1.   One experiment produced crystals of protein molecules that drug company researchers believe could advance the development of antiviral drugs.

2.   Protein molecules called enzymes are machines in the sense that each one causes a particular chemical reaction to take place.

3.   Some protein molecules are simply too large for microbes to handle.

4.   Synthesizing any new protein molecule from scratch takes a matter of minutes.

5.   The antibodies are protein molecules that can fit on to an allergen and inactivate it.

6.   They are smaller molecules than proteins, so they have to become attached to a protein molecule before they are activated.

7.   You can conceive of globular protein molecules folding from chains of left- and right-handed amino acids but not helical protein molecules.

8.   Protein molecules compose all the complex working parts of living cells.

9.   They are bigger than protein molecules but smaller than bacteria.