2. In a dipeptide, two amino acids bond to each other via a(n) _____ reaction to form
an _____ bond.
a. hydrolysis....ester
*b. dehydration....amide
c. hydrolysis....amide
d. dehydration....ester
3. The secondary structure of a protein is held together mostly by:
a. amide bonds
b. peptide bonds
*c. hydrogen bonds
d. disulfide bonds
4. Name the four most common functions of proteins in living organisms.
structural, carrier, messenger, enzyme
5. In the enzyme catalyzed reaction in which ethanal is converted to ethanoic acid,
ethanal is referred to as:
*a. the substrate of the enzyme
b. the competitive inhibitor of the enzyme
c. the activator of the enzyme
d. the feedback inhibitor of the enzyme
6. Describe the process of feedback inhibition.
The product of a sequence of enzyme-catalyzed reactions inhibits
the fuction of an enzyme that catalyzes one of the earlier reactions in the sequence, thus
limiting (or controling) the production of that chemical.
7. What happens to the protein that we eat?
The protein we eat is broken down into amino acids by hydrolysis
reactions. Those amino acids can then be assembled into protein that we need by
enzyme-catalyzed dehydration reactions.
8. What steps or processes does protein go through when it is used to provide energy?
To provide energy, protein is broken down into amino acids by
hydrolysis reactions, then the amino acids are deaminated and converted into chemicals
which enter into the citric acid cycle.
9. Why would an enzyme hydrolyze ATP at the same time that it is catalyzing another
reaction?
If an enzyme is catalyzing an endothermic reaction, it would need
to utilize energy from the hydrolysis of ATP to drive the endothermic reaction.
10. What kinds of reactions must amino-acids endure to become proteins?
Amino acids become proteins through a sequence of
enzyme-catalyzed dehydration reactions.
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Sue Eggling
Clackamas Community College
©2001, 2003 Clackamas Community College, Hal Bender
