ch 8
what happens in energy payoff phase of glycolysis
-exergonic release of ATP -NADH takes hydrogen from G3P in reduction -G3P oxidized (bc reduction)
Pyruvate oxidation to acetyl CoH two parts
1. pyruvate: diffuses through small pores into outer membrane Active transport: into inner membrane 2. Pyruvate dehydrogenase: remove carboxyl via oxidative= Co2 released
which carriers use energy to pump hydrogens from matrix across inner membrane
1, 3, 4
Glycolysis parts 2
a. Energy phase b. energy payoff phase
what role does oxygen play in chemiosmosis
electron acceptor
cellular respiration steps 1-4 & accronym
Glycolysis-GOOD Pyruvate oxidation to acetyl CoH-PUGS Citric acid cycle- Called Oxidative phosphorylation- Ollie
Flow of energy through environment
Sunlight, digestive system, cellular respiration
How many carbon atoms are fed into the citric acid cycle as a result of the oxidation of one molecule of pyruvate? A) 2 B) 4 C) 6 D) 8 E) 10
a
In alcohol fermentation, NAD+ is regenerated from NADH during which of the following? A) reduction of acetaldehyde to ethanol (ethyl alcohol) B) oxidation of pyruvate to acetyl CoA C) reduction of pyruvate to form lactate D) oxidation of NAD+ in the citric acid cycle E) phosphorylation of ADP to form ATP
a
The final electron acceptor of the electron transport chain that functions in aerobic oxidative phosphorylation is A) oxygen. B) water. C) NAD+. D) pyruvate. E) ADP.
a
When electrons flow along the electron transport chains of mitochondria, which of the following changes occurs? A) The pH of the matrix increases. B) ATP synthase pumps protons by active transport. C) The electrons gain free energy. D) The cytochromes phosphorylate ADP to form ATP. E) NAD+ is oxidized.
a
Which of the following normally occurs whether or not oxygen (O2) is present? A) glycolysis B) fermentation C) oxidation of pyruvate to acetyl CoA D) citric acid cycle E) oxidative phosphorylation (chemiosmosis)
a
An electron loses potential energy when it A) shifts to a less electronegative atom. B) shifts to a more electronegative atom. C) increases its kinetic energy. D) increases its activity as an oxidizing agent. E) attaches itself to NAD+.
b
Carbon dioxide (CO2) is released during which of the following stages of cellular respiration? A) glycolysis and the oxidation of pyruvate to acetyl CoA B) oxidation of pyruvate to acetyl CoA and the citric acid cycle C) the citric acid cycle and oxidative phosphorylation D) oxidative phosphorylation and fermentation E) fermentation and glycolysis
b
Most CO2 from catabolism is released during A) glycolysis. B) the citric acid cycle. C) lactate fermentation. D) electron transport. E) oxidative phosphorylation.
b
How does pyruvate enter the mitochondrion? A) active transport B) diffusion C) facilitated diffusion D) through a channel E) through a pore
c
where does glycolysis occur
cytosol
Which metabolic pathway is common to both cellular respiration and fermentation? A) the oxidation of pyruvate to acetyl CoA B) the citric acid cycle C) oxidative phosphorylation D) glycolysis E) chemiosmosis
d
Substrate-level phosphorylation accounts for approximately what percentage of the ATP formed during glycolysis? A) 0% B) 2% C) 10% D) 38% E) 100%
e
what breaks down glucose and forms pyruvate from 2 ATPS
glycolysis
how glucose relates to flow of energy
in most cells which creates energy
where does chemiosmosis occur
inner mitochondria membrane
result of chemiosmosis
oxgen is reduced
which part of cellular respiration releases co2
pyruvate oxidation
The ATP made during glycolysis is generated by A) substrate-level phosphorylation. B) electron transport. C) photophosphorylation. D) chemiosmosis. E) oxidation of NADH to NAD+.
a
electron transport function in oxidative phosphorlyation
transfer NADH+FADH+ to oxygen
what happens in energy phase of glycolysis
used 2 ATP to make 2 G3P
During glycolysis, when glucose is catabolized to pyruvate, most of the energy of glucose is A) transferred to ADP, forming ATP. B) transferred directly to ATP. C) retained in the pyruvate. D) stored in the NADH produced. E) used to phosphorylate fructose to form fructose-6-phosphate.
c
During oxidative phosphorylation, H2O is formed. Where does the oxygen for the synthesis of the water come from? A) carbon dioxide (CO2) B) glucose (C6H12O6) C) molecular oxygen (O2) D) pyruvate (C3H3O3-) E) lactate (C3H5O3-)
c
How many molecules of carbon dioxide (CO2) would be produced by five turns of the citric acid cycle? A) 2 B) 5 C) 10 D) 12 E) 60
c
In addition to ATP, what are the end products of glycolysis? A) CO2 and H2O B) CO2 and pyruvate C) NADH and pyruvate D) CO2 and NADH E) H2O, FADH2, and citrate
c
One function of both alcohol fermentation and lactic acid fermentation is to A) reduce NAD+ to NADH. B) reduce FAD+ to FADH2. C) oxidize NADH to NAD+. D) reduce FADH2 to FAD+. E) none of the above
c
When a glucose molecule loses a hydrogen atom as the result of an oxidation-reduction reaction, the molecule becomes A) dehydrogenated. B) hydrogenated. C) oxidized. D) reduced. E) an oxidizing agent.
c
When a molecule of NAD+ (nicotinamide adenine dinucleotide) gains a hydrogen atom (not a hydrogen ion) the molecule becomes A) hydrogenated. B) oxidized. C) reduced. D) redoxed. E) a reducing agent.
c
Where are the proteins of the electron transport chain located? A) cytosol B) mitochondrial outer membrane C) mitochondrial inner membrane D) mitochondrial intermembrane space E) mitochondrial matrix
c
Where do the catabolic products of fatty acid breakdown enter into the citric acid cycle? A) pyruvate B) malate or fumarate C) acetyl CoA D) -ketoglutarate E) succinyl CoA
c
During aerobic respiration, which of the following directly donates electrons to the electron transport chain at the lowest energy level? A) NAD+ B) NADH C) ATP D) ADP + Pi E) FADH2
e
During cellular respiration, acetyl CoA accumulates in which location? A) cytosol B) mitochondrial outer membrane C) mitochondrial inner membrane D) mitochondrial intermembrane space E) mitochondrial matrix
e
What is the purpose of beta oxidation in respiration? A) oxidation of glucose B) oxidation of pyruvate C) feedback regulation D) control of ATP accumulation E) breakdown of fatty acids
e
When electrons move closer to a more electronegative atom, what happens? A) Energy is released. B) Energy is consumed. C) The more electronegative atom is reduced. D) The more electronegative atom is oxidized. E) A and C are correct.
e
Where does glycolysis takes place? A) mitochondrial matrix B) mitochondrial outer membrane C) mitochondrial inner membrane D) mitochondrial intermembrane space E) cytosol
e
Which of the following produces the most ATP when glucose (C6H12O6) is completely oxidized to carbon dioxide (CO2) and water? A) glycolysis B) fermentation C) oxidation of pyruvate to acetyl CoA D) citric acid cycle E) oxidative phosphorylation (chemiosmosis)
e
outcome of Pyruvate oxidation to acetyl CoH
2 pyruvates,, 2 NADs, 2 Co2
Which of the following occurs in the cytosol of a eukaryotic cell? A) glycolysis and fermentation B) fermentation and chemiosmosis C) oxidation of pyruvate to acetyl CoA D) citric acid cycle E) oxidative phosphorylation
a
Which of the following statements describes NAD+? A) NAD+ is reduced to NADH during both glycolysis and the citric acid cycle. B) NAD+ has more chemical energy than NADH. C) NAD+ is reduced by the action of hydrogenases. D) NAD+ can donate electrons for use in oxidative phosphorylation. E) In the absence of NAD+, glycolysis can still function.
a
Which of the following statements describes the results of this reaction? C6H12O6 + 6 O2 → 6 CO2 + 6 H2O + Energy A) C6H12O6 is oxidized and O2 is reduced. B) O2 is oxidized and H2O is reduced. C) CO2 is reduced and O2 is oxidized. D) C6H12O6 is reduced and CO2 is oxidized. E) O2 is reduced and CO2 is oxidized.
a
During aerobic respiration, electrons travel downhill in which sequence? A) food → citric acid cycle → ATP → NAD+ B) food → NADH → electron transport chain → oxygen C) glucose → pyruvate → ATP → oxygen D) glucose → ATP → electron transport chain → NADH E) food → glycolysis → citric acid cycle → NADH → ATP
b
In glycolysis, for each molecule of glucose oxidized to pyruvate A) 2 molecules of ATP are used and 2 molecules of ATP are produced. B) 2 molecules of ATP are used and 4 molecules of ATP are produced. C) 4 molecules of ATP are used and 2 molecules of ATP are produced. D) 2 molecules of ATP are used and 6 molecules of ATP are produced. E) 6 molecules of ATP are used and 6 molecules of ATP are produced.
b
Starting with one molecule of glucose, the ʺnetʺ products of glycolysis are A) 2 NAD+, 2 H+, 2 pyruvate, 2 ATP, and 2 H2O. B) 2 NADH, 2 H+, 2 pyruvate, 2 ATP, and 2 H2O. C) 2 FADH2, 2 pyruvate, 4 ATP, and 2 H2O. D) 6 CO2, 6 H2O, 2 ATP, and 2 pyruvate. E) 6 CO2, 6 H2O, 36 ATP, and 2 citrate.
b
The ATP made during fermentation is generated by which of the following? A) the electron transport chain B) substrate-level phosphorylation C) chemiosmosis D) oxidative phosphorylation E) aerobic respiration
b
The molecule that functions as the reducing agent (electron donor) in a redox or oxidation-reduction reaction A) gains electrons and gains energy. B) loses electrons and loses energy. C) gains electrons and loses energy. D) loses electrons and gains energy. E) neither gains nor loses electrons, but gains or loses energy.
b
The oxygen consumed during cellular respiration is involved directly in which process or event? A) glycolysis B) accepting electrons at the end of the electron transport chain C) the citric acid cycle D) the oxidation of pyruvate to acetyl CoA E) the phosphorylation of ADP to form ATP
b
The primary role of oxygen in cellular respiration is to A) yield energy in the form of ATP as it is passed down the respiratory chain. B) act as an acceptor for electrons and hydrogen, forming water. C) combine with carbon, forming CO2. D) combine with lactate, forming pyruvate. E) catalyze the reactions of glycolysis.
b
What is the reducing agent in the following reaction? Pyruvate + NADH + H+ Lactate + NAD+ A) oxygen B) NADH C) NAD+ D) lactate E) pyruvate
b
What is the term for metabolic pathways that release stored energy by breaking down complex molecules? A) anabolic pathways B) catabolic pathways C) fermentation pathways D) thermodynamic pathways E) bioenergetic pathways
b
When muscle cells are oxygen deprived, the heart still pumps. What must the heart cells be able to do? A) derive sufficient energy from fermentation B) continue aerobic metabolism when skeletal muscle cannot C) transform lactate to pyruvate again D) remove lactate from the blood E) remove oxygen from lactate
b
Which of the following is a true distinction between fermentation and cellular respiration? A) Only respiration oxidizes glucose. B) NADH is oxidized by the electron transport chain in respiration only. C) Fermentation, but not respiration, is an example of a catabolic pathway. D) Substrate-level phosphorylation is unique to fermentation. E) NAD+ functions as an oxidizing agent only in respiration.
b
Which process in eukaryotic cells will proceed normally whether oxygen (O2) is present or absent? A) electron transport B) glycolysis C) the citric acid cycle D) oxidative phosphorylation E) chemiosmosis
b
Why does the oxidation of organic compounds by molecular oxygen to produce CO2 and water release free energy? A) The covalent bonds in organic molecules are higher energy bonds than those in water and carbon dioxide. B) Electrons are being moved from atoms that have a lower affinity for electrons (such as C) to atoms with a higher affinity for electrons (such as O). C) The oxidation of organic compounds can be used to make ATP. D) The electrons have a higher potential energy when associated with water and CO 2 than they do in organic compounds. E) The covalent bond in O2 is unstable and easily broken by electrons from organic molecules.
b
Why is glycolysis considered to be one of the first metabolic pathways to have evolved? A) It produces much less ATP than does oxidative phosphorylation. B) It is found in the cytosol, does not involve oxygen, and is present in most organisms. C) It is found in prokaryotic cells but not in eukaryotic cells. D) It relies on chemiosmosis which is a metabolic mechanism present only in the first cells-prokaryotic cells. E) It requires the presence of membrane-enclosed cell organelles found only in eukaryotic cells.
b
how digestive system relates to flow of energy
break down food, sugars, proteins, fatty acids
glycolysis
breaks down glucose and forms pyruvate from 2 ATPS
he immediate energy source that drives ATP synthesis by ATP synthase during oxidative phosphorylation is A) the oxidation of glucose and other organic compounds. B) the flow of electrons down the electron transport chain. C) the affinity of oxygen for electrons. D) the H+ concentration gradient across the inner mitochondrial membrane. E) the transfer of phosphate to ADP.
c
n mitochondria, exergonic redox reactions A) are the source of energy driving prokaryotic ATP synthesis. B) are directly coupled to substrate-level phosphorylation. C) provide the energy that establishes the proton gradient. D) reduce carbon atoms to carbon dioxide. E) are coupled via phosphorylated intermediates to endergonic processes.
c
4 carriers in the electron transport during oxidative phosphorylation:
carrier 1: accept electron from NADH, transfers to FADH Carrier 2: accept electron from FADH, transfers to Q carrier 3: accepts electron from Q, transfers to C carrier 4: accepts electron from C, reduces O2 to H2O
citric acid cycle
chemical reactions used to release stored energy through oxidation
explains coupling of transport with ATP synthesis in aerobic respiration
chemiosmosis
what step of cellular respiration is glucose completely oxidized
citric acid cycle
how cellular respiration relates to flow of energy
converts stored energy into nutrients, anaerobic: catabolize nutrients=energy
A molecule that is phosphorylated A) has been reduced as a result of a redox reaction involving the loss of an inorganic phosphate. B) has a decreased chemical reactivity; it is less likely to provide energy for cellular work. C) has been oxidized as a result of a redox reaction involving the gain of an inorganic phosphate. D) has an increased chemical reactivity; it is primed to do cellular work. E) has less energy than before its phosphorylation and therefore less energy for cellular work.
d
Energy released by the electron transport chain is used to pump H + ions into which location? A) cytosol B) mitochondrial outer membrane C) mitochondrial inner membrane D) mitochondrial intermembrane space E) mitochondrial matrix
d
Where is ATP synthase located in the mitochondrion? A) cytosol B) electron transport chain C) outer membrane D) inner membrane E) mitochondrial matrix
d
Which of the following intermediary metabolites enters the citric acid cycle and is formed, in part, by the removal of a carbon (CO2) from one molecule of pyruvate? A) lactate B) glyceraldehydes-3-phosphate C) oxaloacetate D) acetyl CoA E) citrate
d
Why are carbohydrates and fats considered high energy foods? A) They have a lot of oxygen atoms. B) They have no nitrogen in their makeup. C) They can have very long carbon skeletons. D) They have a lot of electrons associated with hydrogen. E) They are easily reduced.
d
cells do not catabolize carbon dioxide because A) its double bonds are too stable to be broken. B) CO2 has fewer bonding electrons than other organic compounds. C) CO2 is already completely reduced. D) CO2 is already completely oxidized. E) the molecule has too few atoms.
d
he immediate energy source that drives ATP synthesis by ATP synthase during oxidative phosphorylation is A) the oxidation of glucose and other organic compounds. B) the flow of electrons down the electron transport chain. C) the affinity of oxygen for electrons. D) the H+ concentration gradient across the inner mitochondrial membrane. E) the transfer of phosphate to ADP.
d
Why is glycolysis described as having an investment phase and a payoff phase? A) It both splits molecules and assembles molecules. B) It attaches and detaches phosphate groups. C) It uses glucose and generates pyruvate. D) It shifts molecules from cytosol to mitochondrion. E) It uses stored ATP and then forms a net increase in ATP.
e
2 parts of oxidative phosphorylation
electron transport and chemiosmosis
where is majority of ATP produced
electron transport and chemiosmosis
where does citric acid cycle occur
matrix of mitochondria
where does Pyruvate oxidation to acetyl CoH occur
mitochondria
how sunlight related to flow of energy
sun=energy