Carbohydrates

Question 1

asymmetric carbons

Answer 1

When carbon has 4 different molecules attached to it (ex. Carbon 2 in glucose)

Question 2

Chiral molecule

Answer 2

Presence of an asymmetric carbon

Question 3

Structural isomers

Answer 3

same units, but structurally different

Question 4

Stereoisomer

Answer 4

mirror image, same units

Question 5

D, L

Answer 5

Dextro- right, Levo- left

glucose is dextro, sugars used in biological systems are always D

Question 6

Glucose

Answer 6

most important sugar, hexose, C6H12O6, positioning of OH matters

Question 7

Enzyme

Answer 7

biological catalyst, which speeds up chemical reaction, does not change equilibrium constant, and is unaffected by the reaction itself

Question 8

dehydration/condensation rxn

Answer 8

reaction used to bind 2 monomers together, ex. glucose + glucose = maltose, H2O is removed

Question 9

hydrolysis

Answer 9

addition of H2O- use water to split (happens in digestion)

Question 10

saccharides

Answer 10

carbohydrates, sugars

Question 11

Alpha and beta forms of sugars

Answer 11

When circularization (ring structure) occurs- indicated on carbon 1 which now has OH group on it
OH either sticks down or up
If down–> called an alpha hydroxyl
if up–> beta hydroxyl

Question 12

Starch, purpose, linkage

Answer 12

polysaccharide- chain of alpha glucose subunits
Has alpha 1-4 linkages
Called amylose in plants
purpose- energy storage

Question 13

Cellulose, linkage

Answer 13

polysaccharide with glucose, beta 1-4 linkages
Undigested fiber in our diet- we cannot break down beta linkage
Used for structure in plants- cell walls
ex. Cows eat a lot of grass- don’t make enzyme to break down cellulose, but their gut has microorganisms that do make those enzymes
purpose- structural for plants

Question 14

Glycogen/glycogen storage diseases

Answer 14

stored glucose to control sugar in blood, make more or less when needed
in liver and muscles
as people age, tend to use less
ex. running- break down glycogen and metabolize sugars
ex. glycogen storage diseases- people missing enzymes involved in adding/removing glycogen, so blood sugar cannot be controlled

Question 15

Amylose, linkage

Answer 15

Unbranched starch, 20% of starch in potato is amylose
simplest structure made up of lots of alpha-glucose
alpha 1-4 linkage

Question 16

Disaccharides

Answer 16

Two sugars stuck together, transport sugars in plants

Question 17

lactose intolerance

Answer 17

when breastfeeding has ended, people lose the enzyme that can digest lactose aka lactose intolerance

Question 18

maltose

Answer 18

Glucose + Glucose alpha 1-4 linkage

Question 19

lactose

Answer 19

glucose + Galactose, beta 1-4 linkage

Question 20

sucrose

Answer 20

Fructose + Glucose , alpha 1-4 linkage

Question 21

amylopectin, linkage

Answer 21

80% of starch in potato
combined branched amylose
alpha 1-4 and alpha 1-6 linkage at branch point

Question 22

amylase

Answer 22

enzyme that breaks down amylose
present in the salivary glands
cuts off 2 glucose links (maltose) to break down
cannot digest at branch point–> rest of amylose is digested in the pancreas

Question 23

Peptidoglycan, linkage

Answer 23

polysaccharide, Long strand of beta 1-4 linkages (similar to cellulose) but with amino groups
ex. used to build bacterial cell walls

Question 24

chitin, linkage

Answer 24

similar to glucose structure, substance that you find in the cell walls of fungi
ex. exoskeletons, crustaceans
undigestible because of beta 1-4 linkages