chapter 7: cellular respiration
Select the products yielded by the passage of glucose through glycolysis and the citric acid cycle.
- ATP -NADH -CO2
Select the events that occur in the reaction that produces acetyl-CoA
- CO2 is removed from pyruvate - an acetyl group is attached to coenzyme A (CoA) - NAD+ is reduced
which of the following are end products of glycolysis
- NADH - Pyruvate - ATP
Place the membrane complexes and electron carriers in the order that electrons encounter them in the electron transport chain beginning with the first protein to receive the electron
- NADH dehydrogenase -ubiquinone - bc1 complex -cytochrome c - cytochrome oxidase complex
Select the true statements about the first half of glycolysis (priming and cleavage reactions).
- a 6c molecule is split to form two 3 carbon molecules - ATP is used
Of the following choices, which are not products of the citric acid cycle?
- acetyl-CoA -FAD
select the outcomes of the inhibition of the first step of the citric acid cycle
- acetyl-CoA is channeled into fat synthesis - the citric cycle shuts down
Select the names of the membrane protein complexes that are part of the electron transport chain
- bc1 complex - cytochrome oxidase complex -NADH dehydrogenase
Yeast cells can metabolize sugar under anaerobic conditions by breaking down pyruvate. Which of these are the end products of fermentation in yeast
- ethanol -NAD+ -CO2
which of the following molecules can be used as energy sources by living organisms?
- fats -carbohydrates - proteins
Select the two key points where glucose catabolism is regulated by feedback inhibition
- glycolysis - the krebs cycle
select all of the following that are true statements describing one round of the krebs cycle
- one molecule of ATP is produced - a 2 carbon group from acetyl-CoA enters the cycle - four electrons are produced
Select the possible fates of the pyruvate that is produced by glycolysis
- pyruvate is oxidized into acetyl Co-A and fed into the krebs cycle - the reduction of pyruvate can be used to oxidize NADH back to NAD+
select the processes that release carbon dioxide from glucose
- the citric acid cycle - the conversion of pyruvate to acetyl-CoA
Select the processes that release carbon dioxide from glucose.
- the conversion of pyruvate to acetyl-CoA - the citric acid cycle
Reaction 6 of the Krebs cycle involves the breakdown of succinyl CoA to succinate and CoA and what other processes?
- the phosphorylation of GDP - substrate - level phosphorylation to form ATP
Select the structural components of the electron transport chain
- ubiquinone - cytochrome c - protein complexes
the key product of aerobic respiration, ____ shuts down the biochemical pathways of aerobic respiration when its levels are high, an example of inhibition
1. ATP 2. feedback
citrate NADH ATP
1. inhibits phosphofructokinase 2. inhibits pyruvate dehydrogenase 3. inhibits phosphofructokinase, citrate synthetase, and pyruvate dehydrogenase
Which is the second complex to receive electrons in the transport chain? Which is the first complex to receive electrons in the transport chain?
1.bc1 complex 2. NADH dehydrogenase
glycolysis results in a net gain of _____ molecules of ATP per glucose molecule
2
Select all of the following that are produced by one round of the Krebs cycle
3 molecules of NADH 2 molecules of CO2
in eukaryotes, the predicted yield is ____ ATP molecules per glucose molecule during cellular respiration, while for prokaryotes the predicted yield is ___
30 32
In cellular respiration, electrons are harvested from the bonds of organic molecules containing chemical potential energy and ultimately used to drive the production of the end product ______, which the cell can use to power its activities.
ATP
The first reaction of the citric acid cycle is inhibited when the cell's concentration of ______ is high
ATP
the ultimate goal of cellular respiration is the production of _____, a molecule that powers the work of cells
ATP
using the redox reactions of their energy metabolism, cells extract energy contained in the bonds of organic molecules and convert it to
ATP
low levels of ___ and high levels of ___ activate enzymes in the pathways of aerobic respiration
ATP ADP
carbohydrates and fats contain many energy- rich
C-H bonds
The first five reactions of glycolysis convert glucose into two molecules of _____Those molecules are processed by the second five reactions of glycolysis to yield two molecules of _____ as ATPs is generated.
G3P pyruvate
What reactant of glycolysis is not present in large amounts in the cell and thus must be regenerated for glycolysis to continue?
NAD+
the cofactor _____ plays a role in the catalysis of many redox reactions of energy metabolism enzymes often use a cofactor called ____ to catalyze redox reactions that extract energy from organic molecules
NAD+
The electron transport chain uses electrons carried by ______ to generate a proton gradient that can be used to drive ATP synthesis
NADH and FADH2
Some organisms live in anaerobic environments, meaning that the environments do not have
Oxygen
The first step of fermentation in yeasts is the removal of CO2 from pyruvate to produce which compound?
acetaldahyde
when a carbon dioxide is removed from pyruvate, the product is a _____ group, which then attaches to coenzyme A
acetyl
What molecule enters the Krebs cycle and combines with oxaloacetate to form citric acid?
acetyl-CoA
what molecule enters the krebs cycle and combines with oxaloacetate to form citric acid
acetyl-CoA
Some organisms can use inorganic alternatives to oxygen as the final electron acceptor, such as sulfur or CO2. This process is referred to as what?
anaerobic respiration
In ______ conditions, cells that cannot use a molecule other than oxygen as an electron acceptor for the electron transport chain rely on glycolysis to produce ______
anaerobic; ATP
in terms of the source of their carbon, plants are ____ and animals are _______
autotrophs, heterotrophs
In the electron transport chain, the carrier ubiquinone passes electrons to which of the following?
bc1 complex
Prior to oxidative phosphorylation, the net yield from one glucose molecule going through glycolysis and the Krebs cycle is
c: 6CO2 and 4ATP
During the process of ______, a force similar to osmosis (diffusion of the protons from the high concentration in the intermembrane space to an area of lower concentration within the matrix of the mitochondria) powers the production of ATP from ADP and Pi
chemiosmosis
The use of energy stored in a proton gradient to drive the synthesis of ATP is called:
chemiosmosis
during the first reaction of the citric acid cycle, the 6- carbon molecule ______ is formed when acetyl_CoA joins with oxaloacetate
citrate
the first half of glycolysis does which of the following
converts a glucose molecule to 2 G3P molecules and requires ATP
energy contained in the bonds of food molecules is harvested by enzymes that _____ a little bit at a time
dismantle organic molecules
During each step of the electron transport system, electrons move to a more electronegative carrier, and thus move
down and energy gradient
oxidation is defined as the loss of one or more
electron
What product of yeast fermentation is used in the production of wine and beer and is toxic to the yeast at a concentration of 12%?
ethanol
during fermentation in yeast cells, pyruvate decarboxylated to acetaldehyde, which accepts a pair of electrons from NADH to produce NAD+ and ____
ethanol
True or false: The net gain of ATP from glycolysis is 4.
f
The end product of glycolysis, pyruvate, may be oxidized to acetyl-CoA or reduced during
fermentation
select the ways that NADH can be recycled to NAD+ so that glycolysis can continue
fermentation aerobic respiration
the second half of glycolysis
generates ATP
during glycolysis, one molecule of _____ is broken down into two molecules of pyruvate, driving the synthesis of ATP
glucose
the first 5 steps of the glycolytic pathway convert one molecule of _____ into 2 molecules of _____
glucose G3P
in aerobic respiration, ____is oxidized to CO2, not by direct transfer of electrons to Oz as in combustion, but my transferring electrons to intermediate electron ____ and then eventually to O2
glucose, carriers
In the absence of oxygen, what pathway do cells that are unable to conduct anaerobic respiration rely on to produce ATP
glycolysis
The metabolic pathway in which glucose is converted into 2 pyruvate molecules to yield two ATP molecules is called ----
glycolysis
in several stages, cells extract energy from complex molecules mainly by
harvesting energy from C-H bonds
Some organisms conduct anaerobic respiration to make ATP, using a(n) ______ molecule as a final electron acceptor for an electron transport chain.
inorganic
In eukaryotes, the electron transport chain occurs in the inner ______ membrane
mitochondrial
where does the citric acid occur in eukaryotic cells
mitochondrial matrix
to generate ATP in the absence of oxygen, many cells conduct fermentation, in which electrons are donated to ___ and ___ is regenerated to allow glycolysis to continue
organic molecules NAD+
over several steps, citrate is decarboxylated and oxidized, ultimately regenerating ______ for the next round of the krebs cycle
oxaloacetate
the reactions of energy metabolism in which energy is harvested from organic molecules are ______ reactions
oxidation
the two reactions involved in a redox reaction are _____- and _____
oxidation, reduction
during the krebs cycle, citrate proceeds through several ________ reactions, yielding electrons to be donated to electron carriers, two molecules of ______ and _____ to begin the cycle again
oxidation; CO2; oxaloacetate
in the process of aerobic respiration, glucose is _____ to CO2, but unlike combustion, electrons are first transferred to electron carriers before they are donated to the final electron acceptor oxygen.
oxidized
The electron transport chain is composed of a series of membrane-associated
proteins
Each membrane protein complex in the electron transport chain functions as which of the following?
proton pump
dehydrogenations are reactions in which electrons lost by a molecule are accompanied by
protons
the protein complexes of the electron transport chain drive ________ into the inter-membrane space of the mitochondria
protons
select molecules that are produced during the second half of glycolysis
pyruvate ATP
energy is extracted from food molecules using enzyme-catalyzed ______ reactions that convert the energy to ATP
redox
in energy metabolism, cells couple oxidation reactions with reduction reactions. Collectively these reactions are called _____ reactions.
redox
when an atom accepts an electron it is said to be
reduced
during the oxidation of pyruvate, acetly-CoA is formed during a reaction that also does which of the following
removes a CO2 from pyruvate
During the sixth reaction of the citric acid cycle, the high-energy bond between the 4-carbon succinyl group and CoA is cleaved to drive the formation of what products?
succinate, GTP, then ATP
Energy captured by NADH during the passage of glucose through glycolysis and the citric acid cycle is carried to
the electron transport chain
What uses the energy contained in NADH and FADH2 to create a proton gradient for ATP synthesis?
the electron transport chain
During aerobic respiration, NADH delivers electrons to ______, and then ______ captures electrons at the end and joins with hydrogen to form water.
the electron transport chain; oxygen
which is the first reaction of the citric acid cycle
the joining of acetyl-CoA to oxaloacetate
What protein complex in the electron transport chain donates electrons to oxygen to form water?
the last one
In the cleavage reaction of glycolysis, a 6-carbon diphosphate sugar is split into which of the following?
two 3- carbon monophosphate sugars
in the electron transport chain, an electron carrier called _______ passes electrons from NADH dehydrogenase to the bc1 complex
ubiquinone
The key to calculating the P/O ratio is
understanding that a proton gradient drives the synthesis of ATP by the enzyme ATP synthase
earths first organisms
were anaerobic