Proteins quiz

Suitable for A/AS-level biology and Higher human biology students.
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1. How many different types of amino acid are used to make proteins?
a. 4
b. 20
c. 23
d. 38

2. Amino acids contain carbon, hydrogen, oxygen, and what other main element?
a. nitrogen
b. phosphorous
c. iron
d. magnesium

3. At what pH value do most enzymes work best?
a. pH 1
b. pH 3
c. pH 7
d. pH 11

4. Which of these is not a globular protein?
a. The skin protein collagen
b. The hormone insulin
c. The enzyme amylase
d. The oxygen carrier haemoglobin

5. Proteins are made from long, folded chain molecules. What are these chains called?
a. polysaccharides
b. polypeptides
c. polynucleotides
d. fatty acids

6. Disulphide bridges help to maintain which aspect of protein structure?
a. Primary structure
b. Secondary structure
c. Tertiary structure
d. Quaternary structure

7. Why is haemoglobin described as a 'conjugated protein'?
a. It is not made entirely of amino acids
b. It contains more than one chain
c. It binds to oxygen
d. It is fixed to the cell membrane

8. Which of these will not normally denature a protein?
a. Very high pH
b. Very low pH
c. Very high temperatures
d. Very low temperatures

9. The primary structure of a protein is held together by:
a. Hydrogen bonds
b. Ionic bonds
c. Glycosidic bonds
d. Peptide bonds

10. Which of these is a protein?
a. catalase
b. chlorophyll
c. cholesterol
d. cytosine

11. How does a competitive inhibitor prevent an enzyme from doing its job?
a. By denaturing the enzyme
b. By altering the pH
c. By binding to the active site
d. By immobilising the substrate

12. What type of reaction is catalysed by protease enzymes?
a. Condensation
b. Hydrolysis
c. Oxidation
d. Reduction

13. The poisonous gas cyanide, which prevents normal respiration, is an example of:
a. An enzyme
b. A coenzyme
c. An enzyme activator
d. An enzyme inhibitor

14. Enzymes are catalysts. What does this mean?
a. They break down other molecules
b. They bind to other molecules
c. They are made from smaller molecules
d. They speed up chemical reactions

15. Lipase, which breaks down fats in the small intestine, is:
a. A globular protein
b. A fibrous protein
c. An intracellular enzyme
d. Both A and C

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