Isomers and Related Themes

Question 1

Constitutional Isomers

Answer 1

same molecular formula but differ in order of attached atoms

Question 2

Stereoisomers

Answer 2

same molecular formula and attachment, but differ in spacial arrangement of those bonded groups

Question 3

Enantiomers

Answer 3

stereoisomers that mirror images of themselves

Question 4

Diastereoisomers

Answer 4

isomers that are not mirror images

Question 5

Epimers

Answer 5

diastereoisomer that differs at ONE of several asymmetric carbons

example: D-glyceraldehyde and L-glyceraldehyde

Question 6

Anomers

Answer 6

Diastereoisomers that differ at new asymmetric carbon upon ring closure

example: alpha-D-glucose and beta-D-glucose

Question 7

D-glyceraldehyde, alpha D glucose, L-glyceraldehyde, beta D glucose: match the pairs and describe their commonality

Answer 7

D and L glyceraldehyde are epimers (differ around a single asymmetric carbon and the other two are anomers, they differ around a single carbon AFTER cyclization occurs

Question 8

Aldose Ketose pairs

Answer 8

glucose + fructose, glyceraldehyde and dihydroxyacetone

constitutional isomers (aka aldose-ketose pairs)

Question 9

AGEs

Answer 9

Advanced Glycation End products or Advanced Glycosylation End products

Question 10

AGE formation

Answer 10

a) fluorescence b) protein cross linking c) loss of protein functions d) recognition by receptor for AGEs

Question 11

Maillard Reaction Initiation, Propagation, Advanced Stage

Answer 11

Initiation: Protein + sugar
Propagation: Schiff base
Advanced stage: fluorescence, protein cross linking, loss of protein function, recognition by receptor for AGEs

Question 12

Two nasty byproducts of glucose oxidation

Answer 12

3-deoxyglucose (3DG) and methylglyoxyl (MG)

Question 13

MG + 3DG —-> products (?) name of process? proof in the body?

Answer 13

Enzymes break down MG and 3DG and react with them, so basically the products of glucose oxidation react with proteins and modifies them negatively

glycation

they can react with Hg to make HgA1C

Question 14

Hg A1C test

Answer 14

Test for diabetes: hemoglobin A1C is high when their glucose is high, it means the glucose has been reacting with hemoglobin

Question 15

Glycated tissues

Answer 15

cross linked, they don’t get disposed of and become stiff

Question 16

Hyperglycemia

Answer 16

leads to protein glycation and potential loss of protein function in a variety of tissues (amputations for instance)

Question 17

LDL

Answer 17

Hangs around a long time and gets oxidized. LDL just gets glycated

Question 18

AGEs manifest from

Answer 18

glycation of proteins by carbonyl possessing compounds and aging tissues

Question 19

AGEs cause

Answer 19

inflammation because macrophages react with them and cause inflammation cascade

Question 20

monosaccharides

Answer 20

“polyhydroxy ketone or aldehyde”

“simple carb”

contain a lot of aldehydes and carbonyls

Question 21

Disaccharides

Answer 21

table sugar

Question 22

Polysaccharides

Answer 22

starch and glycogen

Question 23

Hexose and “-ose”

Answer 23

Sugar with six carbons, ose means sugar: aldose

Question 24

Pentose

Answer 24

5 carbon sugar:

Question 25

Tetrose

Answer 25

4 carbon sugar

Question 26

Triose

Answer 26

3 carbon

Question 27

a sugar with an aldehyde is called an

Answer 27

aldose

Question 28

a sugar with a ketone is called a

Answer 28

ketose

Question 29

alpha vs beta configuration

Answer 29

(b UP) not (A downer)

Question 30

epimeric pairs include

Answer 30

d-glucose and d-mannose and d-glucose and d-mannose

Question 31

d-mannose and d-mannose are NOT

Answer 31

epimers

Question 32

99.9% of glucose in the blood is

Answer 32

cyclized; .1 percent is in the straight chain form

Question 33

cyclization

Answer 33

results in a configuration change around the enomeric carbon

Question 34

2 prime applies to what

Answer 34

the epimeric carbon around which glucose and mannose, differ in hydroxyl arrangement

Question 35

4 prime applies to what

Answer 35

the epimeric carbon around which glucose and galactose differ in hydroxyl arrangement

Question 36

how does fructose relate to glucose?

Answer 36

aldose-ketose pair

Question 37

Pyranose vs Furanose

Answer 37

Pyranose is a 5 carbon cyclic with oxygen at one point: the ring glucose makes after forming the hemiactetal: produces alpha and beta rings. Pryanose is another name for glucose. Pyran refers to a six membered ring strcuture

Furanose is a 5 (4 carbons plus one oxygen) membered cyclic ring that forms when ribose or fructose cyclizes with itself

Question 38

Fehling’s Reagent

Answer 38

Clinical test for glucose in the urine. Glucose reduces copper from Cu2+ to Cu+

Glucose + Cu2+—> Cu2O + glucose

ANY reducing sugar can give a Fehling’s reagent, so it isn’t a conclusive test.

Question 39

What does Fehling’s reagent test for?

Answer 39

a free anomeric carbon during the straight chain form of a reducing sugar: it doesn’t necessarily have to be glucose