecules locked in it can no longer re-transition into the straight chain.
Summary nomenclature test:
What is the energy required to make galactose and glucose into lactose?
What is the important take away of this mechanism?
Storing chemical energy in activated intermediates help drive unfavorable reactions.
Define what maltose is.
What is the reducing vs non-reducing end? And what makes them different?
How would we write the glycosidic bond?
What’s the full name?
And the abbreviated name?
Your mouth can break down other parts of starch but maltose can only be broken down in intestine.
What is this disaccharide called?
What makes this molecule?
What’s the full name?
What side is the reducing side and the nonreducing side?
What makes saccharide polymerization so different from Nucleic acids and proteins? (3 things!)
What are the two major functions of saccharide polymerization?
What polysaccharide is this? Hint: most abundant single polymer on earth.
What is able to digest it? What are the requirements to digest it?
What is the macro structure of lots of it polymerized?
How similar is it to amylose?
Cellulose!
We can’t digest it cause we don’t have cellulases(enzyme to break down the beta linkage D: )
Very strong macrostructure! That’s why it’s used for plant walls.
What is this polysaccharide called? Common name mainly but if you can scientific name.
What is the only difference from cellulose? Where is this found?
Shell of Alaskan king crab!
That one N-Acetylated carbon 2 group makes the shell different from wood.
What polysaccharide is this? What structure does it make in long unbranched chains?
What makes amylopectin different from amylose?
Amylopectin can be broken down way faster because it has multiple nonreducing ends that enzymes can breakdown at once.
Note: they can get huge! And since it can make two different types of bonds it can be branched.
Define what Glycogen is.
Almost identical to Amylopectin but it has way more branches. Ie. Even faster to break down and synthesize.
Summary:
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