Chap 21 Flashcards
1
Q
structure of carbohydrates in general.
A
- Ketoses – ch2oh-co-R
- Aldoses – coh-R
- hexoses (6) pentoses (5)
2
Q
optical rotation
A
- Polarize light in a different plane. D bends light right. L bends light left
3
Q
Stereoisomers formula
A
- Number of Chiral centers^2
4
Q
Fisher project
A
- Wedges come out and dashed lines go in
5
Q
difference between D- and L- sugars, and which one predominates in nature.
A
- In D (most common), chiral center farthest from the OH group faces right, in L it faces left.
6
Q
able to find the anomeric carbon
A
- C that is bonded to 2 O molecules. C1 in aldoses, C2 in ketoses
- Anomers – alpha = OH on bottom. Beta = OH on top
7
Q
to predict if a sugar will undergo mutarotation, or will be a reducing sugar.
A
- When the sugar reaches equilibrium between open-chain, close-chain forms (alpha and beta) in a solution. This changes the optical rotation.
- Reducing sugars can open, if it has an OH on the anomeric carbon
o All monosaccharides, Lactose (glucose-galactose) and Maltose (glucose-glucose). Not sucrose (fructose-glucose) because O bonds with both anomeric carbons, so they can’t open.
8
Q
Can ketoses be reducing sugars??
A
- Yes, it can be converted to an aldose, then reduced by adding an O to the acyl group
9
Q
Sucrose, Lactose, Maltose
A
sucrose=glucose and fructose, lactose= galactose and glucose maltose= glucose and glucose
10
Q
Why is cartilage so “springy”?
A
- Polysaccharides hold 2x their mass in water, which acts as a shock absorber and lubricant. When pressed together, the charges repel one another as well.
11
Q
blood-type antigens and what they are made of.
A
- All have N acetyl glucosamine – D glucose – L fructose
o Type O – no extra side chain
o Type A – extra N-acetyl D-galactosamine
o Type B – Extra D-galactose
12
Q
celllulose and chitin
A
- Cellulose - All glucose polymer, alternating alpha and beta linkages.
o In plants - Chitin – Same as cellulose with an amino acid and acetyl group.
o Exoskeletons
13
Q
starch and glycogen bond numbers
A
- Glycogen – protein core (glycogenin), branch every 11 +/- 3 glucose.
- Starch – Amylopectin core, branched form of starch. Branch every 27 +/- 3 glucose.