L.12 Carbohydrates Flashcards Preview

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Flashcards in L.12 Carbohydrates Deck (19)
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1

How are carbohydrates organized? 

by their number of carbons and functional groups

2

Three common names for carbohydrates

  • Glucose
  • Fructose 
  • Galactose

3

What are 3 carbon sugars? Four? 

Trioses

Tetroses

4

Sugars with Aldehydes and Sugars with

Ketones as their most oxidized group are named what? 

Aldoses

Ketoses 

5

Nomenclature of sugars

Nomemclature of all sugar is based on the

D- and L- forms of glyceraldehyde. 

Sugars with the highest-numbered chiral carbon with the -OH group on the RIGHT (fisher projection) are D sugars/

on left, L Sugars. 

D & L = Enantiomeres

 

Glyceraldehyde is a triose monosaccharide with chemical formula C3H6O3. It is the simplest of all common aldoses. It is a sweet, colourless crystalline solid that is an intermediate compound in carbohydrate metabolism.

6

What are diastereomers 

Non-superimposable configurations of molecules with similar connectivity. They differ at at least one - but - not all chiral carbons. These include 

Epimers; differ at one chiral carbon

Anomers; differ at the anomeric carbon

7

Cyclization describes the ring formation of carbohydrates, when these form, the anomeric carbon can take either an alpha or beta conformation. 

The anomeric carbon is the new chiral center formed in the ring closure,

it was the carbon containing the carbonyl. 

 

Alpha-anomers have the -OH on the anomeric

carbon ______ to the free -CH2OH group.

;

beta- anomers?

 

Alpha TRANS

Beta CIS

8

Hawthorn Projections provide?

Provide a good way to represent 3D structures

9

Cyclic compounds can undergo MUTAROTATION, which is what?

Shifting from one anomeric for to another with the straight chain form as an intermediate.

10

What are Monosaccharides? 

What 3 main reactions can they undergo?

single carbohydrate units, with glucose as the most commonly observed monomer.

 

They can undergo 3 main reactions.

  1. oxidation-reduction
  2. esterification
  3. glycoside formation

11

Aldoses can be oxidized and reduced to produce what? 

Oxidized; Aldonic Acids

Reduced; Alditols

12

What kind of sugars can be reacted with Tollen' or Benedict's reagents to detect those sugars? 

Sugars that can oxidized are reducing agents (reducing sugars) 

13

Sugars with an -H replacing an -OH are termed? 

DEOXY Sugars

14

Sugars that react with carboxylic acids and their derivatives form what? 

ESTERS in an esterification reaction

15

What is phosphorylation? 

Phosphate ester is formed by transfering a phospahete group from ATP onto a sugar

 

16

Glycoside formation

is the basis for building complex carbohydrates and requires the anomeric carbon to link to another sugar

17

What are dissacharides?

form as a result of glycosidic bonding berween two monosacharide subunits;

 

polyssacharides form by reapeated monossacharide or polyssacharide glycosidic bonding

18

What are the 3 common disaccharides? 

1. Sucrose glucose-alpha-1,2-fructose

2. Lactose galactose-beta-1,4-glucose

3. Maltose glucose-alpha-1,4-glucose

19

What 3 main roles do polysaccharides play? 

As

Cellulose;

the main source of fiber in the human diet found in plants cell walls for a structural component

 

Starches (amylose and amylopectin);

main energy storage form for plants

 

Glycogen;

main energy storage form for animals