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 ___

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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