Biological Molecules
61 questions· page 1 of 7
Globulin is a substance that can be detected by the biuret test.
Which type of substance is globulin?
Options
A fat
B oil
C protein
D reducing sugar
Cellulose and glucose are carbohydrates.
Cellulose is a large molecule made from a long chain of smaller glucose molecules.
One cellulose molecule is long. One glucose molecule is long.
How many glucose molecules are found in this cellulose molecule?
Options
A
B
C
D
Four test-tubes contain starch solution and amylase. They are placed in water-baths at different temperatures and provided with different pHs, as shown in the table. All other conditions are kept the same.
After 30 minutes, iodine solution is added to each test-tube. The contents of three of the test-tubes turns blue-black.
In which test-tube are the contents yellow-brown?
Options
| temperature / | pH | |
|---|---|---|
| A | 35 | 2.5 |
| B | 35 | 6.9 |
| C | 75 | 2.5 |
| D | 75 | 6.9 |
The key shows shapes representing small food molecules.
Large food molecules are made from smaller food molecules.
Which diagram represents part of a glycogen molecule?
Options
Which type of food molecule has the element nitrogen in its structure?
Options
A amino acid
B fatty acid
C glucose
D glycerol
Which test can be used to determine the presence of glucose?
Options
A Benedict’s test
B biuret test
C ethanol emulsion test
D iodine test
The diagram shows an amino acid molecule.
Which part of the amino acid molecule is removed and used to make urea?
Options
A A
B B
C C
D D
Which statements are correct?
- A molecule of DNA consists of many nucleotides.
- A molecule of glycogen consists of many glucose molecules.
- A molecule of lipid consists of glycerol and amino acid molecules.
Options
A 1, 2 and 3
B 1 and 2 only
C 1 and 3 only
D 2 and 3 only
Which biological molecule contains the chemical elements carbon, hydrogen, nitrogen and phosphorus?
Options
A DNA
B cellulose
C lipid
D starch
A student tested a sample of food.
The results are shown.
| colour after adding Benedict's solution and heating | colour after adding biuret reagent | colour after adding iodine solution |
|---|---|---|
| red | purple | yellow / brown |
Which nutrients were in the food?
Options
A protein, starch and reducing sugar
B protein and starch only
C protein and reducing sugar only
D starch and reducing sugar only