Carbohydrates Flashcards Preview

Biomedical Chemistry > Carbohydrates > Flashcards

Flashcards in Carbohydrates Deck (22):
1

define: carbohydrates

polyhydroxyaldehydes/polyhydroxyketones, or form these compounds upon hydrolysis

2

define: monosaccharides

carbs that cant be hydrolysed to a simpler form.

3

how do you name monosaccs

prefix: meth eth tri tetr pent ..
suffix: ose
aldo/keto prefix potentially

4

whats a fischer projection

cross, doesnt show middle carbons
most oxidised at the top

5

how do you assign D/L config?

OH on penultimate carbon on left -> L
on right -> D

6

haworth projection

the scary thing.

7

define: anomeric carbon

new stereocentre resulting from cyclic hemiacetal formation. (attached to 2 O's!)

8

how are cyclic hemiacetals formed

ketone and OH in carb chain react to form cyclic molecule. makes hemiacetal fg:

RO OH
C
R' H

9

define anomer:

carbs differing in config at anomeric carbon. B-anomer (OH cis to CH2OH) and a-anomer

10

describe mutarotation

change in specific rotation that accompanies the interconversion of a and B anomers in aqueous solution. occurs in EQUILIBRIRUM
-in equilibrium reactions, reaction reverses, aldehyde flips, cyclic hemiacetal made with another amoner

11

why are chair conformations superior to haworth projections?

while pentoses are planar, hexoses are in chair conformation so it more accurately reps it

12

how are cyclic acetals formed from cyclic hemiacetals.

OH on hemiacetal and OH on HC chain react to form water and condensation polymer.

13

significance of cyclic acetals?

can no longer undergo mutaroation

14

maltose?

2 glucose monomers
a-1,4'-glycoside bond
a-4,1'-glycoside bond

15

lactose?

galactose and glucose
b-1,4'-glycoside bond
a-4,1'-glycoside bond

16

sucrose?

fructose + glucose
a-1,2'-glycoside bond
b-2,1'-glycoside bond)

17

how are N-glycoside bonds formed?

see yer book

18

what glucose does all polysacs have

d glucose

19

describe starch

plant energy storage
-amylose: linear glucose chain
-amylopectin: highly branched polymer. a-1,6'-glucoside bonds

20

describe glycogen

same as amylopectin structure.
animal storage

21

describe cellulose

linear polymer of cluse with B-1,4'-glycoside bonds
glucose rotates

22

define: non reducing sugar

when both anomeric carbons are involved in glycoside bond (cant be reductant) ie. sucrose