Biological molecules

Question 1

Carbohydrates and fats are made up of

Answer 1

carbon, hydrogen and oxygen.

Question 2

Proteins are made up of

Answer 2

carbon, hydrogen, oxygen and nitrogen

Question 3

Starch, glycogen, and cellulose are made from

Answer 3

glucose

Question 4

Proteins are made from

Answer 4

amino acids

Question 5

Fats and oils are made from

Answer 5

3 fatty acids and 1 glycerol.

Question 6

starch test

Answer 6

take few drops of sample on a white tile, add a drop of iodine solution. observe the color change from orange- brown to blue black confirming the presence of starch

Question 7

protein test

Answer 7

take a knwon volume of sample, add few drops of buirette solution. observe the color change
a) blue to lilac ( traces )
b) blue to purple ( low concentration )
c) blue to violet ( high concentration)

Question 8

vitamin C test

Answer 8

add 1cm³ of DCPIP solution in a test tube, add small amount of sample. observe the color of blue color disappearing

Question 9

Fat test (lipids)

Answer 9

take sample in a test tube, add ethanol until you get a clear solution. add few drops of distilled water. if the solution turns cloudy or milky confirms the presence of fats

Question 10

reducing sugars ( glucose ) test

Answer 10

take a known volume of sample, add equal volume of benedicts solution, heat using a thermostatically controlled digital water bath at 80°C. observe the color change
a) blue to green ( traces )
b) blue to yellow ( low concentration)
c) blue to orange ( mild concentration)
d) blue to brick red ( high concentration)

Question 11

Structure of DNA:

Answer 11

Two strands coiled together to form a double helix
Each strand contains chemicals called bases
Bonds between pairs of bases hold the strands together
The bases always pair up in the same way: A with T, and C with G