Carbs & Glucose

Question 1

what are carbohydrates?

Answer 1

Polyhydroxylated aldehydes or ketones with three or more carbon atoms, or substances which can be hydrolysed to form these.

Question 2

monosaccharides

Answer 2

Defined functionally as carbohydrates which cannot be hydrolysed (broken down) further into simpler compounds.

Question 3

two broad types of monosaccharides:

Answer 3

Aldoses
Ketoses

Question 4

Aldoses

Answer 4

contain an aldehyde group (i.e. terminal CHO)

Question 5

Ketoses

Answer 5

contains a keto group (i.e. an internal C=O)

Question 6

monosaccharide structure

Answer 6

Can be chemically identical but have a 3D arrangement of atoms.

Question 7

Enantiomers

Answer 7

Mirror image forms

Have identical chemical and physical properties

Each shares the same molecular formula but has a different structure.

Two forms cannot be superimposed on one another.

Question 8

Chiral carbon

Answer 8

C5 = reference carbon

Question 9

in solutions glucose can …

Answer 9

form ring structures

Aldehyde groups can react with hydroxyl groups, form something called a hemiacetal.

Question 10

glucose ‘eats its tail’ to form ….

Answer 10

an intramolecular hemiacetal

Question 11

x-orientation

Answer 11

OH group on the anomeric carbon is cis to the CH2OH

Question 12

ss-orientation

Answer 12

OH group on the anomeric carbon is trans to the CH2OH

Question 13

Fates of Glucose

Answer 13

> breakdown via glycolysis.
Modify other molecules.
Storage: Glycogen, starch.

Question 14

Glycolysis

Answer 14

splitting of sugar

Question 15

universal pathway for glucose breakdown

Answer 15

some cells very dependent on it ( brain, RBC, sperm)

Question 16

anaerobic

Answer 16

doesn’t need oxygen to work

Question 17

glycolysis at a glance

Answer 17

Phosphorylate glucose twice -> split it down the middle -> oxidase the two triose-phosphates -> form high-energy phosphate bonds -> cleave these and make ATP./.,m

Question 18

x-glycosidic bond

Answer 18

links 2 sugars via the bond below the plane of the ring, opposite to the configuration at C5.

Question 19

ss-glycosidic bond

Answer 19

the configuration of the group at C5 are the same.

Question 20

polysaccharides structure

Answer 20

branched
unbranched

Question 21

polysaccharide composition

Answer 21

homopolysaccs
heterpolysaccs

Question 22

homopolysaccs

Answer 22

monomers all identical

Question 23

heterpolysaccs

Answer 23

monomers different

Question 24

structure of glycogen

Answer 24

essentially a ball of glucose

Question 25

Glycogenin

Answer 25

acts as a seed to start the construction of glycogen

Question 26

CHO=

Answer 26

polyhydroxylated aldehydes and ketones

Question 27

(CH2O)n <——-n =

Answer 27

n is at least 3