1. _____ Proteins are biological molecules made of ________________.
A. amino acids
B. nucleotides
C. Sugars
D. glycerol

2. _____ When a protein makes it easier for a biological reaction to happen, it is acting as a/an
A. structural protein
B. messenger
C. enzyme
D. transporter

3. _____ What role(s) do proteins play?
A. enzymes
B. transporter molecule
C. immunity (antibodies)
D. messenger
E. locomotion (muscles)
F. structure
G. all of the above

4. _____ Keratin and collagen are examples of what type of protein?
A. antibody
B. enzyme
C. structural
D. transporter

5. _____ Enzymes play an important role for living things because
A. they reduce the energy required called the activation barrier.
B. they increase the energy required called the activation barrier.
C. they transport oxygen via hemoglobin to our cells. D. they (antibodies) protect us from viruses.