Exam 2 Flashcards
(38 cards)
If the free energy of X = +10.0, the following apply to the coupled reaction
the coupled reaction will represent an endergonic reaction
If the free energy of X = +2.4, the following apply to the coupled reaction
the coupled reaction will occur
The lock-and-key analogy for enzymes applies to the specificity of enzymes
) binding to their substrate
Which of the following is most similar in structure to ATP?
an RNA nucleotide
Which of the following statements is most true?
A) consist of a hydrophilic head and two hydrophobic tails
B) self-assemble into a bilayer
C) are the major component of all cell membranes
D) amphipathic molecule
E) all of the above
E!
Which of these molecules is most easily able to pass through the lipid bilayer via passive diffusion?
H2O
The following mechanisms of endocytosis are utilized by cells:
receptor-mediated endocytosis
Phospholipids have the following characteristics
A) consist of a hydrophilic head and two hydrophobic tails
B) self-assemble into a bilayer
C) are the major component of all cell membranes
D) amphipathic molecule
E) all of the above
E!
Which of the following types of reactions would decrease the entropy within a cell?
B) anabolic reactions
) For living organisms, which of the following is an important consequence of the first law of thermodynamics?
D) the organism ultimately must obtain all of the necessary energy for life from its environment
Which of these processes require energy (ATP)?
A) diffusion
B) osmosis
C) facilitated diffusion
D) active transport
E) none of the above
Active Transport
Reactants capable of interacting to form products in a chemical reaction
must first overcome a thermodynamic barrier known as the reaction’s
activation energy
A noncompetitive inhibitor decreases the rate of an enzyme reaction by
A) binding at the active site of the enzyme
B) changing the free energy change of the reaction
C) acting as a coenzyme for the reaction
D) changing the shape of the enzyme’s active site
E) none of the above
D changing the shape of the enzymes active site
According to the fluid mosaic model of cell membranes, phospholipids _____.
A) frequently flip-flop from one side of the membrane to the other
B) can move laterally along the plane of the membrane
C) have hydrophilic tails in the interior of the membrane
D) occur in an uninterrupted bilayer, with membrane proteins restricted to the surface of the membrane
E) none of the above
B can move laterally along the plane of the mebrane
When hydrogen ions are pumped from the mitochondrial matrix across the inner membrane and into the intermembrane space, the
result is the
A) formation of ATP
B) reduction of NAD+
C) restoration of the NA+/K+ balance across the membrane
D) creation of a proton gradient
E) lowering of pH in the mitochondrial matrix
D creation of a proton gradient
The key enzyme which regulates glycolysis through allosteric binding of ATP and its products is:
A) hexokinase
B) ATP synthase
C) rubisco
D) coenzyme A
E) none of the above
E. none of the above
pyruvate kinase
Energy in the form of ATP is initially invested during
A) citric acid cycle
B) oxidative phosphorylation
C) alcohol fermentation
D) lactic acid fermentation
E) none of the above
E none of the above
the first half of glycolysis
Which of the following occurs in the mitochondria of a
eukaryotic cell?
A) glycolysis
B) fermentation
C) Calvin cycle
D) light reactions
E) none of the above
E none of the above
oxidative phosphorylation
Which of the listed statements describes the results of the
following reaction?
C6H12O6 + 6 O2 → 6 CO2 + 6 H2O + Energy
A) O2 is reduced and CO2 is oxidized
B) C6H12O6 is oxidized and O2 is reduced
C) O2 is oxidized and H2O is reduced
D) CO2 is reduced and O2 is oxidized
E) none of the above
B C6H12O6 is oxidized and O2 is reduced
) During aerobic respiration, electrons travel downhill in which sequence?
A) glucose pyruvate ATP oxygen
B) food NADH electron transport chain oxygen
C) glucose ATP electron transport chain NADH
D) food citric acid cycle ATP NAD+
E) food glycolysis citric acid cycle NADH ATP
B food NADH electron transport chain oxygen
What is the primary function of the Calvin Cycle?
A) use ATP to release carbon dioxide
B) use NADPH to release carbon dioxide
C) synthesize simple sugars from carbon dioxide
D) split water and release oxygen
E) transport RuBP out of the chloroplast
C synthesize simple sugars from carbon dioxide
The primary role of oxygen in cellular respiration is to
A) catalyze the reactions of glycolysis
B) combine with carbon, forming CO2
C) combine with lactate, forming pyruvate
D) act as an acceptor for electrons and hydrogen, forming water
E) yield energy in the form of ATP as it is passed down the respiratory chain
D act as an acceptor for electrons and hydrogen, forming water
A chemical reaction that has a positive ∆G is best described as _____.
A) endergonic
B) enthalpic
C) exergonic
D) spontaneous
E) none of the above
A endergonic
Which of the following is true for anabolic pathways?
A) they are usually highly spontaneous chemical reactions
B) they consume energy to build up polymers from monomers
C) they release energy as they degrade polymers to monomers
D) they do not depend on enzymes
E) none of the above
B they consume energy to build up polymers form monomers
