Edition Test Bank
By Moran, Horton,
Scrimgeour, Perry
,Chapter 1
Introduction to Biochemistry
1) Which elements account for more than 97% of the weight of most organisms?
A) C, H, N, Mg, O, S
B) C, H, N, O, P, S
C) C, H, N
D) Fe, C, H, O, P
E) Ca2+, K+, Na+, Mg2+, Cl-
Answer: B
Page Ref: Section 2
2) Proteins in biological membranes may be
A) porous.
B) attached to the membrane surface.
C) span the membrane.
D) All of the above
E) B and C only
Answer: D
Page Ref: Section 3
3) Which statement about cellulose is false?
A) It is the most abundant polysaccharide in nature.
B) Its monomers are joined by glycosidic bonds.
C) It is present in the stems of flowering plants.
D) The hydroxyl groups of neighboring cellulose molecules interact to form
strong, insoluble fibers.
E) It is a branched polymer of glucose.
Answer: E
Page Ref: Section 3
,4) When Keq of a reaction = 1, then
A) the forward reaction is faster than the reverse reaction.
B) the reverse reaction is faster than the forward reaction.
C) the forward and reverse reaction rate constants are equal.
D) more products are formed than reactants.
E) fewer products are formed than reactants.
Answer: C
Page Ref: Section 4
5) Which statement is true about a reaction with an equilibrium constant, Keq, equal to
1000?
A) The forward rate constant is 1000 times greater than the reverse rate constant.
B) The forward rate constant is 3 times greater than reverse rate constant.
C) The forward rate constant is 1000 times smaller than the reverse rate constant.
D) The forward rate constant is 3 times smaller than the reverse rate constant.
E) There is not enough information given to compare the forward and reverse rate
constants.
Answer: A
Page Ref: Section 4
6) The study of the energy changes during metabolic reactions is called .
A) bioinformatics
B) metabodynamics
C) thermometrics
D) bioenergetics
E) biological heat dynamics
Answer: D
Page Ref: Section 4
7) A spontaneous chemical reaction always has a change.
A) positive Gibbʹs free energy
B) negative Gibbʹs free energy
C) positive enthalpy
D) negative enthalpy
E) positive entropy
Answer: B
Page Ref: Section 4
, 8) Prokaryotes are valuable tools for biochemists because
A) E. coli is well-studied and typical of prokaryotes.
B) they contain as many genes as eukaryotic cells.
C) many of their chromosomes are sequenced.
D) they are not very diverse organisms.
E) All of the above
Answer: C
Page Ref: Section 6
9) Which cellular component carries out oxidation reactions, some of which
produce hydrogen peroxide?
A) peroxisomes
B) mitochondria
C) chloroplasts
D) lysosomes
E) vacuoles
Answer: A
Page Ref: Section 8
10)Why is it important that the enzymes in lysosomes are more active at acidic pH
than at neutral pH?
A) Since lysosomes are primarily found in the stomach acid of
mammals, their pH dependence allows for maximum efficiency for
the digestion of foodstuffs.
B) It prevents their diffusion out of the lysosomes.
C) It maximizes the interaction with their substrates which are always bases.
D) It prevents them from accidentally degrading the macromolecules in the cytosol.
E) It allows for regulation of their uptake by the mitochondria.
Answer: D
Page Ref: Section 8
11)Molecules from living cells cannot be synthesized outside of
living cells. Answer: FALSE
Page Ref: Section 1
12)Fermentation in the absence of cells demonstrated that metabolic processes
were chemical in nature.
Answer: TRUE
Page Ref: Section 1