Biology chapter 6
Which of the following statements regarding the chemical grooming of pyruvate is false?
Each pyruvate molecule has a CO2 added and then joins with an NADH
A muscle cell deprived of molecular oxygen will convert glucose to lactic acid to __________.
Recycle NADH through fermentation
The proximate source of energy for oxidative phosphorylation is_____.
Kinetic energy that is released as hydrogen ions diffuse down their concentration gradients
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
A scientist wants to study the enzymes of the citric acid cycle in eukaryotic cells. What part of the cell should she use as a source of these enzymes?
Mitochondrial matrix
Given the relatively modest number of calories burned by anything but the most vigorous activities, why can people consume over 2000 kg calories 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 cellular respiration, organic molecules become oxidized as ____ picks up electrons and H+ and becomes reduced to NADH
NAD+
During electron transport, energy from _____ is used to pump hydrogen ions into the _____.
NADH and FADH2 ... intermembrane space
During fermentation, __________ that was produced during glycolysis is converted back to __________.
NADH; NAD+
In the electron transport chain, the final electron acceptor is
Oxygen
NADH delivers electrons to an electron transport chain, which passes the electrons through carrier molecules in a series of Reddox reactions to the final electron acceptor, ____
Oxygen
The final electron acceptor of cellular respiration is _____.
Oxygen
For each glucose that enters glycolysis, _____ NADH Enter the electron transport chain
10
How many molecules of NADH are produced during one round of glycolysis?
2
In glycolysis there is a net gain of _____ ATP
2
The label on the box of the breakfast cereal lists one serving as "200 calories" per serving. How many calories are actually in one serving?
200,000
How many NADH are produced by glycolysis?
two
In glycolysis, what starts the process of glucose breakdown?
ATP
The energy released from the redox reactions in the electron transport chain is used by the cell to make ____
ATP
Which of these and where use the citric acid cycle also called the Krebs cycle?
Acetyl CoA
Which of these is not a product of the citric acid cycle also called the Krebs cycle?
Acetyl CoA
Why is the citric acid cycle called a cycle?
Acetyl CoA binds to oxaloacetate and this compound is restored at the end of the cycle.
Which of the following processes produces the most ATP per molecule of glucose oxidized?
Aerobic respiration
In an experiment, mice were fed glucose (C6H12O6) containing a small amount of radioactive carbon. The mice were closely monitored, and after a few minutes radioactive carbon atoms showed up in __________.
Carbon dioxide
The O2 required for __________ is supplied by __________.
Cellular respiration....breathing
Which of these is not a product of glycolysis?
FADH2; from Citrix acid cycle
Each turn of the citric acid cycle generates 1 ATP and ______ additional energy rich molecules ____.
Four; 3 NADH and 1 FADH2
During cellular respiration, glucose is oxidized. However, an intermediate, _____, can be siphoned off and used to synthesize fats.
G3P
Which stage of cellular respiration appears to have evolved first?
Glycolysis
Marathon runners are long-distance runners (marathons are races that are 26.2 miles long). Studies have shown that the muscles of marathon runners contain an abundance of slow-twitch muscle cells. Which of the following statements about these fibers is true?
Slow-twitch fibers have lots of mitochondria to make ATP aerobically.
What is the ultimate fate of the electron's that are stripped from glucose during cellular respiration?
They are used to form water
How do cells capture the energy released during cellular respiration?
They produce ATP.
A friend tells you that he is going on a low-carb diet to lose weight because he thinks that carbs contain more energy than fats or protein. What would you tell your friend about his plan?
This is a bad idea because fats contain more hydrogen atoms then carbohydrates and protein.
The function of coenzyme A in the citric acid cycle is most like
a limousine driver dropping off a couple at the school prom
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
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
Which of the following is a result of glycolysis?
conversion of glucose to two three-carbon compounds
The transfer of ____ from one molecule to another is an oxidation reduction reaction, or redox reaction
electrons
When a cell uses fatty acids for aerobic respiration, it first hydrolyzes fats to
glycerol and fatty acids
A chemist has discovered a drug that blocks phosphoglucoisomerase, an enzyme that catalyzes the second reaction in glycolysis. He wants to use the drug to kill bacteria in people with infections. However, he cannot do this because __________.
human cells must also perform glycolysis; the drug might also poison them
Where does glycolysis occur in a eukaryotic cell?
in the cytoplasmic fluid
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
In cellular respiration, glucose ____ electrons, whereas ____ electrons.
loses ... oxygen gains
Oxidation is the ________, and reduction is the ________.
loss of electrons; gain of electrons
Some friends are trying to make wine in their basement. They've added yeast to a sweet grape juice mixture and have allowed the yeast to grow. After several days they find that sugar levels in the grape juice have dropped, but there's no alcohol in the mixture. The most likely explanation is that the
mixture needs less oxygen because yeasts only produce alcohol in the absence of oxygen
A child is born with a rare disease in which mitochondria are missing from skeletal muscle cells. However, the muscles still function. Physicians find that the
muscle contains large amounts of lactate following even mild physical exercise
Bacteria that are unable to survive in the presence of oxygen are called
obligate anaerobes
In cellular respiration, most ATP molecules are produced by ____.
oxidative phosphorylation
In cellular respiration, glucose becomes ____ to carbon dioxide as it loses electrons (hydrogen atoms)
oxidized
Bacteria have no membrane-enclosed organelles. However, some still generate ATP through cellular respiration. Where is the electron transport chain found in these organisms?
plasma membrane
In oxidative phosphorylation, electrons are passed from one electron carrier to another. The energy released is used to ____.
pump protons (H+) across the mitochondrial membrane
After glycolysis but before the citric acid cycle,
pyruvate is oxidized
In cellular respiration, oxygen becomes ____ to water as it gains electrons (in hydrogen atoms) that came from glucose.
reduced
In glycolysis, ATP molecules are produced by _____.
substrate-level phosphorylation
In the citric acid cycle also called the Krebs cycle, ATP molecules are produced by ____.
substrate-level phosphorylation
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