Bio 150 LP Ch. 7
A simplified overall equation for respiration is as follows: C6H12O6 + 6O2 →6CO2+ 6H2O + energy In this reaction, we can say that _____ is reduced and _____ is oxidized.
oxygen; glucose
During which phase(s) of glycolysis do we observe pyruvate production, ATP synthesis, and reduction of NAD+?
payoff phase
Which process produces the highest number of reduced electron carriers and thus the greatest potential for generating ATP?
the citric acid cycle
In eukaryotes, fermentation takes place:
the cytoplasm
During the pyruvate oxidation stage of cellular respiration, which of the following occurs?
the formation of NADH, the oxidation of pyruvate, the formation of CO2, and the formation of acetyl-CoA
Which is the only reaction in the citric acid cycle that produces ATP by substrate-level phosphorylation?
the formation of succinate
We can tell from their structure that fatty acids are a good source of energy because of:
the large number of carbon-carbon and carbon-hydrogen bonds they contain
Which of the following is required for the preparatory phase of glycolysis and then produced during the payoff phase?
ATP
One of the enzymatic results of the pyruvate oxidation stage of cellular respiration is the reduction of _____to _____
NAD+; NADH
What product of the pyruvate oxidation stage of cellular respiration will have the two electrons that are lost from pyruvate?
NADH
Which of the following is an electron carrier in its reduced form?
NADH
In the cleavage phase of glycolysis:
a phosphorylated sugar molecule is broken apart and the products rearranged
In which organisms would you expect ethanol fermentation to occur?
fungi and plants
In cellular respiration, oxygen:
gains electrons and is reduced
Which of the following are inputs, but not outputs, of glycolysis?
glucose
The storage carbohydrate in animals is ___________ and in plants is _________
glycogen; starch
The breakdown of fatty acids takes place by a process called:
beta-oxidation
Cellular respiration is a series of _____ reactions.
catabolic
In eukaryotic cells, glycolysis occurs in:
cytoplasm
During what phase of glycolysis is NADH formed?
during phase 3, when glyceraldehyde 3-phosphate is phosphorylated
During glycolysis, pyruvate oxidation, and the citric acid cycle, the chemical energy in glucose is transferred to:
electron carriers and ATP
Tracing the metabolism of one glucose molecule, how many carbon atoms are fully oxidized to CO2 at the completion of glycolysis?
0
Oxidative phosphorylation yields _____ ATP for each molecule of FADH2 that is oxidized, whereas it yields _____ ATP for each molecule of NADH.
1.5;2.5
Which of the following is a net product of glycolysis?
2 pyruvate
Tracing the metabolism of one glucose molecule, how many carbon atoms are fully oxidized to CO2 at the completion of aerobic respiration?
6
Which best describes energy captured in ATP during aerobic cellular respiration?
A small amount of energy is captured in ATP by substrate-level phosphorylation; most is captured in ATP by oxidative phosphorylation
During a long bout of sustained exercise, in which order will your body's energy stores/sources be used?
ATP stored in muscle, glycogen stored in muscle, glycogen stored in the liver, fatty acids
The ethanol resulting from fermentation of glucose only accounts for four of the six starting carbon atoms. In which of the following are the other two carbon atoms found?
CO2
What is the fully oxidized product that results from the pyruvate oxidation stage of cellular respiration?
CO2
What happens when glucose is phosphorylated during phase 1 of glycolysis?
Glucose is destabilized so that it can be broken apart in phase 2
You may be familiar with the story of Philippides, the famous Greek runner who ran the first marathon and then died after completing his run. Based on what you know of aerobic respiration and fermentation, why might Philippides have died?
His muscles may have produced toxic levels of lactic acid, causing his blood to become more acidic
During the citric acid cycle, which is shown, what happens to the coenzyme A that is part of acetyl-CoA?
It is recycled for use in other reactions
Which best describes how ATP synthase converts the potential energy of the proton gradient to the chemical energy of ATP?
Kinetic energy from the flow of protons is converted to the kinetic energy of rotation of the Fosubunit; the rotation of the Fo subunit leads to rotation of the F1 subunit, which can then catalyze ATP synthesis
Which statement is true regarding pyruvate and glucose?
Pyruvate can be transported across both membranes of the mitochondrion to be further metabolized, but glucose cannot
A researcher is comparing the amount of protein contained in inner and outer mitochondrial membranes. What do you predict they will find?
The amount of proteins will be greater in the inner membrane
Glycolysis is:
anaerobic
Lactic acid fermentation occurs in
bacteria and animals
The first phase of glycolysis requires the input of two ATP molecules. It is therefore:
endergonic
Fermentation occurs only in anaerobic conditions
false
Fermentation produces nearly twice as much ATP as aerobic respiration, which explains why it is a preferred pathway for bacteria.
false
In a plant cell, the oxidative phosphorylation stage of cellular respiration is carried out in the cytoplasm.
false
Malate is both the starting and ending product of the citric acid cycle.
false
Oxidation is the gain of electrons.
false
The glycolysis stage is responsible for producing most of the ATP during cellular respiration.
false
The majority of cells within the human body have a very high baseline amount of ATP, so cells are always prepared for any long-term activity.
false
Which of the following is one explanation for why glycolysis is believed to have arisen very early in the evolution of life?
it does not require oxygen
Pyruvate oxidation is an important stage in cellular respiration because:
it links glycolysis with the citric acid cycle
When a substance in a reaction is oxidized, it:
loses electrons
The chemical bonds of carbohydrates and lipids have high potential energy because:
many of these bonds are C—C and C—H bonds, in which electrons are shared equally between atoms
In eukaryotes, pyruvate oxidation takes place in the
mitochondrial matrix
In eukaryotes, pyruvate oxidation takes place in the:
mitochondrial matrix
In what organelle is pyruvate oxidation carried out in a cell?
mitochondrion
The citric acid cycle is a cycle because the starting molecule, _____, is regenerated at the end.
oxaloacetate
The loss of electrons is referred to as:
oxidation
The mitochondrial electron transport chain is part of:
oxidative phosphorylation
Which stages of cellular respiration use O2 as an input?
oxidative phosphorylation
A molecule that is _____ loses electrons, and a molecule that is _____ gains electrons.
oxidized; reduced
In cellular respiration, glucose is _____ to CO2 and oxygen is _____ to water.
oxidized; reduced
The final (terminal) electron acceptor of the electron transport chain is:
oxygen
Acetyl-CoA synthesis occurs during:
pyruvate oxidation
Which stage of cellular respiration occurs following production of pyruvate?
pyruvate oxidation
When you exhale, there is more CO2 than was present in the air that you inhaled. This CO2 comes from reactions in:
pyruvate oxidation and the citric acid cycle
Which stages of cellular respiration produce CO2 as a waste product?
pyruvate oxidation and the citric acid cycle
Which statement is true regarding pyruvate oxidation?
pyruvate oxidation forms the same number of NADH (per glucose molecule) as glycolysis
In pyruvate oxidation, the electron donor is _____ and the electron acceptor is _____.
pyruvate; NAD+
At the end of glycolysis, the carbon originally found in the starting glucose molecule is now present in:
two pyruvate molecules
The _____ forms of the electron carriers NAD+/NADH and FAD/FADH2 have high potential energy.
reduced
In glycolysis, ATP is synthesized by:
substrate-level phosphorylation
Coenzyme Q and cytochrome c:
transfer electrons between protein complexes of the electron transport chain
In addition to destabilizing glucose for subsequent breakdown, what else does phosphorylation of glucose do?
traps glucose inside the cell
Both NAD+ and molecular oxygen serve as electron acceptors in cellular respiration
true
Conditions that reduce the strength of the proton gradient across the inner mitochondrial membrane slow the production of ATP by ATP synthase.
true
The ATP produced during glycolysis is the result of substrate-level phosphorylation.
true
When glucose is broken down in a cell, all of the energy it stores is not released simultaneously but is instead released in a stepwise process.
true
Although glycolysis produces four molecules of ATP by substrate-level phosphorylation, the net gain of ATP for the cell is two molecules. This is because:
two molecules are used in the initial stage
Which of the following summarizes the net final products of glycolysis?
two molecules of pyruvate, two molecules of ATP, and two molecules of NADH
Of the 6 carbons in a starting molecule of glucose, at the completion of pyruvate oxidation, _____ carbons are fully oxidized to _____, while _____ carbons remain in _____. Please choose the correct answer from the following choices, and then select the submit answer button.
two; CO2; four; acetyl groups
Which of the following is a product (as opposed to a substrate) of at least one of the processes of cellular respiration?
water
