Chapter 9 Part 1: Cellular Respiration

What can all the energy in food be traced back to?

All the energy in food can be traced back to sunlight.

Without oxygen, what would happen to our muscles?

Without oxygen, our muscles would shut down.

What is cellular respiration?

Cellular respiration is the process of cells releasing the chemical energy stored in foods in the presence of O2.

What is the overall equation for cellular respiration?

C6H12O6 + 6O2 becomes 6CO2 + 6H2O + ATP

What are the reactants of cellular respiration?

C6H12O6 (glucose), 6O2 (oxygen)

What are the products of cellular respiration?

6CO2 (carbon dioxide), 6H2O (water), ATP (energy)

Besides glucose, what other kinds of molecules can be used in cellular respiraton?

Besides glucose, cellular respiration can burn carbohydrates, fats, and proteins.

What is the relationship between cellular respiration and breathing?

Cellular respiration requires a cell to exchange gases with its surroundings. Breathing exchanges these gases between the blood and outside air.

What are the 3 main stages of cellular respiration?

The 3 main stages are glycolysis, the Krebs cycle (Citric Acid Cycle), and the electron transport chain (ETC).

Where does cellular respiration occur?

Cellular respiration occurs in the mitochondria.

Where does glycolysis occur?

Glycolysis occurs in the cytoplasm outside of the mitochondria (its products enter the mitochondria, however, when cellular respiration takes place).

Where does the Krebs cycle occur?

The Krebs cycle occurs in the matrix of the mitochondria.

Where does the ETC occur?

The ETC occurs in the cristae (folds in the inner membrane of the mitochondria).

Is glycolysis aerobic or anaerobic?

Anaerobic (doesn't require oxygen).

What are the reactants of glycolysis?

C6H12O6 (glucose), 2 ATP, 2 NAD+

What are the products of glycolysis?

2 pyruvic acid, 2 ATP, 2 NADH

How many ATP molecules are needed to start glycolysis?

2

How many ATP molecules are produced in glycolysis?

2

What is the overall net gain of ATP for every molecule of glucose that goes through glycolysis?

2

Are the Krebs cycle and the ETC aerobic or anaerobic?

Aerobic (require oxygen).

What are the reactants of the Krebs cycle?

2 pyruvic acids, ADP, NAD+, FAD+

What are the products of the Krebs cycle?

6CO2 (byproduct), 2 ATP, NADH, FADH

What reactants of the Krebs cycle are products of glycolysis?

Pyruvic acid and NAD+

What reactants of the Krebs cycle are products of the ETC?

FAD+

Where does the 6CO2 produced by the Krebs cycle go?

Leaves as a byproduct.

Where does the 2 ATP produced by the Krebs cycle go?

Throughout the cell to fuel various cellular functions.

Where does the NADH and FADH produced by the Krebs cycle go?

They go to the ETC.

What are the reactants of the ETC?

6O2, NADH, FADH2

Where does the 6O2 that goes into the ETC come from?

It is inhaled and enters from outside.

Where does the NADH and FADH that go into the ETC come from?

They come from the Krebs cycle.

What are the products of the ETC?

6H2O (byproduct), 32 ATP, NAD+, FAD+

Where does the 6H2O produced by the ETC go?

Leaves as a byproduct.

Where does the NAD+ and the FAD+ produced by the ETC go?

They go to glycolysis and the Krebs cycle.

How does 6H2O form during the ETC?

6H2O forms during the ETC when O2 (from outside) and H+ ions (carried by NADH and FADH), combine.

What is the total energy yield of cellular respiration?

36 ATP

What percentage of the total energy of glucose does cellular respiration represent?

The percentage of the total energy of glucose that cellular respiration represents is 36%.

What happens to the remaining 64% of energy from glucose that is not used in cellular respiration?

The remaining 64% of energy from glucose that is not used in cellular respiration is released as heat.

Describe the connection between photosynthesis and cellular respiration.

Photosynthesis removes CO2 from the atmosphere and turns it into glucose and O2. Cellular respiration uses that O2 to release energy from food and CO2, which plants then use in order for photosynthesis to take place.