Biological Molecules

Question 1

Elements in Molecules

Answer 1

Carbohydrates: C, H, O
Fats & Oils: C, H, O
Proteins: C, H, O, N, (S)

Question 2

Building Large Molecules

Answer 2

Starch, Glycogen, Cellulose: Made from Glucose
Proteins: Made from Amino Acids
Fats & Oils: Made from Fatty Acids and Glycerol

Question 3

Food Tests

Reducing Sugars Test:

Answer 3

Solution: Benedict’s Solution
Heat: 70-80°C
Positive: Brick Red
Negative: Blue

Question 4

Starch Test:
Solution: Iodine Solution

Answer 4

Positive: Blue-Black
Negative: Brown

Question 5

Protein Test:
Solution: Biuret Solution

Answer 5

Positive: Purple/Violet
Negative: Blue

Question 6

Fats & Oils Test:

Answer 6

Solution: Ethanol
Positive: Cloudy Emulsion

Question 7

Vitamin C Test:
Solution: DCPIP

Answer 7

Positive: Colourless
Negative: Blue

Question 8

DNA Structure

Answer 8

DNA: Made of two coiled strands = Double Helix

Bases:
A with T
C with G