bio chapter 9
The immediate energy source that drives ATP synthesis by ATP synthase during oxidative phosphorylation is the
H+ concentration across the membrane holding ATP synthase
In glycolysis, ATP molecules are produced by _____. photosynthesis cellular respiration substrate-level phosphorylation photophosphorylation oxidative phosphorylation
substrate-level phosphorylation
Which of these is NOT a product of glycolysis? FADH2 ATP pyruvate NADH
FADH2
NADH and FADH2 are both electron carriers that donate their electrons to the electron transport chain. The electrons ultimately reduce O2 to water in the final step of electron transport. However, the amount of ATP made by electrons from an NADH molecule is greater than the amount made by electrons from an FADH2 molecule.
Fewer protons are pumped across the inner mitochondrial membrane when FADH2 is the electron donor than when NADH is the electron donor
In the combined processes of glycolysis and cellular respiration, what is consumed and what is produced? .
Glucose is consumed, and carbon dioxide is produced
What process occurs in box a?
Glycolysis occurs in the cytosol.
In glycolysis there is a net gain of _____ ATP. 5 1 2 4 3
2
Each of the four stages of cellular respiration occurs in a specific location inside or outside the mitochondria. These locations permit precise regulation and partitioning of cellular resources to optimize the utilization of cellular energy. Match each stage of cellular respiration with the cellular location in which it occurs. Labels may be used once, more than once, or not at all.
1) Oxidized 2) Reduced 3) Glucose 4) Pyruvate 5) NAD⁺ 6) NADH
How many NADH are produced by glycolysis? 1 2 3 4 5 2
2
Assuming that the y-axis tick marks will be separated by 1.0 (0.0, 1.0, 2.0, and so on), what is the largest value that should appear on the y-axis? 0 5.0 9.0 25.0
9.0
Carbon atoms in acetyl CoA formation and the citric acid cycle During acetyl CoA formation and the citric acid cycle, all of the carbon atoms that enter cellular respiration in the glucose molecule are released in the form of CO2. Use this diagram to track the carbon-containing compounds that play a role in these two stages. Drag the labels from the left (which represent numbers of carbon atoms) onto the diagram to identify the number of carbon atoms in each intermediate in acetyl CoA formation and the citric acid cycle. Labels may be used more than once.
A) 2 C B) 6 C C) 6 C D) 5 C E) 4 C F) 4 C G) 4 C H) 4 C I) 4 C
in glycolysis, what starts the process of glucose oxidation? FADH2 ADP ATP hexokinase NADPH
ATP
The effects of anaerobic conditions How would anaerobic conditions (when no O2 is present) affect the rate of electron transport and ATP production during oxidative phosphorylation? (Note that you should not consider the effect on ATP synthesis in glycolysis or the citric acid cycle.)
Both electron transport and ATP synthesis would stop.
TP synthesis in glycolysis: substrate-level phosphorylation The ATP that is generated in glycolysis is produced by substrate-level phosphorylation, a very different mechanism than the one used to produce ATP during oxidative phosphorylation. Phosphorylation reactions involve the addition of a phosphate group to another molecule. Sort the statements into the appropriate bin depending on whether or not they correctly describe some aspect of substrate-level phosphorylation in glycolysis.
Correct: -One of the substrates is a molecule derived from the breakdown of glucose -An enzyme is required in order for the reaction to occur -A bond must be broken between an organic molecule and phosphate before ATP can form. Incorrect: -The phosphate group added to ADP to make ATP comes from free inorganic phosphate ions. -The enyzmes involved in ATP synthesis must be attached to a membrane to produce ATP.
Net redox reaction in acetyl CoA formation and the citric acid cycle In the sequential reactions of acetyl CoA formation and the citric acid cycle, pyruvate (the output from glycolysis) is completely oxidized, and the electrons produced from this oxidation are passed on to two types of electron acceptors. Drag the labels on the left to show the net redox reaction in acetyl CoA formation and the citric acid cycle. Note that two types of electron carriers are involved.
It is easier to remove electrons and produce CO2 from compounds with three or more carbon atoms than from a two-carbon compound such as acetyl CoA.
A glucose molecule is completely broken down to carbon dioxide and water in glycolysis and the citric acid cycle, but together these two processes yield only a few molecules of ATP. What happened to most of the energy that the cell obtains from the oxidation of glucose?
It is stored in NADH and FADH2
Which of the following describes the process of glycolysis?
It represents the first stage in the chemical oxidation of glucose by a cell.
Part E Which of the following graphs correctly represents the data from the experiment?
Low, Normal Elevated Check to be sure that the axes are labeled correctly
Now that you have determined which variable goes on each axis, the graph can be constructed. Assuming that the x-axis tick marks will be used to identify the thyroid hormone level of each type of rat, what bars should appear on the x-axis? Cold, Normal, Hot 4.3, 4.8, 8.7 Low, Normal, Elevated Low, Medium, High
Low, Normal, Elevated
From the following compounds involved in cellular respiration, choose those that are the net inputs and net outputs of glycolysis. Drag each compound to the appropriate bin. If the compound is not involved in glycolysis, drag it to the "not input or output" bin. Net Input: ADP, NAD⁺, Glucose Net Output: ATP, NADH and Pyruvate, not input or output: O₂, CO₂, coenzyme A and acetyl CoA
Net Input: ADP, NAD⁺, Glucose Net Output: ATP, NADH and Pyruvate, not input or output: O₂, CO₂, coenzyme A and acetyl CoA
In the citric acid cycle (also known as the Krebs cycle), acetyl CoA is completely oxidized. From the following compounds involved in cellular respiration, choose those that are the net inputs and net outputs of the citric acid cycle. Drag each compound to the appropriate bin. If a compound is not involved in the citric acid cycle, drag it to the "not input or output" bin. (Note that not all of the inputs and outputs of the citric acid cycle are included.)
Net Input: Acetyl CoA, NAD⁺, ADP Net Output: Coenzyme A, CO₂, NADH, ATP Not Input or Output: Pyruvate, Glucose, O₂
In the last stage of cellular respiration, oxidative phosphorylation, all of the reduced electron carriers produced in the previous stages are oxidized by oxygen via the electron transport chain. The energy from this oxidation is stored in a form that is used by most other energy-requiring reactions in cells. From the following compounds involved in cellular respiration, choose those that are the net inputs and net outputs of oxidative phosphorylation. Drag each compound to the appropriate bin. If a compound is not involved in oxidative phosphorylation, drag it to the "not input or output" bin. (Note that not all of the inputs and outputs of oxidative phosphorylation are listed.)
Net Input: NADH, ADP, O₂ Net Output: NAD⁺, ATP, and Water Not Input or Output: Pyruvate, Glucose, Acetyl CoA, Coenzyme A and CO₂.
In acetyl CoA formation, the carbon-containing compound from glycolysis is oxidized to produce acetyl CoA. From the following compounds involved in cellular respiration, choose those that are the net inputs and net outputs of acetyl CoA formation. Drag each compound to the appropriate bin. If a compound is not involved in acetyl CoA formation, drag it to the "not input or output" bin. (Note that not all of the inputs and outputs of acetyl CoA formation are included.) Net Input: NAD⁺, coenzyme A, pyruvate Net Output: NADH, acetyl CoA, CO₂ not input or output: O₂, ADP, glucose and ATP
Net Input: NAD⁺, coenzyme A, pyruvate Net Output: NADH, acetyl CoA, CO₂ not input or output: O₂, ADP, glucose and ATP
What molecule is indicated by the letter D? a. glucose b. oxygen c. ATP d. pyruvate e. water b. oxygen
Oxygen is the final electron acceptor of cellular respiration.
When the protein gramicidin is integrated into a membrane, an H+ channel forms and the membrane becomes very permeable to protons (H+ ions). If gramicidin is added to an actively respiring muscle cell, how would it affect the rates of electron transport, proton pumping, and ATP synthesis in oxidative phosphorylation? (Assume that gramicidin does not affect the production of NADH and FADH2 during the early stages of cellular respiration.) Sort the labels into the correct bin according to the effect that gramicidin would have on each process.
Remains the same: proton pumping rate, electron transport rate, rate of oxygen uptake Decreases (or goes to zero): Rate of ATP synthesis, size of the proton gradient
In preparing pyruvate to enter the citric acid cycle, which of the following steps occurs? Pyruvate is oxidized and decarboxylated, and the removed electrons are used to reduce an NAD+ to an NADH. Pyruvate is reduced and decarboxylated, and the resulting electrons oxidize an NAD+ to an NADH Pyruvate is oxidized and decarboxylated, and the resulting electrons are donated to NADH to produce NAD+. Pyruvate is reduced to acetyl-coA, which involves the reduction of pyruvate, the addition of a carbon dioxide from the environment, and its reduction by NADH. Pyruvate is ionized directly to acetyl-coA.
Pyruvate is oxidized and decarboxylated, and the removed electrons are used to reduce an NAD+ to an NADH.
Among the products of glycolysis, which compounds contain energy that can be used by other biological reactions?
Pyruvate, NADH, ATP
Identify all correct statements about the basic function of fermentation. Select all that apply. The basic function of fermentation is the regeneration of NAD+, which allows continued ATP production by glycolysis. The basic function of fermentation is the production of additional ATP by further oxidation of the products of glycolysis. The basic function of fermentation is the production of ethyl alcohol or lactic acid.
The basic function of fermentation is the regeneration of NAD+, which allows continued ATP production by glycolysis.
In most cells, not all of the carbon compounds that participate in glycolysis and the citric acid cycle are converted to carbon dioxide by cellular respiration. What happens to the carbon in these compounds that does not end up as CO2?
The carbon compounds are removed from these processes to serve as building blocks for other complex molecules.
Which of the following statements about the chemiosmotic synthesis of ATP is correct?
The chemiosmotic synthesis of ATP requires that the electron transport in the inner mitochondrial membrane be coupled to proton transport across the same membrane.
What process occurs within Box B?
The citric acid cycle transfers electrons to NADH and FADH2.
Which statement about the citric acid cycle is correct?
The last reaction in the citric acid cycle produces a product that is a substrate for the first reaction of the citric acid cycle.
Which one of the following statements about the redox reactions of the electron transport chain is correct?
The redox reactions of the electron transport chain are directly coupled to the movement of protons across a membrane.
Which of these enters the citric acid cycle (also called the Krebs cycle)? a. G3P b. pyruvate c. glucose d. acetyl CoA e. NADH + H+
acetyl CoA
Which of these is NOT a product of the citric acid cycle (also called the Krebs cycle)? a. CO2 b. NADH + H+ c. FADH2 d. ATP e. acetyl CoA
acetyl CoA
Select Figure 2 (Figure 2) from the drop-down menu above the table to see a graphical version of the data. Which cell type(s) had the highest rate of oxygen consumption? cells from rats with low thyroid hormone cells from rats with normal thyroid hormone cells from rats with low or normal thyroid hormone
cells from rats with elevated thyroid hormone cells from rats with elevated thyroid hormone
Part A - Cellular respiration equation Drag the labels onto the equation to identify the inputs and outputs of cellular respiration.
from left to right it goes glucose-O2-CO2-H2O-ATP
Each of the four stages of cellular respiration occurs in a specific location inside or outside the mitochondria. These locations permit precise regulation and partitioning of cellular resources to optimize the utilization of cellular energy. Match each stage of cellular respiration with the cellular location in which it occurs. Labels may be used once, more than once, or not at all.
glycolysis -cytosol acetyl CoA formation - mitochondrial matrix citric acid cycle - mitochondrial matrix oxidative phosphorylation - inner mitochondrial membrane
If a compound that allows protons to freely diffuse across membranes is added to cells that are actively metabolizing glucose via cellular respiration, which of the following processes would stop? 1) glycolysis 2) electron transport 3) ATP synthesis 4) all of the above 5) none of the above
none of the above
What variable responded to thyroid hormone level (the independent variable), and what are the units for this variable? -temperature of rats, in degrees Celsius -oxygen consumption rate of liver cells, in nmol O2/min • mg cells -thyroid hormone level of the rats, in relative units -ATP production, in nmol ATP/min • mg cells
oxygen consumption rate of liver cells, in nmol O2/min • mg cells
In mitochondria, exergonic redox reactions __________. are the source of energy driving prokaryotic ATP synthesis provide the energy that establishes the proton gradient are directly coupled to substrate-level phosphorylation use ATP to pump H+ out of the mitochondrion reduce carbon atoms to carbon dioxide
provide the energy that establishes the proton gradient
In the citric acid cycle (also called the Krebs cycle), ATP molecules are produced by _____. a. cellular respiration b. photosynthesis c. photophosphorylation d. substrate-level phosphorylation e. oxidative phosphorylation
substrate-level phosphorylation
Which of the following is true for all exergonic reactions
the reaction proceeds with a net release of free energy
To see patterns in the data from an experiment like this, it is helpful to graph the data. A bar graph is used instead of a line graph because each type of liver cell was independent of the others. But first, you must determine which variable should go on each axis of the graph. What variable did the researchers intentionally vary in the experiment, and what are the units for this variable? genetic background of the rats chosen for the experiment, in type of breed thyroid hormone level of the rats chosen for the experiment, in relative units concentration of liver cells, in mg/mL oxygen consumption rate in liver cells, in nmol O2/min • mg cells
thyroid hormone level of the rats chosen for the experiment, in relative units
In mitochondrial electron transport, what is the direct role of O2?
to function as the final electron acceptor in the electron transport chain
Which of the following best describes the main purpose of the combined processes of glycolysis and cellular respiration?
transforming the energy in glucose and related molecules in a chemical form that cells can use for work
In the absence of oxygen, what is the net gain of ATP for each glucose molecule that enters glycolysis?
two ATP
The electrons stripped from glucose in cellular respiration end up in which compound?
water