BIO 1404 Practical Questions and Answers
Benedict's Test green solution Correct Ans-indicates a small amount of reducing sugars
Benedict's Test reddish orange solution Correct Ans-indicates an abundance of reducing
sugars
Non-reducing sugars such as sucrose Correct Ans-produce no change in color
Iodine Test Correct Ans-distinguishes starch from monosaccharides, disaccharides, and
other polysaccharides
basis for iodine test Correct Ans-starch is a coiled polymer of glucose
positive test for iodine test (starch) Correct Ans-a bluish-black color
negative test for iodine test (starch) Correct Ans-yellowish-brown color
, BIO 1404 Practical Questions and Answers
intermediate color reaction for iodine test Correct Ans-Glycogen, a common
polysaccharide in animals, has a slightly different structure than does starch
negative- tube with distilled water
positive- glucose & fructose solution Correct Ans-Which one of the solutions is the positive
control, and which one of the solutions is the negative control for the Benedict's reaction?
potato juice because the benedict reaction was blue in onion juice indicating no reducing
sugar Correct Ans-Which contains more reducing sugars, potato juice or onion juice? How
do you know?
negative control- tube with distilled water
positive control- tube with starch & potato juice Correct Ans-Which one of the solutions is
the positive control, and which one of the solutions is the negative control for the Iodine
reaction?
potato juice since there is more starch present Correct Ans-Which colors more intensely
for the Iodine Reaction, onion juice or potato juice? Why?
Benedict's Test green solution Correct Ans-indicates a small amount of reducing sugars
Benedict's Test reddish orange solution Correct Ans-indicates an abundance of reducing
sugars
Non-reducing sugars such as sucrose Correct Ans-produce no change in color
Iodine Test Correct Ans-distinguishes starch from monosaccharides, disaccharides, and
other polysaccharides
basis for iodine test Correct Ans-starch is a coiled polymer of glucose
positive test for iodine test (starch) Correct Ans-a bluish-black color
negative test for iodine test (starch) Correct Ans-yellowish-brown color
, BIO 1404 Practical Questions and Answers
intermediate color reaction for iodine test Correct Ans-Glycogen, a common
polysaccharide in animals, has a slightly different structure than does starch
negative- tube with distilled water
positive- glucose & fructose solution Correct Ans-Which one of the solutions is the positive
control, and which one of the solutions is the negative control for the Benedict's reaction?
potato juice because the benedict reaction was blue in onion juice indicating no reducing
sugar Correct Ans-Which contains more reducing sugars, potato juice or onion juice? How
do you know?
negative control- tube with distilled water
positive control- tube with starch & potato juice Correct Ans-Which one of the solutions is
the positive control, and which one of the solutions is the negative control for the Iodine
reaction?
potato juice since there is more starch present Correct Ans-Which colors more intensely
for the Iodine Reaction, onion juice or potato juice? Why?
