OChem - Biochemistry

krabi's version from 2015-06-08 11:51

Section 1

Question Answer
What are two hexoses? Fructose & glucose
What is the difference between fructose and glucose? Glucose = aldehyde & Fructose = ketone.
What is an Aldose?aldose is a monosaccharide (a simple sugar) that contains only one aldehyde (-CH=O) group per molecule. eg. Glucose.
What is a Carbohydrate?The chemical formula takes the form Cn(H2O)n
What is a Ketose?A ketose is a monosaccharide containing one ketone group per molecule.
Can Ketoses can isomerize?Ketoses can isomerize into an aldose when the carbonyl group is located at the end of the molecule.
What is an Aldehyde?aldehyde group, here shown as CH=O, is also often written as CHO
Compare aldose and ketonesSo, for a carbohydrate to be an aldose it needs an aldehyde group. And to be a ketose it needs a ketone group.

Section 2

Question Answer
What do the Carbons do in Carbohydrates? Carbons are chiral. Dā‡’ OH is on the Right; or L with the OH on LEFT.
How do Carbs form rings? The OH group on chiral carbon (farthest from the carbonyl); OH does Nuc attack on the carbonyl. Thus, there is Nuc Addn to aldehyde/ketone ā‡’ hemiacetal ring is formed.
What is the anomeric carbon? The only carbon attached to 2 oxygens; OH points either up or down (O-C-O)
What is a furanose?5 member ring
What is Pyranose? 6 membered ring
What is the difference between a reducing and non-reducing sugar? RIG: ends is OSE Non-Reducing: Ends in OSIDE
What is a Sugar that is an Acetal? A glycoside An acetal, but NOT a hemiacetal
What is an Aglycone? Group that attaches to an anomeric carbon

Section 3

Question Answer
What is an Tollens Reagent? A basic reagent that detects aldehydes. Promotes enediol reagent rearrangements of ketoses.
What can Acetals be used as? Blocking groups (as they do not react with Reducing Agents).
Why can Tollens not react w/glycoside? Because glycosides are close chains which do not reduce.
What is a bond between sugars? Glycosidic linkage
How do sugars actually bond with each other? The anomeric carbon of a sugar can react w/any OH group of another sugar. Only 3 ways they can bond: 1,4; 1,6; 1,1.
When can a Disaccharide react w/Tollens? If there is a single anomeric carbon (not involved in a glycosidic linkage) then it is free to react.
How can you break a Glycosidic linkage?Through hydrolysis.
What is Sucrose? 1,1 glycosidic linkage Glucose + Fructose ā‡’ GF sugar
What is Maltose? Glucose + Glucose Alpha 1, 4 glycosidic linkage
What is Lactose? Galactose + Glucose Beta 1,4 glycosidic linkage -- Milky Way =>Galaxy candy bar

Section 4

Question Answer
What is Cellulose? Cannot digest Beta 1,4 Galactoside linkage Galactose+Glucose
What is Amylose? Alpha 1, 4 glycosidic linkage (chain of glucose molecules) Amy is 14, wearing a sugar necklace and the alpha dog of her clique.
What is Amylopectin? Alpha 1, 4 glycosidic linkage w/branches made of alpha glycosidic 1, 6

Section 5

Question Answer
What are 4 techniques to separate different solutions? Chromatography, distillation, crystillation and extraction.
What are the 3 kinds of Spectroscopy? NMR, infrared spectrscopy, and UV spectroscopy.
What is NMR? The stronger the magnetic field, the greater the difference between these energy states. Detect the energy absorption of a nucleus in resonance.
Ether:Corn Flakes are made by Kellogg's. A rooster or cock (C-O-C) is the cornflake mascot.
Aldehyde: Aldehyde: This sounds like "Adelaide," the Australian city. Australia is at the end of the Asian islands, and aldehydes are at the end of the hydrocarbon chain. The "Y" indicates a C=O double bond.
Ketone:Ketone: Imagine the diagonal strokes of "K" going to the O -- forming the C=O double bond.
Carboxylic Acid: Carboxylic Acid: "Box" stands for boxed wine or C-O-H, alcohol. The "Y" indicates a C=O double bond.
EsterEster: Ester the Goriila eats Coconut Coco. So think of O=C-O-C.
Amide: Amine with a "D" -- D is for for double.

Section 6