carb test

Question 1

how do ketoes based rings form?

Answer 1

the C5 attacks C2. this is for fructose furanose

Question 2

how do aldose based rings form?

Answer 2

C5 attacks C1 to form a pyranose and C2 to form a ketose

Question 3

what is the most sable sting structure and why?

Answer 3

when in the chair conformation. this is because in this conformation the substituents in the axial plan have the least amount of steric hindrance

Question 4

is ring closure an intra or inter-molecular process?

Answer 4

intramolecletuar. this open form attacks itself

Question 5

what is a hemi ketol? hemi acetol?

Answer 5

the group of molecules that attach to a C to form the anomeric centre
(c)OH,OR,R,R’

Question 6

what are the monom saccharides that we need to know

Answer 6

fructose = hexose and ketol

ribose = pentose

glucose, mannose, galactose

Question 7

what is sucrose made of

Answer 7

glucose and fructose

Question 8

what is maltose made of

Answer 8

2 glucose

Question 9

what is galactose made of

Answer 9

galactose and glucose

Question 10

what is a glycosidic bond

Answer 10

the bond between an anomeric carbon and an alcohol from another molecule

Question 11

what is a reducing sugar

Answer 11

the ability for a monosac to interconvert between the ring and closed ring form as the anomeric carbon is not involved in glycosidic bonds. The aldehyde group interacts with an oxidizing agent to donate protons and break the bond

note that the mon sac does not need to be an adlose for this to occur, due to tautomerization, a mono sac can go back and forth between ketone and an aldose.

Question 12

how can glucose be stored in the body?

Answer 12

either as glycogen or starch (amylose or amylopectin)

Question 13

what enzyme breaks down glycogen and starches

Answer 13

alpha-amylase

Question 14

what is inulin

Answer 14

as energy storage in plant comprised of glucose attaches by B2,1 glycosidic bonds

Question 15

O linked glycosylation

Answer 15

carbs that are attached to a protein via forming a glycosidic bond with the hydroxyl group of a side chain residue

anomeric carbon attaches to Serine or threonine

Question 16

why does glycosylation change the properties of a protein

Answer 16

once attached to another mole, the og carb gains chemical information (diversifies them) and is more likey to be able to participate is a wider variety of functions

Question 17

glycosylated protein vs lectin

Question 18

N linked glycosylastion

Answer 18

carbs that attach to a protein via forming a glycosidic bond with the amino group of a side chain residue. All N linked oligo sacs have a 5 sugar core (3 mannose, 1 six C sugar (commonly mannose) and 2 N-acetylglucoamines)

anomeric carbon attached to terminal Asparginine

Question 19

which enzyme catalyses the linkage of proteins with carbs?

Answer 19

glycosyltransferase. activated sugars (bound to UDP) are bound to the AA residue unit)

Question 20

on which glyco protein are more sugars are able to attach to?

Answer 20

N linked. this is because of the 5 sugar core.

Question 21

what factors dictate the richness of chemistry found in carbs?

Answer 21

1) the number of gly bonds
2)the total number of mono sacs joined together
3)the proportions of anomeric conformations (a vs B)
4)how they attach to proteins

Question 22

what are the three classes of glyco proteins

Answer 22

1) glycoproteins
2) proteoglycans
3) mucins

Question 23

what are glycoproteins

Answer 23

a carb and prot unit of which proteins constitute the majority of the mass of the mole

Question 24

what are proteoglycans

Answer 24

a carb and prot unit of which carbs make up the majority of the mass

the carb that dominates here is a glycosaminoglycan

these models function structurally in tissues and as a lubricant. overall these moles have a negative charge which is able to induce the movement of water into or out of tissues based on pressure (like in the heal)

Question 25

what are mucins

Answer 25

a carb and prot unit of which carbs make up the majority of the mass

the carb that dominates is a N-acetylgalactosamine.

these models function as a lubricant and have a defining VTR backbone. along the backbone ser and Thr attach to the carbs moles. commonly they will bond to epithelial cells to form a gel and protective barriers

Question 26

what are lectins

Answer 26

proteins that specifically bind to carbs via non covalent interactions. commonly, they will bind glycoproteins to other surfaces.

selectins bind immune system cells to injury sites