Biology: 9.2 The Process of Cellular Respiration

Glycolysis: per one molecule of glucose is how much pyruvic acid converted?

2 molecules of pyruvic acid

What are the products of glycolysis?

2 molecules of pyruvic acid

How many molecules of ATP are produced in the entire breakdown of glucose?

36 molecules of ATP per molecule of glucose.

Glycolysis: first stage of cellular respiration

ATP and NADH are produced during glycolysis

The Krebs cycle: Citric Acid Production: Acetyl-CoA combines with a 4-carbon compound in the Krebs cycle to produce citric acid.

Acetyl-CoA Adds the 2-carbon acetyl group to a 4-carbon molecule already resent, producing a 6-carbon molecule called citric acid.

How does the cell use the charge differences that build up across the inner mitochondrial membrane during cellular respiration?

As in photosynthesis, the cell uses a process known as Chem i osmosis to produce ATP.

The Krebs cycle: Energy extraction

At five places in the cycle, electron carriers accept a pair of high-energy electrons, and NAD+ and FAD are converted to NADH and FADH2.

Look at figure 9-5 and list the products of the Krebs cycle. What happens to each of these products?

Carbon dioxide as a by-product, ATP, NADH, FADH2: -Carbon dioxide is not useful in the cell and is expelled every time you exhale. -The ATP molecules are very useful and become immediately available to power cellular activities. -Carrier molecules like NADH, FADH2, int he presence of oxygen, the electrons they hold are used to generate huge amounts of ATP in the electron transport chain.

The Krebs cycle: Energy extraction

Citric acid is broken down into a 4-carbon molecule, more carbon dioxide is released, and electrons are transferred to energy carriers.

What happens during the process of glycolysis?

During glycolysis, 1 molecule of glucose, a 6-carbon compound, is transformed into 2 molecules of pyruvic acid, a 3-carbon compound.

What happens during th Krebs cycle?

During the Krebs cycle, pyruvic acid is broken down into carbon dioxide in a series of energy-extracting reactions.

Electron transport: notice the electron carriers shown in the image as purple spheres

Electron transport chain is composed of a series of electron carriers located in the inner membrane of the mitochondrion.

Electron transport: NADH and FADH2 are by-products of glycolysis and the Krebs cycle

Electron transport uses the high-energy electrons from glycolysis and the Krebs cycle to synthesize ATP from ADP.

The Krebs cycle: Energy extraction

For each turn of the cycle, a molecule of ADP is converted to a molecule of ATP.

Total ATP from Cellular Respiration:

Glycolysis, the Krebs cycle, and the electron transport chain release about 36 molecules of ATP per molecule of glucose.

How is the function of NAD+ similar to that of NADP+?

In photosynthesis, each NAD+ molecule accepts a pair of high-energy electrons and they are both electron carriers.

How is the cell like a furnace?

Like a furnace that can burn oil, gas, or wood, the cell can generate chemical energy in the form of ATP from just about any source.

Electron transport: the third stage of cellular respiration

Products from the Krebs cycle and glycolysis feed into the last step of cellular respiration.

The Krebs Cycle

Pyruvic acid from glycolysis is used to make NADH, ATP, FADH2, with carbon dioxide as a by-product.

The Krebs cycle: the second stage of cellular respiration

Pyruvic acid is broken down into carbon dioxide in a series of energy-extracting reactions.

What happens to pyruvic acid in the Krebs cycle?

Pyruvic acid is broken down into carbon dioxide in a series of energy-extracting reactions.

How does the electron transport chain use the high-energy electrons from glycolysis and the Krebs cycle?

The electron transport chain uses the high-energy electrons from glycolysis and the Krebs cycle to convert ADP to ATP.

Electron Transport: ATP Production

The inner mitochondrial membrane contains enzymes known as ATP synthase. The cell uses a process known as Chemiosmosis to produce ATP.

How much ATP does cellular expiration generate?

Together, glycolysis, the Krebs cycle, and the electron transport chain release about 36 molecules of ATP per molecule of glucose.

The Krebs cycle: through the beginning of the Krebs cycle

pyruvic acid from glycolysis passes through the two membranes of the mitochondrion and into the matrix.