Term
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Definition
| a direct link between solar energy and the chemical bond energy of living organisms |
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Term
| How are carbohydrates formed? |
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Definition
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Term
| What is the ratio of carbon, hydrogen, and oxygen in most carbohydrates? |
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Definition
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Term
| What are the 4 functions of carbohydrates? |
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Definition
1. source of energy
2. structural roles
3. communication
-intermediates of many metabolic pathways
4. components/precursors of many other biomolecules |
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Term
| How are carbohydrates classified? |
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Definition
| according to the number of simple sugar units they contain |
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Term
| What are glycoconjugates? |
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Definition
| protein and lipid molecules with covalently linked carbohydrate groups |
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Term
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Definition
| monosaccharides with an aldehyde functional group |
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Term
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Definition
| monosaccharides with a ketone functional group |
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Term
| What are the simplest aldose and ketoses? |
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Definition
| glyceraldehyde and dihydroxyacetone |
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Term
| How are sugars classified? |
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Definition
| according to the number of carbon atoms they contain |
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Term
| What are the 2 most abundant monosaccharides found in living cells? |
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Definition
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Term
| What is glucose also referred to as? |
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Definition
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Term
| What happens when the number of chiral carbon atoms increases in optically active compounds? |
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Definition
| the number of possible optical isomers also increases |
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Term
| What is van't Hoff's rule? |
|
Definition
A compound with n chiral carbon atoms has a maximum of 2^n possible stereoisomers
-when n is 4, there are 16 stereoisomers |
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Term
| In optical isomers, what is the reference carbon? |
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Definition
| the asymmetric carbon that is most remote from the carbonyl carbon |
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Term
| What configuration are almost all naturally occurring sugars found as? |
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Definition
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Term
| What are the D-configurations derived from? |
|
Definition
aldoses: triose D-glyceraldehyde
ketoses: nonchiral triose dihydroxyacetone |
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Term
| What are diastereoisomers? |
|
Definition
| Stereoisomers that are not enantiomers (mirror-images of eachother) |
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Term
| What kind of relationship do D-ribos and D-arabinose have? |
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Definition
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Term
|
Definition
| Diastereoisomers that differ in the configuration at a single asymmetric carbon atom |
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Term
| What kind of relationship do D-glucose and D-galactose have? |
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Definition
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Term
| are D-mannose and D-galactose epimers? |
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Definition
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Term
| What are hemiacetals/hemiketals? |
|
Definition
the ring formation that occurs in aqueous solution because the functional group reacts reversibly with hydroxyl (alcohol) groups present in the sugar
-these are unstable |
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Term
| what are the most stable hemiacetals/hemiketals? |
|
Definition
| rings containing 5 or 6 atoms |
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Term
| What is the anomeric carbon atom? |
|
Definition
| the carbonyl carbon that becomes a new chiral center when the cyclization occurs |
|
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Term
|
Definition
| the two possible diastereomers that may form during the cyclization reaction |
|
|
Term
| What are the two stereoisomers that can form because the anomeric carbon is chiral? |
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Definition
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|
Term
| What side does the hydroxyl of the alpha and beta anomer appear in fisher projections of the D-configuration? |
|
Definition
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Term
|
Definition
| the ring shape from o-chem with groups pointing up and down |
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Term
| For D sugars, what form is the structure in when the hydroxyl is down? |
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Definition
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Term
| For D sugars, what form is the structure in when the hydroxyl group is up? |
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Definition
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Term
|
Definition
five-membered hemiacetal rings
ex: fructofuranose |
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Term
|
Definition
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|
Term
| What do conformational formulas show? |
|
Definition
the puckered nature of sugar rings
-uses X-ray and bond angle analysis |
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|
Term
| What are space-filling models? |
|
Definition
| these have dimensions that are proportional to the van-der-waals radius of atoms |
|
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Term
|
Definition
when the alpha and beta forms of monosaccharides are readily interconverted when placed in water
-produces an equilibrium of the two in both furanose and pyranose |
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|
Term
| What is glucoses mixture during mutarotation? |
|
Definition
38% alpha pyranose
62% beta pyranose |
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|
Term
| What is fructoses mixture during mutarotation? |
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Definition
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Term
| What kind of reaction can the open chain formed during mutarotation participate in? |
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Definition
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|
Term
| Where does the hydroxyl group on hemiacetal occur? |
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Definition
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|
Term
| What are haworth structures? |
|
Definition
| these more accurately depict bond angle and length in ring structures than the original fisher projections do |
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|
Term
| What is the cyclic form of fructose? |
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Definition
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|
Term
| What is the cyclic form of pyranose? |
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Definition
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|
Term
| What kind of process is glycolysis? |
|
Definition
|
|
Term
| What are the two stages of glycolysis? |
|
Definition
| energy investment and energy producing |
|
|
Term
| What is the glycolytic pathway? |
|
Definition
| D-glucose + 2 ADP + 2 Pi + 2 NAD+ --> 2 pyruvate + 2 ATP + 2 NADH + 2H+ + H20 |
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Term
| What are the 4 things that the rate of the glycolytic pathway in a cell is controlled by? |
|
Definition
1. kinetic properties of hexokinase isoenzzymes
2. the allosteric enzymes
3. hormonal regulation
4. AMPK |
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|
Term
| What are the 3 allosteric enzymes? |
|
Definition
| Hexokinases I, II, and III |
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Term
| What is the net result of glycolysis? |
|
Definition
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