Cell Respiration

Organic compounds such as glucose store energy in their _________. These molecules are broken down and their energy extracted in _____.

The most prevalent and efficient catabolic pathway for the production of ATP, in which oxygen is consumed as a reactant along with the organic fuel.

An organelle in eukaryotic cells that serves as the site of cellular respiration.

An organic molecule serving as a cofactor. Most vitamins function as coenzymes in important metabolic reactions.

The first stage of cellular respiration occurs in the ____, while the second and third stages occur in _____.

In cellular respiration, electrons are transferred from glucose to ____ such as ____ and finally to ____; the energy released by this relocation of electrons is used to make ____. ____and ____ are given off as byproducts.

The splitting of glucose into pyruvate; one metabolic pathway that occurs in all living cells, serving as the starting point for fermentation or aerobic respiration.

Glycolysis is a series of steps in which a glucose molecule is broken down into two molecules of ___.

As the chemical bonds in glucose are broken, electrons (and hydrogen ions) are picked up by ___ forming ___. Glucose is oxidized and ___ is reduced.

A net output of __ ATP molecules are also produced in glycolysis for every glucose molecule processed. But most of the energy released by the breakdown of glucose is carried by the electrons attached to __.

A chemical cycle involving eight steps that completes the metabolic breakdown of glucose molecules to carbon dioxide; occurs within the mitochondrion; the second major stage in cellular respiration.

The pyruvate molecules are modified as they enter the mitochondrion, releasing ____. The altered molecules enter a series of reactions called the _____.

More carbon dioxide is released as the ___ completes the oxidation of glucose. __ ATPs are formed per glucose, but most of the energy released by the oxidation of glucose is carried by ___ and ___.

The loss of electrons from a substance involved in a redox reaction.

Almost all of the ATP produced by cellular respiration is banked in the final phase— ______. The NADH and FADH2 molecules produced in glycolysis and the citric acid cycle donate their electrons to the _____.

At the end of the chain, ____ exerts a strong pull on the electrons, and combines with them and hydrogen ions (protons) to form ___.

The _____converts chemical energy of moving electrons to a form that can be used to drive _____, which produces about ___ ATP molecules for each glucose molecule consumed.

___, which begins the breakdown of glucose, is a series of _______ that can be divided into _____.

In the ______, some ATP energy is used to start the process of _____. By the end of this phase, a __-carbon molecule (glucose) has been split into two __-carbon molecules of _______

The formation of ATP by directly transferring a phosphate group to ADP from an intermediate substrate in catabolism.

The 3-carbon glyceraldehyde-3-phosphate molecules now enter the ____.

In the _____, chemical bonds are broken, and NAD+ picks up electrons and hydrogen ions, forming NADH. The energy released is used to attach ____ groups. The phosphates are transferred to ADP, finally making some ATP. This way of making ATP is called _____.

In the energy-payoff phase, a couple more reactions rearrange the atoms in the __-carbon molecules. More ATP is generated in the final reaction that yields ____. For each glucose molecule broken down during glycolysis, a net of ___ ATPs are formed, along with two ___ molecules.

the entry compound for the citric acid cycle in cellular respiration, formed from a fragment of pyruvate attached to a coenzyme.

The oxidation of glucose continues in the ___.

____ molecules formed during glycolysis diffuse from the cytosol into the mitochondrion, but ____ itself does not enter the citric acid cycle.

A reaction occurs that removes a carbon atom, releasing it in ____. Electrons are transferred to an ___ molecule, storing energy. ___ joins with the ____, forming ____.

One molecule of ___enters the citric acid cycle.

The 2-carbon fragment of ____ attaches to the 4-carbon molecule ____ in the first reaction of the cycle. This forms ____.

In a series of steps, bonds ___ and ___. ___ carbon atoms are released, one at a time, in molecules of ____. Electrons are carried off by molecules of ___ and ____. One step produces an ATP molecule by ___. A 4-carbon ___ molecule is regenerated.

Since two ____ molecules are produced for each glucose molecule broken down, a second ____enters the citric acid cycle. The same series of reactions occurs.

The cell has gained ___ ATPs that can be used directly. However, most of the energy originally contained in the bonds of glucose is now carried by the ___ and ___ molecules.

Most of the energy harvested from organic molecules during ___ and the ___is stored in NADH and FADH2.

NADH and FADH₂ give up their high-energy electrons in the third phase of cellular respiration—____ —where most of the cell's ATP fuel is produced.

A sequence of electron carrier molecules (membrane proteins) that shuttle electrons during the redox reactions that release energy used to make ATP; an array of molecules- mostly proteins- built into the inner membrane of the mitochondria

NADH gives up its high-energy electrons to the first complex in the ____. The electrons move from one member of the chain to the next, giving up their energy as they are pulled from NADH toward highly _____. The energy given up by the flow of electrons is used to pump ___ from the mitochondrial matrix into the intermembrane space.

___ captures the electrons in the very last step in electron transport. The last complex adds a pair of electrons to an oxygen atom and two hydrogen ions, forming ___.

The compartment of the mitochondrion enclosed by the inner membrane and containing enzymes and substrates for the Krebs cycle.

The backed-up hydrogen ions, which have alot of ___, give up their energy when they diffuse through a special protein in the membrane called ___.

As hydrogen ions flow down their concentration gradient, ____ captures their energy to make ATP. This mode of ATP production is called _____ because it is powered by the transfer of electrons to oxygen.

Under normal conditions, almost all the ATP produced in the process of cellular respiration is manufactured by ____ and ____— about ___ ATPs for every glucose consumed.

__ and ___ produce a small amount of ATP via ___, but most of the cell's ATP is made via ____, when NADH and FADH₂ produced in ___ and ___ give up to oxygen the electrons obtained from organic molecules.

All cells are able to synthesize ATP via the process of ____.

In many cells, if oxygen is not present, pyruvate (pyruvic acid) is metabolized in a process called _____.

By oxidizing the NADH produced in glycolysis, ____ regenerates NAD+, which can take part in glycolysis once again to produce more ATP.

The net energy gain in fermentation is __ ATP molecules per molecule of glucose.

____ complements ____ and makes it possible for ATP to be continually produced in the absence of oxygen.

A catabolic process that makes a limited amount of ATP from glucose without an electron transport chain and that produces a characteristic end product, such as ethyl alcohol or lactic acid.

There are two types of fermentation: _____ and _____

____, which occurs in yeast, results in the production of ethanol and carbon dioxide from the conversion of pyruvate.

_____, which occurs in muscle, results in the production of lactate (lactic acid) from the conversion of pyruvate.

The reduced form of nicotinamide that is one of the products of glycolysis.

Glycolysis produces ___, ___, and ___ .

If oxygen is not present, NADH cannot be oxidized in the ______.

Without ____, the cell would run out of NAD+, bringing glycolysis to a halt.

In ____, the pyruvate (pyruvic acid) from glycolysis loses one carbon in the form of ____and the product is then reduced to ___by NADH. With the formation of ___, NADH is oxidized and becomes ____.

With a continuous supply of NAD+, ____ can continue, producing more ATP.

During _____, the NADH produced by glycolysis is oxidized, ensuring a continuous supply of NAD+ for glycolysis.

_____ occurs in yeast cells.

In _____, the pyruvate (pyruvic acid) from glycolysis is reduced to ____ by NADH. With the formation of ____, NADH is oxidized and becomes ____.

_____ occurs in muscle cells.