Exam 1(38 questions)

Exam 1 questions

Preview document (2 of 34 pages)

Chapter 1 Exam Questions
1. What statement is not true concerning hydrogen, oxygen, nitrogen, and carbon?
a. They make up 99% of the mass of most cells.
b. They are the lightest elements capable of efficiently forming one, two, three, and
four bonds respectively.
c. They are the only elements necessary for life.
d. They are the most abundant in terms of percentage of total number of atoms in
living organisms.
2. Hydrogen, oxygen, sulfur, and carbon are the lightest elements capable of efficiently
forming one, two, three, and four bonds respectively and thus are the building blocks of
99% of the mass of most cells.
a. True
b. False
3. Name the four most abundant elements in living organisms (percentage total).
a. Carbon oxygen nitrogen hydrogen
4. Match the term with the definition.
In vivo A
A. Studies conducted in a living organism.
In vitro B
B. Studies conducted using components
previously isolated from an organism that
are conducted in an artificial media and
environment.
Ex vivo C
C. Studies conducted in or on tissues harvested
from a living organism in an external
environment with minimal alteration of
natural conditions.
In silico D
D. Studies performed on a computer or by
computer simulation.
In situ E
E. Studies conducted “In position” that is in its
natural position or location.
5. ___in vivo________ studies are conducted in a living organism whereas ___in
vitro________ studies are conducted using components previously isolated from an
organism that are conducted in an artificial media and environment.
6. While in vitro experiments are remarkably revealing, the inside of a cell is quite different
from the inside of a test tube and thus in vitro results may be different than in vivo
experiments.
a. True
b. False
7. The randomness of disorder of the component of a chemical system are expressed as
enthalpy or H.
a. True
b. False
8. Which of the following is not a component of free-energy content (G)?
a. pH
b. enthalpy (H)
c. entropy (S)
d. temperature (T)
9. Match the variable with its definition.
G :B
A.Free energy content
H :D
B.entropy
S: F
C.temperature
ΔG: E
D.enthalpy
ΔH: A
E.change in enthalpy
T: C
F.free-energy change
10. The standard free-energy change for two reactions that sum to a third is simply the sum
of the two individual reactions. A positive value for ΔG0 indicates the reaction will tend
to occur spontaneously.
a. True
b. False
11. Given that the standard free-energy change for the reaction glucose + Pi = glucose 6-
phosphate is 13.8 kJ/mol, and the standard free-energy change for the reaction ATP =
ADP + Piis -30.5 kJ/mol, what is the free-energy change for the reaction glucose + ATP =
glucose 6-phosphate + ADP?
a. -16.7 kJ/mol
b. 16.7 kJ/mol
c. 13.8kJ/mol
d. -30.5 kJ/mol
12. When a system is at equilibrium, the rate of product formation exactly equals the rate at
which product is converted to reactant.
a. True
b. False
13. Virtually every chemical reaction in a cell occurs at a significant rate because of the
presence of enzymes that greatly enhance the rate of specific chemical reaction without
being consumed in the process.
a. True
b. False
14. All biological macromolecules are much less thermodynamically stable than their
monomeric subunits yet they are kinetically stable. What biomolecules catalyzes the
reactions to enhance the rate of reaction to allow the biochemical processes of the cell to
occur? Select the best answer.
a. Enzymes
b. Proteins
c. Metabolites
d. Chaperones