Carbohydrates

Question 1

Carbohydrates

Answer 1

Basic chemical structure is CnH2nOn. Also called saccharides. Most abundant organic molecules in nature.

Question 2

Monosaccharides

Answer 2

Simple sugars, can be classified by number of carbon atoms. One single sugar unit.

Question 3

Enantiomer

Answer 3

Molecules which are mirror images of each other.

Question 4

Chiral center

Answer 4

Atom at which individual, unique groups are attached.

Question 5

D-Glucose

Answer 5

Biologically functional form of glucose. Most enzymes are specific only to the D form.

Question 6

L-GLucose

Answer 6

Enantiomer of D-Glucose. No biologically active.

Question 7

Chiral molecules

Answer 7

Can rotate plane polarized light, called optical activity.
D molecules are dextrorotary, they rotate clockwise.
L molecules are Levorotary, they rotate counterclockwise.

Question 8

Racemases

Answer 8

Enzymes that can convert amino acids between D and L isomers. All AA in mammals are L configuration.

Question 9

Isomers

Answer 9

Molecules that have the same atomic composition but different arrangements.

Question 10

D-Fructose

Answer 10

Isomer of D-glucose with a ketone at C2 position.

Question 11

Epimers

Answer 11

Stereoisomers that differ in the position of the hydroxyl group at only one chiral carbon.

Question 12

D-Galactose

Answer 12

Epimer of D-glucose with rotation of hydroxyl at C4.

Question 13

D-Mannose

Answer 13

Epimer of D-glucose with rotation of hydroxyl at C2.

Question 14

epimerases

Answer 14

Enzyme that converts epimer pairs.

Question 15

Pyran Ring

Answer 15

6 membered carbon ring, one member is oxygen.

Question 16

Furan ring

Answer 16

5 membered carbon ring, one member is oxygen.

Question 17

Hemiacetal bonnd

Answer 17

Bond formed between oxygen and carbon.

Question 18

alpha D-glucose

Answer 18

C1 hydroxyl group oriented down, less common

Question 19

Beta D-glucose

Answer 19

C1 hydroxyl group oriented up, more common

Question 20

Glycosidic Linkages

Answer 20

Bonds that link sugars. Formed between hydroxyl groups on adjacent rings.

Question 21

Alpha (1,4) bond

Answer 21

Bond between alpha configuration on C1 and C4 hydroxl of next molecule.

Question 22

Alpha (1,6) bonds

Answer 22

Alpha conformation on C1 bonds to hydroxyl on C6 of the second molecule.

Question 23

Maltose

Answer 23

Disaccharide composed of two glucose molecules in an alpha 1,4 conformation.

Question 24

Isomaltose

Answer 24

Disaccharide of two glucose molecules in alpha 1,6 formation.

Question 25

Amylose

Answer 25

Polysaccharide linear polymer of alpha D glucose Linked in alpha 1,4 bonds.

Question 26

Amylopectin

Answer 26

linear polymer of glucose residues linked together by alpha 1,4 bonds, but every 24-30 residues there is an alpha 1,6 bond, starting a new linear chain. The branch point has a glucose on C1, C4, and C6

Question 27

Glycogen

Answer 27

linear polymer of glucose residues linked together by alpha 1,4 bonds, but every 8-12 residues there is an alpha 1,6 bond, starting a new linear chain. The branch point has a glucose on C6, C1 and C4.

Question 28

Cellulose

Answer 28

Linear polymer of glucose all linked by Beta (1,4) bonds. It is non-digestible, and is insoluble dietary fiber. Has no nutritive value. Ruminant animals have bacteria in their guts which can digest it.

Question 29

Lactose

Answer 29

Galactose and Glucose bound by a Beta (1,4) bond.

Question 30

Beta-D-Fructose

Answer 30

Cyclized fructose with the C2 hydroxyl oriented above the ring.

Question 31

Sucrose

Answer 31

Alpha-D-Glucose and Beta-D-Fructose in an alpha, beta (1,2) bond. It is a nonreducing sugar since both rings are locked.