Chapter 9
What kind of bond is formed when lithium and fluorine combine to form lithium fluoride?
ionic; The complete transfer of an electron from lithium to fluorine results in a stable compound in which both atoms have full outermost shells.
Once the electron donor in glycolysis gives up its electrons, it is oxidized to a compound called .
pyruvate
What is the oxidizing agent in the following reaction?Pyruvate + NADH + H+ → Lactate + NAD+
pyruvate
In fermentation _____ is reduced and _____ is oxidized.
pyruvate ... NADH
When a compound accepts (gains) electrons, that compound becomes reduced. Such a compound is often referred to as an electron acceptor.
reduced
In chemiosmosis, what is the most direct source of energy that is used to convert ADP +Pi to ATP?
energy released from movement of protons through ATP synthase, down their electrochemical gradient
In glycolysis, the carbon-containing compound that functions as the electron donor is glucose.
glucose
What happens to a glucose molecule when it loses a hydrogen atom as the result of an oxidation-reduction reaction?
he glucose molecule is oxidized.
Gaseous hydrogen burns in the presence of oxygen to form water:2H2 + O2 → 2H2 O + energyWhich molecule is oxidized and what kind of bond is formed?
hydrogen polar
How many carbons are in alpha-ketoglutarate?
5
How many carbons are in succinyl-coA?
5
How many carbons are in cis-aconitate?
6
How many carbons are in citrate?
6
How many carbons are in iso-citrate?
6
For each glucose that enters glycolysis, _____ NADH + H+ are produced by the citric acid cycle.
6
In glycolysis, as in all the stages of cellular respiration, the transfer of electrons from electron donors to electron acceptors plays a critical role in the overall conversion of the energy in foods to energy in ATP. These reactions involving electron transfers are known as oxidation-reduction, or redox, reactions.Drag the words on the left to the appropriate blanks on the right to complete the sentences.
1) Oxidized 2) Reduced 3) Glucose 4) Pyruvate 5) NAD⁺ 6) NADH
For each glucose that enters glycolysis, _____ acetyl CoA enter the citric acid cycle.
2
How many NADH are produced by glycolysis?
2
how many carbons in acetyl CoA
2
Starting with citrate, which of the following combinations of products would result from three acetyl CoA molecules entering the citric acid cycle?
3 ATP, 6 CO2, 9 NADH, and 3 FADH2
How many carbons are in Malate
4
How many carbons are in fumarate?
4
How many carbons are in succinate?
4
How many carbons in oxaloaceate
4
Approximately how much more free energy is supplied to the electron transport chain by NADH than by FADH2?
8 kcal/mol
Which of the following statements is not true of most cellular redox reactions?
A hydrogen atom is transferred to the atom that loses an electron.
In glycolysis, what starts the process of glucose oxidation?
ATP
Which statement correctly describes how this increased demand would lead to an increased rate of ATP production?
ATP level would fall at first, decreasing the inhibition of PFK and increasing the rate of ATP production
Which of these enters the citric acid cycle?
Acetyl CoA
Which terms describe two atoms when they form a bond in which electrons are completely transferred from one atom to the other?
Anion and cation.
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.
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.
If a mitochondrion ran out of molecular oxygen (O2), predict which of the following situations would occur in its electron transport chain.
FMN prosthetic groups would remain reduced and NADH would have nowhere to donate electrons.
Which term describes the degree to which an element attracts electrons?
Electronegativity.
FAD is reduced to
FADH2
Which of these is NOT a product of glycolysis?
FADH2
Of the following lists of electron transport compounds, which one lists them in order from the one containing electrons with the highest free energy to the one containing electrons with the lowest free energy? Note that not all electron transport compounds in the electron transport chain are listed.
FADH2 -- FMN of Complex I -- Fe-S of Complex II -- Q -- Fe-S of Complex III -- Cyt c -- Cyt a of Complex IV -- O2
Which statement best explains why more ATP is made per molecule of NADH than per molecule of FADH2?
Fewer protons are pumped across the inner mitochondrial membrane when FADH2 is the electron donor than when NADH is the electron donor.
What would happen to the cell's rate of glucose utilization?
Glucose utilization would increase a lot.
Cellular locations of the four stages of cellular respirationEach 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.
Glycolysis - CytosolAcetyl CoA - Mitochondrial matrix Citric acid cycle - Mitochondrial matrixOxidative phosphorylation - inner mitochondrial membrane
Under anaerobic conditions (a lack of oxygen), the conversion of pyruvate to acetyl CoA stops. Which of these statements is the correct explanation for this observation?
In the absence of oxygen, electron transport stops. NADH is no longer converted to NAD+, which is needed for the first three stages of cellular respiration.
is the compound that functions as the electron acceptor in glycolysis
NAD+
Which of the following statements about NAD+ is true?
NAD+ is reduced to NADH during glycolysis, pyruvate oxidation, and citric acid cycl
NAD+ is reduced to
NADH
The reduced form of the electron acceptor in glycolysis is
NADH
What is the correct order of electron transport compounds from best electron donor to best electron acceptor?
NADH -- Fe-S of Complex I -- Q -- Fe-S of Complex III -- Cyt c-- Cyt a of Complex IV -- O2
During electron transport, energy from _____ is used to pump hydrogen ions into the _____.
NADH and FADH2 ... intermembrane space
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⁺, GlucoseNet 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⁺, ADPNet Output: Coenzyme A, CO₂, NADH, ATPNot 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, O₂Net Output: NAD⁺, ATP, CO₂ and WaterNot Input or Output: Pyruvate, Glucose, Acetyl CoA, Coenzyme A and CO₂.
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, pyruvateNet Output: NADH, acetyl CoA, CO₂not input or output: O₂, ADP, glucose and ATP
Drag the terms on the left to the appropriate blanks on the right to complete the sentences.
O2 (molecular oxygen) is the final electron acceptor of the electron transport chain. Fe-S is a prosthetic group present in several components of the electron transport chain. NADH donates electrons to the electron transport chain. Complex III is a multi-protein complex within the electron transport chain. Q (ubiquinone) is a nonprotein organic electron carrier within the electron transport chain.
Which of the following statements is true of the bonds in a water molecule?
Oxygen holds electrons more tightly than hydrogen does, and the net charge is zero.
Among the products of glycolysis, which compounds contain energy that can be used by other biological reactions?
Pyruvate, NADH, ATP
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 uptakeDecreases (or goes to zero): Rate of ATP synthesis, size of the proton gradient
The proximate (immediate) source of energy for oxidative phosphorylation is _____.
The proximate (immediate) source of energy for oxidative phosphorylation is _____.
Which of these is NOT a product of the citric acid cycle?
acetyl CoA
In the oxidation of pyruvate to acetyl CoA, one carbon atom is released as CO2. However, the oxidation of the remaining two carbon atoms—in acetate—to CO2 requires a complex, eight-step pathway—the citric acid cycle. Consider four possible explanations for why the last two carbons in acetate are converted to CO2 in a complex cyclic pathway rather than through a simple, linear reaction. Use your knowledge of the first three stages of cellular respiration to determine which explanation is correct.
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.
In muscle cells, fermentation produces _____.
lactate and NAD+
Carbon dioxide (CO2) is released during which of the following stages of cellular respiration?
oxidation of pyruvate to acetyl CoA and the citric acid cycle
In cellular respiration, most ATP molecules are produced by _____.
oxidative phosphorylation
. When a compound donates (loses) electrons, that compound becomes oxidized. Such a compound is often referred to as an electron donor.
oxidized
The final electron acceptor of cellular respiration is _____.
oxygen
In glycolysis, ATP molecules are produced by _____.
substrate-level phosphorylation
In the citric acid cycle, ATP molecules are produced by _____.
substrate-level phosphorylation
Which of the following events takes place in the electron transport chain?
the harnessing of energy from high-energy electrons derived from glycolysis and the citric acid cycle
In mitochondrial electron transport, what is the direct role of O2?
to function as the final electron acceptor in the electron transport chain
In glycolysis there is a net gain of _____ ATP.
two
