BIL 150 Exam 2 || A+ GUARANTEED
According to the fluid mosaic model of cell membranes, phospholipids _____. correct
answers Can move laterally along the plane of the membrane
Why are lipids and proteins free to move laterally? correct answers There are only weak
hydrophobic interactions in the interior of the membrane
Cell membranes are asymmetrical. What is the most likely explanation of the membranes
asymmetrical nature? correct answers The two sides of a cell membrane face different
environments and carry out different functions
Which of the following would most likely move through the lipid bilayer? correct answers
CO2 (Not K+, glucose, or an amino acid)
You are working on a team that is designing a new drug. For this drug to work, it must enter
the cytoplasm of specific target cells. Which of the following would be a factor that
determines whether the molecule selectively enters the target cells? correct answers
Similarity of the drug molecule to the other molecules transported by the target cells.
Which of the following is true of osmosis? correct answers In osmosis, water moves across a
membrane from areas of lower solute concentration to areas of higher solute concentration.
The force driving simple diffusion is _____, while the energy source for active transport is
_______. correct answers the concentration gradient; ATP
According to the induced fit hypothesis of enzyme catalysis, correct answers the binding of
the substrate changes the shape of the enzyme's active site
HIV is the virus that causes AIDS. In the mid-1990s, researchers discovered an enzyme in
HIV called protease. Once the enzyme's structure was known, researchers began looking for
drugs that would fit into the active site and block it. If this strategy for stopping HIV
infections were successful, it would be an example of what phenomenon? correct answers
competitive inhibition
You have isolated a previously unstudied protein, identified its complete structure in detail,
and determined that it catalyzes the breakdown of a large substrate. You notice it has two
binding sites. One of these is large, apparently the bonding site for the large substrate; the
other is small, possibly a binding site for a regulatory molecule. What do these findings tell
you about the mechanism of this protein? correct answers It is probably an enzyme that
works through allosteric regulation.
Biological systems use free energy based on empirical data that all organisms require a
constant energy input. The first law of thermodynamics states that energy can be neither
created nor destroyed. For living organisms, which of the following statements is an
important consequence of this first law? correct answers The organism must ultimately obtain
all the necessary energy for life from its environment.
Which of the listed statements describes the results of the following reaction? C6H12O6 + 6
O2 → 6 CO2 + 6 H2O + Energy correct answers C6H12O6 is oxidized and O2 is reduced.
, The oxygen consumed during cellular respiration is involved directly in which process or
event? correct answers accepting electrons at the end of the electron transport chain
The free energy for the oxidation of glucose to CO2 and water is -686 kcal/mol and the free
energy for the reduction of
NAD+ to NADH is +53 kcal/mol. Why are only two molecules of NADH formed during
glycolysis when it appears that as many as a dozen could be formed? correct answers Most of
the free energy available from the oxidation of glucose remains in pyruvate, one of the
products of glycolysis.
In glycolysis, for each molecule of glucose oxidized to pyruvate correct answers two
molecules of ATP are used and four molecules of ATP are produced
If you were to add one of the eight citric acid cycle intermediates to the culture medium of
yeast growing in the laboratory, what do you think would happen to the rates of ATP and
carbon dioxide production? correct answers The rates of ATP production and carbon dioxide
production would both increase.
The chemiosmotic hypothesis is an important concept in our understanding of cellular
metabolism in general because it explains correct answers how ATP is synthesized by a
proton motive force
The hydrolysis of ATP: ATPWhat is the source of the 7.3 kcal/mol released in this reaction?
correct answers the difference between the potential energy in the bonds of ATP and the
water molecule, minus the potential energy in
the bonds of ADP and Pi
When an individual is exercising heavily and when the muscle becomes oxygen-deprived,
muscle cells convert pyruvate to lactate. What happens to the lactate in skeletal muscle cells?
correct answers It is taken to the liver and converted back to pyruvate.
Phosphofructokinase is an allosteric enzyme that catalyzes the conversion of fructose 6-
phosphate to fructose 1,6-bisphosphate, an early step of glycolysis. In the presence of
oxygen, an increase in the amount of ATP in a cell would be expected to correct answers
inhibit the enzyme and thus slow the rates of glycolysis and the citric acid cycle.
During aerobic respiration, electrons travel downhill in which sequence? correct answers
glucose → NADH → electron transport chain → oxygen
You have a friend who lost 7 kg (about 15 pounds) of fat on a regimen of strict diet and
exercise. How did the fat leave her body? correct answers It was released as CO2 and H2O
Why is glycolysis considered to be one of the first metabolic pathways to have evolved?
correct answers It does not involve organelles or specialized structures, does not require
oxygen, and is present in most organisms.
A young dog has never had much energy. He is brought to a veterinarian for help and she
decides to conduct several diagnostic tests. She discovers that the dog's mitochondria can use
only fatty acids and amino acids for respiration, and his cells produce more lactate than
According to the fluid mosaic model of cell membranes, phospholipids _____. correct
answers Can move laterally along the plane of the membrane
Why are lipids and proteins free to move laterally? correct answers There are only weak
hydrophobic interactions in the interior of the membrane
Cell membranes are asymmetrical. What is the most likely explanation of the membranes
asymmetrical nature? correct answers The two sides of a cell membrane face different
environments and carry out different functions
Which of the following would most likely move through the lipid bilayer? correct answers
CO2 (Not K+, glucose, or an amino acid)
You are working on a team that is designing a new drug. For this drug to work, it must enter
the cytoplasm of specific target cells. Which of the following would be a factor that
determines whether the molecule selectively enters the target cells? correct answers
Similarity of the drug molecule to the other molecules transported by the target cells.
Which of the following is true of osmosis? correct answers In osmosis, water moves across a
membrane from areas of lower solute concentration to areas of higher solute concentration.
The force driving simple diffusion is _____, while the energy source for active transport is
_______. correct answers the concentration gradient; ATP
According to the induced fit hypothesis of enzyme catalysis, correct answers the binding of
the substrate changes the shape of the enzyme's active site
HIV is the virus that causes AIDS. In the mid-1990s, researchers discovered an enzyme in
HIV called protease. Once the enzyme's structure was known, researchers began looking for
drugs that would fit into the active site and block it. If this strategy for stopping HIV
infections were successful, it would be an example of what phenomenon? correct answers
competitive inhibition
You have isolated a previously unstudied protein, identified its complete structure in detail,
and determined that it catalyzes the breakdown of a large substrate. You notice it has two
binding sites. One of these is large, apparently the bonding site for the large substrate; the
other is small, possibly a binding site for a regulatory molecule. What do these findings tell
you about the mechanism of this protein? correct answers It is probably an enzyme that
works through allosteric regulation.
Biological systems use free energy based on empirical data that all organisms require a
constant energy input. The first law of thermodynamics states that energy can be neither
created nor destroyed. For living organisms, which of the following statements is an
important consequence of this first law? correct answers The organism must ultimately obtain
all the necessary energy for life from its environment.
Which of the listed statements describes the results of the following reaction? C6H12O6 + 6
O2 → 6 CO2 + 6 H2O + Energy correct answers C6H12O6 is oxidized and O2 is reduced.
, The oxygen consumed during cellular respiration is involved directly in which process or
event? correct answers accepting electrons at the end of the electron transport chain
The free energy for the oxidation of glucose to CO2 and water is -686 kcal/mol and the free
energy for the reduction of
NAD+ to NADH is +53 kcal/mol. Why are only two molecules of NADH formed during
glycolysis when it appears that as many as a dozen could be formed? correct answers Most of
the free energy available from the oxidation of glucose remains in pyruvate, one of the
products of glycolysis.
In glycolysis, for each molecule of glucose oxidized to pyruvate correct answers two
molecules of ATP are used and four molecules of ATP are produced
If you were to add one of the eight citric acid cycle intermediates to the culture medium of
yeast growing in the laboratory, what do you think would happen to the rates of ATP and
carbon dioxide production? correct answers The rates of ATP production and carbon dioxide
production would both increase.
The chemiosmotic hypothesis is an important concept in our understanding of cellular
metabolism in general because it explains correct answers how ATP is synthesized by a
proton motive force
The hydrolysis of ATP: ATPWhat is the source of the 7.3 kcal/mol released in this reaction?
correct answers the difference between the potential energy in the bonds of ATP and the
water molecule, minus the potential energy in
the bonds of ADP and Pi
When an individual is exercising heavily and when the muscle becomes oxygen-deprived,
muscle cells convert pyruvate to lactate. What happens to the lactate in skeletal muscle cells?
correct answers It is taken to the liver and converted back to pyruvate.
Phosphofructokinase is an allosteric enzyme that catalyzes the conversion of fructose 6-
phosphate to fructose 1,6-bisphosphate, an early step of glycolysis. In the presence of
oxygen, an increase in the amount of ATP in a cell would be expected to correct answers
inhibit the enzyme and thus slow the rates of glycolysis and the citric acid cycle.
During aerobic respiration, electrons travel downhill in which sequence? correct answers
glucose → NADH → electron transport chain → oxygen
You have a friend who lost 7 kg (about 15 pounds) of fat on a regimen of strict diet and
exercise. How did the fat leave her body? correct answers It was released as CO2 and H2O
Why is glycolysis considered to be one of the first metabolic pathways to have evolved?
correct answers It does not involve organelles or specialized structures, does not require
oxygen, and is present in most organisms.
A young dog has never had much energy. He is brought to a veterinarian for help and she
decides to conduct several diagnostic tests. She discovers that the dog's mitochondria can use
only fatty acids and amino acids for respiration, and his cells produce more lactate than
