Chapter 6: Cellular Repiration
In the first stage of cellular respiration (glycolysis), two molecules of pyruvate are produced. In the remaining stages of cellular respiration, a number of additional products are produced, such as __________. These other stages occur in the __________. View Available Hint(s) ATP ... mitochondria ATP ... cytoplasm water ... cytoplasm glucose ... mitochondria
ATP ... mitochondria
Which of these enters the citric acid cycle (also called the Krebs cycle)? NADH + H+ acetyl CoA G3P glucose pyruvate
acetyl CoA
Which of the following organisms perform cellular respiration? Select all that apply. a sunflower a honeybee a shark a palm tree a mushroom
all of them
A molecule that functions as the electron donor in a redox reaction __________. View Available Hint(s) gains electrons and becomes reduced gains electrons and becomes oxidized loses electrons and becomes reduced loses electrons and becomes oxidized
loses electrons and becomes oxidized
Primarily, cellular respiration serves to _____. View Available Hint(s) make ATP to power the cell's activities break down toxic molecules make food produce cell structures from chemical building blocks
make ATP to power the cell's activities
The electron transport chain is a series of electron carrier molecules. In eukaryotes, where can this structure be found? View Available Hint(s) mitochondria smooth endoplasmic reticulum rough endoplasmic reticulum plasma membrane
mitochondria
During glycolysis, a molecule of glucose is partially oxidized. What is the net gain of ATP and NADH for each glucose molecule during this chemical pathway? View Available Hint(s) 6 ATP and 10 NADH 32 ATP and 10 NADH 2 ATP and 2 NADH 4 ATP and 10 NADH
2 ATP and 2 NADH
In glycolysis, what starts the process of glucose breakdown? ATP FADH2 NADPH Pyruvate ADP
ATP
In glycolysis, ATP molecules are produced by _____. oxidative phosphorylation photosynthesis photophosphorylation cellular respiration substrate-level phosphorylation
substrate-level phosphorylation
How many NADH are produced by glycolysis? 3 2 4 5 1
2
In glycolysis there is a net gain of _____ ATP. 1 2 3 5 4
2
During electron transport, energy from _____ is used to pump hydrogen ions into the _____. NADH and FADH2 ... intermembrane space NADH ... mitochondrial matrix NADH ... intermembrane space NADH and FADH2 ... mitochondrial matrix acetyl CoA ... intermembrane space
NADH and FADH2 ... intermembrane space
Glycolysis is the only stage of cellular respiration that __________. View Available Hint(s) does not require ATP to make ATP requires ATP to make ATP requires oxygen to function does not release carbon dioxide as a by-product
requires ATP to make ATP
In the citric acid cycle (also called the Krebs cycle), ATP molecules are produced by _____. oxidative phosphorylation photosynthesis substrate-level phosphorylation photophosphorylation cellular respiration
substrate-level phosphorylation
Virtually all organisms on Earth use cellular respiration to produce ATP from sugar. ATP is then used to power cellular work. Which of the following is the correct equation for cellular respiration? sugar + O2 + sunlight → CO2 + H2O + ATP sugar + O2 → CO2 + H2O + ATP ATP + H2O + CO2 → O2 + sugar sugar + CO2 → O2 + H2O + ATP
sugar + O2 → CO2 + H2O + ATP
For each glucose that enters glycolysis, _____ NADH enter the electron transport chain. 6 2 4 10 0
10
The burning of food via cellular respiration must provide the average adult approximately _________ kilocalories per day. View Available Hint(s) 250 1,000 1,300 to 1800 2,200
2,200
Oxidative phosphorylation is responsible for nearly all the ATP produced in your body. Select the three true statements about oxidative phosphorylation. Oxidative phosphorylation is the second step in aerobic respiration, occurring after glycolysis but before the citric acid cycle. Some, but not all, of oxidative phosphorylation occurs inside mitochondria. Chemiosmosis is the final step in oxidative phosphorylation. NADH and FADH2 deliver electrons to the electron transport chain during oxidative phosphorylation. Without oxygen, oxidative phosphorylation would not occur.
Chemiosmosis is the final step in oxidative phosphorylation. NADH and FADH2 deliver electrons to the electron transport chain during oxidative phosphorylation. Without oxygen, oxidative phosphorylation would not occur.
Which of these is NOT a product of glycolysis? pyruvate water NADH + H+ ATP FADH2
FADH2
Each turn of the citric acid cycle generates one ATP and ___ additional energy-rich molecules: __________. View Available Hint(s) four; 2 NADH and 2 FADH2 two; 1 NADH and 1 FADH2 four; 3 NADH and 1 FADH2 three; 2 NADH and 1 FADH2
four; 3 NADH and 1 FADH2
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 treat people with bacterial infections. However, he can't do this because _____. View Available Hint(s) human cells also perform glycolysis; the drug might also poison them bacteria are facultative anaerobes; they usually don't need to perform glycolysis glycolysis produces so little ATP that the drug will have little effect bacteria do not perform glycolysis
human cells also perform glycolysis; the drug might also poison them
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. mixture needs more sugar because yeasts need a lot of energy before they can begin to produce alcohol. yeast used the alcohol as a carbon source. mixture needs more oxygen because yeasts need oxygen to break down sugar and get enough energy to produce alcohol.
mixture needs less oxygen because yeasts only produce alcohol in the absence of oxygen.
Sunlight is essential for the varied life on Earth. Sunlight provides energy to photosynthetic organisms by providing __________. View Available Hint(s) heat to leaves, which is used to synthesize chloroplasts the energy necessary to power the rearrangement of chemical bonds in H2O and CO2 heat to leaves, which is converted to useful energy for work the energy required to drive cellular respiration
the energy necessary to power the rearrangement of chemical bonds in H2O and CO2
The enzyme ATP synthase catalyzes the phosphorylation of ADP to form ATP. In eukaryotic cells, the energy needed for this endergonic reaction is directly derived from __________. View Available Hint(s) the movement of hydrogen ions across the mitochondrial membrane the reduction of NAD+ to form NADH the movement of FADH2 from the cytoplasm to the mitochondria the fermentation of pyruvate to form lactic acid
the movement of hydrogen ions across the mitochondrial membrane
We inhale O2 and we exhale CO2. Carbon dioxide is produced __________. View Available Hint(s) during the formation of pyruvate in the reaction that creates acetyl CoA (coenzyme A) from pyruvate when oxygen acquires electrons and protons at the end of the electron transport chain during the electron transfer steps of oxidative phosphorylation
in the reaction that creates acetyl CoA (coenzyme A) from pyruvate
mitochondrial cristae are an adaptation that permits the expansion of mitochondria as oxygen accumulates in the mitochondrial matrix. increases the space for more copies of the electron transport chain and ATP synthase complexes. carefully encloses the DNA housed within the mitochondrial matrix helps mitochondria divide during times of greatest cellular respiration.
increases the space for more copies of the electron transport chain and ATP synthase complexes.
The final electron acceptor of cellular respiration is _____. NADH CO2 oxygen water FADH2
oxygen
How do cells capture the energy released by cellular respiration? They store energy in molecules of carbon dioxide. They produce ATP. The energy is coupled to oxygen. They produce glucose.
They produce ATP.
Which of these is NOT a product of the citric acid cycle (also called the Krebs cycle)? FADH2 NADH + H+ CO2 ATP acetyl CoA
acetyl CoA
The O2 required for __________ is supplied by __________. View Available Hint(s) CO2 ... cellular respiration breathing ... cellular respiration cellular respiration ... breathing cellular respiration ... ATP
cellular respiration ... breathing
Which stage of cellular respiration appears to have evolved first? View Available Hint(s) citric acid cycle glycolysis Calvin cycle chemiosmosis and the electron transport pathway
glycolysis
Autotrophs use photosynthesis to convert the energy of sunlight into the chemical energy of sugar. Which of the following is the correct equation for photosynthesis? CO2 + H2O + sunlight → O2 + ATP O2 + H2O + sunlight → CO2 + sugar sugar + O2 → CO2 + H2O + sunlight CO2 + H2O + sunlight → O2 + sugar
CO2 + H2O + sunlight → O2 + sugar
Which of the following statements regarding aerobic cellular respiration is TRUE? View Available Hint(s) Glucose is completely oxidized to form carbon dioxide. Oxidative phosphorylation in the inner mitochondrial membrane produces NADH. The bulk of the ATP generated in cellular respiration in produced through substrate-level phosphorylation. Most of the energy captured from the breakdown of glucose occurs during glycolysis.
Glucose is completely oxidized to form carbon dioxide.
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 __________. View Available Hint(s) generate the ADP that is used to power biosynthetic pathways provide virtually all the heat needed to maintain body temperature create energy sources, such as glucose or amino acids, that are recycled back through respiration, thus allowing a continual source of ATP with relatively little food intake build amino acids, fats, and sugars
build amino acids, fats, and sugars
A single glucose molecule produces about 38 molecules of ATP through the process of cellular respiration. However, this only represents approximately 34% of the chemical energy present in this molecule. The rest of the energy from glucose is __________. View Available Hint(s) used to make water from hydrogen ions and oxygen stored as fat converted to heat used directly for energy
converted to heat
During redox reactions, the loss of electrons from one molecule is called reduction. protons from one molecule replace the electrons lost from another molecule. electrons are lost from one substance and added to another substance.
electrons are lost from one substance and added to another substance.
The electron transport chain is, in essence, a series of redox reactions that conclude cellular respiration. During these redox reactions, __________. View Available Hint(s) electrons are transferred through a series of electron acceptors embedded within the inner mitochondrial membrane ATP synthase allows hydrogen ions to move across the mitochondrial membrane all the carriers pump H+ across the mitochondrial membrane, forming a gradient that is used to drive ATP synthesis NADH is reduced as it donates electrons to the first complex involved in the electron transport chain
electrons are transferred through a series of electron acceptors embedded within the inner mitochondrial membrane
During cellular respiration, energy in glucose is carried by electrons. is released all at once. becomes stored in molecules of ammonia. is used to manufacture glucose.
is carried by electrons.
The proximate (immediate) source of energy for oxidative phosphorylation is _____. ATP kinetic energy that is released as hydrogen ions diffuse down their concentration gradient NADH and FADH2 ATP synthase substrate-level phosphorylation
kinetic energy that is released as hydrogen ions diffuse down their concentration gradient
A scientist wants to study the enzymes of the citric acid cycle in eukaryotic cells. What part of the cell would she use as a source of these enzymes? View Available Hint(s) mitochondrial matrix cytoplasm mitochondrial inner membrane plasma membrane
mitochondrial matrix
In cellular respiration, most ATP molecules are produced by _____. substrate-level phosphorylation oxidative phosphorylation photophosphorylation photosynthesis cellular respiration
oxidative phosphorylation
1. The transfer of electrons from one molecule to another is an oxidation-reduction reaction, or redox reaction. 2. In cellular respiration, glucose becomes oxidized to carbon dioxide (CO2) as it loses electrons (in hydrogen atoms). 3. In cellular respiration, oxygen becomes reduced to water (H2O) as it gains electrons (in hydrogen atoms) that came from glucose. 4. In cellular respiration, organic molecules become oxidized as NAD+ picks up electrons and H+ and becomes reduced to NADH. 5. NADH delivers electrons to an electron transport chain, which passes the electrons through carrier molecules in a series of redox reactions to the final electron acceptor, oxygen. 6. The energy released from the redox reactions in the electron transport chain is used by the cell to make ATP.
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An organism that can use energy from the sun to directly produce food is called a(n) autotroph. An organism that must consume other organisms to obtain nourishment is called a(n) heterotroph. During photosynthesis, the energy from the sun is used to make sugar molecules. During cellular respiration, the energy in sugar molecules is used to make molecules of ATP. ATP is the high-energy molecule used to power cellular work
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Oxidative phosphorylation could not occur without glycolysis and the citric acid cycle, because _____. View Available Hint(s) these two stages provide the water that is split during oxidative phosphorylation these two stages supply the electrons needed for the electron transport chain the electron transport chain requires the ATP produced during the first two stages these two stages provide the oxygen used as the final electron acceptor
these two stages supply the electrons needed for the electron transport chain