Biology 152 Name:
Exam 1
Dr. Pelletier
Spring, 2008
Directions: For each of the following questions, select the single best answer by filling in the
appropriate answer on the supplied answer sheet. Please read all the responses before answering.
Each question is worth 2 points.
1. Oxygen is more electronegative than hydrogen.
2. The energy in an individual hydrogen bond is weaker than the energy in an individual covalent
bond.
3. A single element may exist as different isotopes such as 12C and 14C. This is due to differences in
the number of neutrons between the two isotopes.
4. If molecule “A” gives up electrons to molecule “B”, we would say that molecule “A” has been
oxidized.
5. Stomach acid has a pH of about 2, while the pH of the blood in a human is typically about 7.4.
Which of the following statements is true regarding the H+ concentration in the stomach as
compared to blood?
a. the concentration of H+ in the stomach is about 5 times greater than in the blood
b. the concentration of H+ in the stomach is about 100,000 times greater than in blood
c. the concentration of H+ in the blood is about 5 times greater than the stomach
d. the concentration of H+ in the blood is about 100,000 times greater than the stomach
6. In which molecule shown above is the carboxyl group shaded?
a. ethanol
b. acetaldehyde
c. acetic acid
d. alanine
e. pyruvate
7. In which molecule shown above is the hydroxyl group shaded?
a. ethanol
