Cellular Respiration in Detail

Cellular Respiration

The process where stored energy is converted to a usable form.

Oxygen and glucose are converted to carbon dioxide, water, and ATP.

A. plants onlyB. animals onlyC. eukaryotes onlyD. all organisms

Question 1: Who performs cellular respiration?

D. All organisms

Cellular Respiration Equation

(Opposite of photosynthesis)

C6H12O6 + 6O2 6CO2 + 6H2O + up to 38ATP(glucose) + (oxygen) (carbon dioxide) + (water) + (energy)

Question 2: What is the chemical formula for glucose?

A. C4H8O4

B. C5H10O5

C. C6H12O6

D. C7H14O7

C. C6H12O6

The Importance of Cellular Respiration

Cellular respiration is the process organisms use to extract the chemical energy from their food.

Cells use the energy (ATP) from cellular respiration for chemical, mechanical, and transport work.

Question 3: Which of the three types of cellular work involves physically moving cell structures?A. Transport workB. Chemical workC. Mechanical workD. All of the above

C. Mechanical work

Stage 1: Glycolysis (“Glucose-Breaking”)

Takes place in the cytoplasmTwo ATP molecules are required to

initiate the reaction.The reaction eventually yields 2

pyruvic acid molecules and 4 ATP molecules.

There is a net gain of 2 ATP molecules.

Glycolysis Yields a Net Gain of 2 ATP

What You Need to Know About Glycolysis

Question 4: Which of the following statements about glycolysis is FALSE?A. Two ATP molecules are used.B. Four ATP molecules are produced. C. Two molecules of pyruvic acid are

produced.D. The two pyruvic acid molecules hold

more energy than the original glucose molecule.

D. The 2 pyruvic acids actually have LESS energy than the original glucose (fewer bonds).

(24 bonds) (22 bonds)

Stage 2: The Krebs Cycle In 1937, Hans A. Krebs

proposed a specific metabolic pathway that provided the energy used by cells.

The cycle he described is now called the “Krebs Cycle” in his honor.

The Krebs cycle produces 2 more ATP.

Stage 2: The Krebs Cycle

What You Need to Know About the Krebs Cycle

Question 5: How many times does the Krebs cycle “turn” for each glucose molecule?

A. 1 timeB. 2 timesC. 3 timesD. 4 times

B. 2 times (each glucose is broken in half before entering the Krebs cycle)

MitochondrionThe “Powerhouse of the Cell”

Question 6: Where does the Krebs cycle take place? A. In the chloroplast.B. In the cytoplasm of the cell.C. Inside the inner membrane of the

mitochondrion.D. Between the inner and outer membranes of

the mitochondrion.

C. The Krebs cycle take place in the matrix of the mitochondrion.

Stage 3: Electron Transport Chain and ATP Synthase Action Uses the flow of electrons from NADH

and FADH2 to pump H+ out of the mitochondrial matrix to the intermembrane space.

The flow of the H+ back into the matrix provides the energy that is used to combine ADP and P to produce ATP.

Water is produced as the hydrogen ions and electrons combine with oxygen.

What You Need to Know

Question 7: Without oxygen, most of your cells would be unable to produce much ATP. A. TrueB. False

True: Oxygen is required as the final electron acceptor in the electron transport chain.