Final Exam
When a person is sprinting, the person\'s muscle cells will begin using anaerobic respiration in addition to keeping the mitochondria respiring aerobically as much as the oxygen supply will allow. What benefits do muscle cells gain from anaerobic respiration in this situation?
-For every glucose molecule that enters glycolysis, the cell generates, without oxygen, two ATP molecules that can keep the muscles moving. -Adding electrons from NADH to pyruvate regenerates NAD , so that glycolysis can continue, and produces lactic acid, a waste product that can diffuse out of the cell.
Each acetyl CoA produces _____ ATP in the citric acid cycle.
12
When combined with the electron transport chain, one turn of the citric acid cycle produces _____ ATP.
12
How many carbon atoms are fed into the citric acid cycle as a result of the oxidation of one mol of pyruvate?
2
The net energy production in anaerobic glycolysis is _____.
2 atp
Starting with one molecule of glucose, the energy-containing products of glycolysis are?
2NADH, 2 pyruvate, and 2 ATP
Each of the two pyruvate produced during glycolysis has ___ carbons
3
Which of the three major stages of metabolism includes the citric acid cycle?
3
C6H12O6+6CO2----->6CO2+____ATP+6H2O
36
The complete oxidation of glucose produces _____ ATP molecules.
36
What happens at the end of the chain in the electron transport chain?
4 electrons combine with a molecule of oxygen and 4 protons
conversion of 1 molecule of pyruvate to 3 molecules CO2 via the intermediate reaction & CAC also yields ___ molecules of NADH, __ molecule of FADH2, and ___ molecules of ATP or GTP.
4; 1; 1
How many O2 molecules are required each time a molecule of glucose is completely oxidized to CO2 and water via aerobic respiration?
6
In glycolysis, glucose produces 2 pyruvate molecules and a total of _____ ATP molecules.
6
Approx. how many molecules of ATP are produced from the complete oxidation of 2 molecules of glucose (C6H12O6) in cellular respiration?
72
The passage of H+ ions through ________ causes it to spin and produce AT
ATP Synthase
Most efficient biological energy producing process is
Aerobic Respiration
This describes a process that does NOT require oxygen; it means "without air"
Anaerobic
Which of the following compounds in the citric acid cycle undergoes oxidative decarboxylation? A) citrate B) isocitrate C) succinate D) fumarate E) succinyl CoA
B
Primary function of the mitochondria is the production of ATP. To carry out this function, the mitochondria must have all of the following except: A. proton pumps embedding in the inner membrane B. enzymes for the CAC membrane C. enzymes for glycolysis D. membrane-count electron transport chain E. mitochondrial ATP synthase
C
Inside an active mitochondrion most electrons follow which pathway
CAC---> NADH ----> ETC ------> O2
The carbon atoms in pyruvic acid end up as ___ in the atmosphere following the Krebs cycle.
CO2
In the absence of O2, yeast cells can obtain energy by fermentation resulting in the production of?
CO2 and ethanol
What is the term for metabolic pathways that release stored energy by breaking down complex molecules?
Catabolic Pathways
This molecule reacts with pyruvic acid to release C02, produce NADH, and acetyl-CoA.
Coenzyme A
Which electron transport chain or oxidative phosphorylation complex is directly responsible for the reduction of O2 to H2O? In other words this complex transfers electrons to O2 and form H2O once it has combined with H+ ions.
Complex 4
Which of the protein complexes will transfer electrons to O2?
Complex 4
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. glyceraldehyde-3-phosphate C. oxaloacetate D. acetyl CoA E. citrate
D
The NADH and FADH2 produced during the Krebs cycle pass their electrons down the __________________ chain to produce ATP.
Electron Transport
In the dehydrogenation of succinate to fumarate in the citric acid cycle, the coenzyme used is
FAD
During aerobic respiration, what directly donates electrons to the electron transport chain at the lowest energy level?
FADH2
The electron carrier ____ provides 2 ATP via the electron transport chain
FADH2
The electron carrier _____ provides two ATP via the electron transport chain.
FADH2
_______ is the storage form of glucose used by animal cells which can be broken down for energy when glucose is used up.
Glycogen
The immediate energy source that drives ATP synthesis by ATP synthase during oxidative phosphorylation is the?
H+ concentration across the membrane holding ATP synthase.
Which of the following are the final products of the electron transport chain and oxidative phosphorylation?
H2O, NAD+, ATP, FAD
As electrons pass down the electron transport chain, H+ ions build up in the
Intermembrane Space
Complex 2 differed from the other three complexes of the ETC. How?
It doesn't pump protons.
An enzyme catalyzes a reaction in a way that results in a lower activation energy. What is the significance of a lower activation energy?
It increases the rate of a cellular reaction.
The ____ cycle breaks down pyruvic acid into carbon dioxide and produces NADH, FADH2, and ATP.
Krebs
Type of fermentation used by human muscles in low oxygen conditions and microorganisms to make yogurt, cheese, pickles, sauerkraut and kimchi
Lactic Acid
During aerobic respiration, H2O is formed. Where does the oxygen atom for the formation of water come from?
Molecular Oxygen
What electron acceptor(s) is(are) used in the citric acid cycle?
NAD+ + FAD
Most of the energy released in the citric acid cycle is used to produce
NADH and FADH2.
In addition to ATP, what are the end products of glycolysis?
NADH and pyruvate
Hydrogen ion concentration is higher in the intermembrane space than in the mitochondrial matrix.
T
Hydrogen ions are actively transported out of the mitochondrial matrix.
T
Oxidative phosphorylation relies on the hydrogen ion concentration gradient generated and maintained by the electron transport chain.
T
The NADH produced in glycolysis must be oxidized to NAD+ because the NAD+ is essential for glycolysis to proceed.
TRUE
NAD+ participates in reactions that produce
a C=O bond.
In biochemical systems, the term reduction often refers
a gain of hydrogen or electrons by a compound.
In CR, the energy for most ATP synthesis is supplied by
a proton gradient across a membrane
The oxygen consumed during cellular respiration is involved directly in which process or event?
accepting electrons at the end of the ETC
Pyruvate+CoA+NAD+ ------->
acetyl CoA + NADH+H+ + CO2
The middle stage of catabolism is the point at which
acetyl CoA is produced
44) When oxygen is in plentiful supply in the cell, pyruvate is converted to
acetyl CoA.
Under aerobic conditions, pyruvate produced in glycolysis can be converted to
acetyl coA
_____ forms when Coenzyme A attaches to two carbons from pyruvic acid
acetyl coA
Citric acid cycle: step 2 citrate = isocitrate
aconitase
Primary role of oxygen in CR is to
act as an acceptor for electrons and hydrogen, forming water
Coenzyme A is a molecule whose function is to
activate acyl groups for reaction.
The components of ATP are
adenine, ribose, and triphosphate
Type of fermentation used to make bread dough rise and produce beer and wine.
alcoholic
Citric acid cycle: step 4 alpha ketoglutarate -> succinyl-CoA
alpha ketoglutarate dehydrogenase
In stage three of metabolism, the overall result is to release
carbon dioxide and energy.
The final products of catabolic reactions are
carbon dioxide, water, and ammonia.
Citric acid cycle: step 1 AcetylCoA -> citrate
citrate synthase
the folded inner membranes inside a mitochondrion are called
cristae
Where does glycolysis take place in cells?
cytosol
In stage 1 of metabolism what occurs?
digestion of large molecules
In the electron transport chain, NADH and FADH2 are used to provide
electrons and hydrogen ions.
In chemiosmothic phosphorylation, 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 the electrochemical gradient
increase the rate of a reaction by lowering the activation energy barrier.
enzymes
The hydrolysis of ATP to ADP is
exothermic
If oxygen is NOT present, glycolysis is followed by
fermentation
When hydrogen ions are pumped from the mitochondrial matrix across the inner membrane and into the inter membrane space, the result is the?
formation of ATP
FAD is a coenzyme which usually participates in
formation of carbon-carbon double bonds.
Citric acid cycle: step 7 fumerate = malate
fumerase
This molecule has the formula C6H12O6 and is split in half during glycolysis
glucose
The citric acid cycle is used in the oxidation of
glucose, fatty acids, and proteins.
Which metabolic pathway is common to both cellular respiration and fermentation?
glycolysis
Which metabolic pathway is common to both fermentation and CR of a glucose molecule?
glycolysis
Which of the following normally occurs regardless of whether or not oxygen is present?
glycolysis
Which of the following occurs in the cytosol of a eukaryotic cell?
glycolysis and fermentation
NAD+ is reduced to NADH during..
glycolysis, pyruvate oxidation, and the CAC
In step 7 of the citric acid cycle, fumarate is converted to malate by a _____ reaction.
hydration
Aerobic resynthesis of ATP occurs:
in the mitochondria in a process called oxidative phosphorylation
Where is ATP synthase located in the mitochondria?
inner membrane
Citric acid cycle: step 3 isocitrate -> alpha ketoglutarate
isocitrate dehydrogenase
Fatty acids and glycerol are produced from the metabolism of
lipids
Citric acid cycle: step 8 malate = oxaloacetate
malate dehydrogenase
The area inside the cristae where the Krebs cycle happens is the
matrix
Cell organelle which acts as the cell's power plant to burn glucose and store energy as ATP
mitochondria
Where are the proteins of the electron transport chain located?
mitochondrial inner membrane
Energy released by the ETC is used to pump H+ into which location in eukaryotic cells?
mitochondrial inter membrane space
The ultimate electron acceptor in the fermentation of glucose to ethanol is:
nad+
A substance loses electrons (and amount of positive charge is increased)
oxidation
CO2 is released during which of the following stages of cellular respiration?
oxidation of pyruvate and acetyl CoA and the CAC
The CAC step that removes the first CO2 molecule is a reaction
oxidative decarboxylation
The citric acid cycle step that removes the first CO2 molecule is a(n)
oxidative decarboxylation.
Which of the following produces the most ATP when glucose is completely oxidized to CO2 and H2O?
oxidative phosphorylation (chemiosmosis)
In the electron transport chain, the synthesis of ATP from ADP + Pi is called
oxidative phosphorylation.
When a glucose molecule loses a hydrogen atom as the result of an oxidation-reduction reaction, the molecule becomes?
oxidized
The final electron acceptor of the ETC that functions in aerobic oxidative phosphorylation is?
oxygen
This atmospheric gas is required for aerobic respiration
oxygen
This 3 carbon molecule is produced during glycolysis when glucose splits in half
pyruvic acid
molecule of NAD+ gains a hydrogen atom (not a proton), it becomes?
reduced
gains electrons
reduction
During glycolysis, when each mol of glucose is catabolized to 2 molecules of pyruvate, most of the potential energy contained in glucose is?
retained in the two pyruvate
In step 7 of glycolysis, ATP is generated when a phosphate group is transferred directly from
substrate level phosphorylation
The ATP made during glycolysis is generated by?
substrate level-phosphorylation
Citric acid cycle: step 6 succinate = fumerate
succinate dehydrogenase
Citric acid cycle: step 5 succinyl-CoA = succinate
succinyl-CoA synthetase
Under aerobic conditions, pyruvate is completely oxidized to CO2 and H2O.
t
Most CO2 from catabolism is released during?
the CAC
The citric acid cycle operates only under aerobic conditions because..
the NADH and FADH2 produced by the CAC can only be reoxidizes by the electron transport chain
In the absence of O2 how is the NADH formed in glycolysis recycled to form NAD+?
the NADH is oxidized as pyruvate is reduced to lactate
What is proton-motive force?
the force exerted on a proton by a transmembrane proton concentration gradient
When electrons flow along the ETC of mitochondria, which of the following changes occurs?
the pH of the matrix increases
The direct energy source that drives ATP synthesis during respiratory oxidative phosphorylation in eukaryotic cells is?
the proton-motive force across the inner mitochondrial membrane
Overall, one turn of the citric acid cycle produces
three NADH molecules.
In glycolysis, for each molecule of glucose oxidized to pyruvate
two molecules of ATP are used and four molecules of ATP are produced. NET OF 2
Why is glycolysis described as having an investment phase and a payoff phase?
uses stored ATP and then forms a net increase in ATP
