Carbohydrates Flashcards Preview

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Flashcards in Carbohydrates Deck (22)
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1
Q

define: carbohydrates

A

polyhydroxyaldehydes/polyhydroxyketones, or form these compounds upon hydrolysis

2
Q

define: monosaccharides

A

carbs that cant be hydrolysed to a simpler form.

3
Q

how do you name monosaccs

A

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

4
Q

whats a fischer projection

A

cross, doesnt show middle carbons

most oxidised at the top

5
Q

how do you assign D/L config?

A

OH on penultimate carbon on left -> L

on right -> D

6
Q

haworth projection

A

the scary thing.

7
Q

define: anomeric carbon

A

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

8
Q

how are cyclic hemiacetals formed

A

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

RO OH
C
R’ H

9
Q

define anomer:

A

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

10
Q

describe mutarotation

A

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
Q

why are chair conformations superior to haworth projections?

A

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

12
Q

how are cyclic acetals formed from cyclic hemiacetals.

A

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

13
Q

significance of cyclic acetals?

A

can no longer undergo mutaroation

14
Q

maltose?

A

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

15
Q

lactose?

A

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

16
Q

sucrose?

A

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

17
Q

how are N-glycoside bonds formed?

A

see yer book

18
Q

what glucose does all polysacs have

A

d glucose

19
Q

describe starch

A

plant energy storage

  • amylose: linear glucose chain
  • amylopectin: highly branched polymer. a-1,6’-glucoside bonds
20
Q

describe glycogen

A

same as amylopectin structure.

animal storage

21
Q

describe cellulose

A

linear polymer of cluse with B-1,4’-glycoside bonds

glucose rotates

22
Q

define: non reducing sugar

A

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