Chapter 6 Biology
Which of the following statements regarding photosynthesis and cellular respiration is true?
Photosynthesis occurs in chloroplasts, and cellular respiration occurs in mitochondria
A gram of fat oxidized by cellular respiration produces approximately __________ as much ATP as a gram of carbohydrate.
twice
Fat is the most efficient molecule for long-term energy storage even compared to carbohydrates because _____.
with their numerous hydrogen atoms, fats provide an abundant source of high-energy electrons
Fat is the most efficient molecule for long-term energy storage, even compared to carbohydrates, because _____.
with their numerous hydrogen atoms, fats provide an abundant source of high-energy electrons
The function of cellular respiration is to _____.
extract usable energy from glucose
__________ is to a mitochondrion as __________ is to a chloroplast.
O2 ... CO2
Which of the following statements about the energy yield of aerobic respiration is false?
Oxidative phosphorylation resulting from 1 glucose molecule yields 12 ATP molecules.
During chemiosmosis,
ATP is synthesized when H+ ions move through a channel in ATP synthase.
Yeasts can produce ATP by either fermentation or oxidative phosphorylation; thus, they are
facultative anaerobes.
If you consume 1 g of each of the following, which will yield the most ATP?
fat
If ATP accumulates in a cell,
feedback inhibition slows down cellular respiration.
Humans use the calories they obtain from ________ as their source of energy.
food
As a result of glycolysis, there is a net gain of ________ ATP(s).
2
How many molecules of NADH are produced during glycolysis?
2
Substrate-level phosphorylation directly generates ATP during a chemical reaction. As a single molecule of glucose is completely oxidized in the presence of oxygen, how many molecules of ATP are made by substrate-level phosphorylation?
4 ATP
Humans use about ________ of their daily calories to maintain brain cells and power other life-sustaining activities.
75%
The overall equation for the cellular respiration of glucose is
C6H12O6 + 6 O2 → 6 CO2 + 6 H2O + energy.
Which of the following best describes the electron transport chain?
Electrons pass from one carrier to another, releasing a little energy at each step.
Given the relatively modest number of calories burned by anything but the most vigorous activities, why can people consume over 2,000 kilocalories a day, yet maintain a healthy body weight?
Most of the energy consumed in food is spent maintaining the body's functions, so only a fraction of food energy needs to be burned in exercise.
In the absence of oxygen, cells need a way to regenerate which compound?
NAD+
At the end of the citric acid cycle, most of the energy remaining from the original glucose is stored in
NADH
an electron carrier, such as __________, acts as an energy-storage molecule when it is __________.
NADH ... reduced
The electron transport chain is, in essence, a series of redox reactions that conclude cellular respiration. During these redox reactions, _____.
NADH is oxidized, which then reduces an electron acceptor in the electron transport chain
During fermentation, __________ that was produced during glycolysis is converted back to __________.
NADH; NAD+
How do cells capture the energy released by cellular respiration?
They produce ATP.
The functioning of an electron transport chain is analogous to
a Slinky toy going down a flight of stairs.
The function of coenzyme A in the citric acid cycle is most like
a limousine driver dropping off a couple at the school prom.
What two-carbon precursor molecule from carbohydrate metabolism is used to produce fatty acids?
acetyl-CoA
Which of the following processes produces the most ATP per molecule of glucose oxidized?
aerobic respiration
In yeast cells,
alcohol is produced after glycolysis.
When proteins are used as a source of energy for the body, the proteins
are converted mainly into intermediates of glycolysis or the citric acid cycle.
Using the ATP generated during cellular respiration, the intermediates of glycolysis and the citric acid cycle, such as pyruvate and acetyl CoA, can be siphoned off and used to __________.
build amino acids, fats, and sugars
By-products of cellular respiration include
carbon dioxide and water.
Which of the following is a result of glycolysis?
conversion of glucose to two three-carbon compounds
During cellular respiration, NADH
delivers its electron load to the first electron carrier molecule.
Pyruvate
forms at the end of glycolysis.
During cellular respiration, glucose is oxidized. However, an intermediate __________ can be siphoned off and used to synthesize fats.
glyceraldehyde-3-phosphate
During which of the following phases of cellular respiration does substrate-level phosphorylation take place?
glycolysis and the citric acid cycle
Which of the following options lists the stages in cellular respiration in the correct order?
glycolysis, the citric acid cycle, and oxidative phosphorylation
In muscle cells, fermentation produces _____.
lactate and NAD+
Sports physiologists at an Olympic training center want to monitor athletes to determine at what point their muscles begin to function anaerobically. They could do this by checking for a buildup of _____.
lactic acid
Recent data suggests that heat-generating brown fat is most active in __________.
lean people exposed to cold temperatures
In cellular respiration, glucose _____ electrons, whereas _____ electrons.
loses ... oxygen gains
A molecule is oxidized when it _____.
loses an electron
A molecule that functions as the electron donor in a redox reaction __________.
loses electrons and becomes oxidized
Some human cells, such as nerve cells, are restricted to aerobic respiration to recycle NADH and FADH2. If these cells are deprived of oxygen, then _____.
oxidative phosphorylation would come to a halt because there wouldn't be any oxygen to "pull" the electrons down the transport chain
The conversion of CO2 and H2O into organic compounds using energy from light is called
photosynthesis.
After glycolysis but before the citric acid cycle,
pyruvate is oxidized.
Sunlight is essential for the varied life on Earth. Sunlight provides energy to photosynthetic organisms by providing __________.
the energy necessary to power the rearrangement of chemical bonds in H2O and CO2
A kilocalorie is defined as
the quantity of heat needed to raise the temperature of 1 kg of water by 1°C.
The energy yield from the breakdown of a single molecule of glucose does not depend upon
the supply of carbon dioxide.
In fermentation, ________ is ________.
NADH; oxidized
Besides sugars and fats, organisms can use other molecules as fuel for cellular respiration. When protein molecules are used, _____ are produced as waste.
amino groups
Which of the following are products of cellular respiration?
energy to make ATP and carbon dioxide
During cellular respiration, the energy in glucose
is carried by electrons.
Respiration ________, and cellular respiration ________.
is gas exchange; produces ATP
When a car engine burns gasoline, the results of the reaction are similar to when cells burn glucose. Both reactions release carbon dioxide and water. In cells, the chemical energy in food is converted to ATP and heat. In a moving car, the chemical energy in gasoline is converted to _____.
kinetic energy and heat
Oxidation is the ________, and reduction is the ________.
loss of electrons; gain of electrons
The processes of photosynthesis and cellular respiration are complementary. During these energy conversions, some energy is
lost in the form of heat.
Primarily, cellular respiration serves to _____.
make ATP to power the cell's activities
Lungs are to breathing as _____ are to cellular respiration.
mitochondria
Bacteria that are unable to survive in the presence of oxygen are called
obligate anaerobes.
The end products of the citric acid cycle include all of the following except
pyruvate.
A muscle cell deprived of molecular oxygen will convert glucose to lactic acid to __________.
recycle NADH through fermentation