Carbs Lab

Question 1

simplest ketose, a ketotriose

Answer 1

dihydroxyacetone

Question 2

simplest aldose where D represents the right handed configuration of sugar

Answer 2

d-glyceraldehyde

Question 3

dihydroxyacetone is chiral/achiral

Answer 3

achiral

Question 4

useful qualitative test for the presence of starch

Answer 4

iodine test

Question 5

strong base that can be used to treat cellulose and then exposing it to carbon disulfide fumes to yield
films and threads

Answer 5

NaOH

Question 6

Four qualitative tests used in carbohydrates

Answer 6

Barfoed’s
Seliwanoff’s
Benedict’s
Lugol’s

Question 7

utilizes cupric acetate in dilute acetic acid solution

Answer 7

Barfoed’s test

Question 8

Barfoed’s test reagent

Answer 8

Cupric acetate in dilute acetic acid solution

Question 9

React with monosaccharides in general which results to formation of sugar acid and brick-red or rust-colored copper oxide precipitate

Answer 9

Barfoed’s test

Question 10

Barfoed’s test positive shows

Answer 10

red precipitate

Question 11

red precipitate in barfoed’s test tells us that

Answer 11

monosaccharide is present

Question 12

uses resorcinol in dilute hydrochloric acid solution

Answer 12

Seliwanoff’s test

Question 13

Seliwanoff’s test reagent

Answer 13

resorcinol in dilute hydrochloric acid solution

Question 14

Reacts with ketoses to form cherry red dye or conjugate upon heating

Answer 14

seliwanoff reagent

Question 15

seliwanoff’s test show positive when

Answer 15

cherry red dye or conjugate appears

Question 16

involves the addition cupric sulfate in sodium carbonate and sodium citrate solution to the sample

Answer 16

Benedict’s test

Question 17

Test for reducing sugars, whether monosaccharides or disaccharides, react with this reagent as manifested in the formation of sugar acid and brick-red or rust-colored copper oxide precipitate

Answer 17

Benedict’s test

Question 18

Benedict’s test will be positive in the presence of r

Answer 18

reducing sugars

Question 19

benedict’s test reagent

Answer 19

cupric sulfate in sodium carbonate and sodium citrate solutionbe

Question 20

benedict’s test will turn positive in what color

Answer 20

red (large amount)/orange (moderate)

Question 21

uses iodine in potassium iodide to specifically detect the presence of starch or glycogen

Answer 21

Lugol’s test

Question 22

Lugol’s test reagent

Answer 22

iodine in potassium iodide

Question 23

Lugol’s test is used to detech the presence of whatr

Answer 23

starch/glycogen

Question 24

Evident in formation of blue-black dye complex for starch and blue-brown dye for glycogen

Answer 24

Lugol’s test

Question 25

color of benedict when 0.5% of reducing sugar exist

Answer 25

green

Question 26

color of benedict when 1% of reducing sugar exist

Answer 26

yellow

Question 27

color of benedict when 1.5% of reducing sugar exist

Answer 27

orange

Question 28

color of benedict when 2% of reducing sugar exist

Answer 28

red