chapter 6

Question 1

what is cellular respiration?

Answer 1

cells use glucose & oxygen to make energy, producing carbon dioxide & water

Question 2

what is the balanced equation for cellular respiration?

Answer 2

C6H12O6 + 6O2—-> 6CO2 + 6H20 + ATP

Question 3

what are the 4 stages of cellular respiration

Answer 3

glycolysis, pyruvate oxidation, krebs cycle, and oxidative phosphorylation

Question 4

what generally occurs during glycolysis

Answer 4

glucose is broken down into two pyruvate molecules, producing a net gain of 2 ATP and 2 NADH.

Question 5

what are the energy investment phases

Answer 5

the cell uses 2 ATP to prepare glucose for breakdown by adding phosphates

Question 6

What is the name of the three-carbon molecule produced during glycolysis, and how many are formed for each molecule of glucose?

Answer 6

pyruvate, and two pyruvate molecules are formed for each molecule of glucose.

Question 7

What is substrate level phosphorylation?

Answer 7

a process where an enzyme transfers a phosphate from a substrate to ADP, to make ATP without needing an electron transport chain or oxygen.

Question 8

How many molecules of ATP are used and produced during glycolysis from each molecule of glucose?

Answer 8

2 molecules of ATP are used in the energy investment phase, and 4 molecules of ATP are produced in the energy harvest phase, resulting in a net gain of 2 ATP molecules per molecule of glucose.

Question 9

How many molecules of NADH are produced during glycolysis for each molecule of glucose?

Answer 9

During glycolysis, 2 molecules of NADH are produced for each molecule of glucose.

Question 10

What generally occurs during pyruvate oxidation?

Answer 10

During pyruvate oxidation, each pyruvate is converted into acetyl CoA, releasing one CO₂ and producing one NADH per pyruvate molecule.

Question 11

How many molecules of ATP, NADH, and CO2 are produced during pyruvate oxidation?

Answer 11

During pyruvate oxidation, no ATP is produced, but 1 NADH and 1 CO₂ are produced per pyruvate molecule, resulting in a total of 2 NADH and 2 CO₂ per glucose molecule.

Question 12

What generally occurs during the Krebs cycle?

Answer 12

In the Krebs cycle, acetyl CoA is broken down to produce ATP, NADH, FADH₂, and CO₂ as a byproduct, generating energy carriers for the electron transport chain.

Question 13

How many molecules of ATP, NADH, FADH2, and CO2 are produced during the Krebs cycle?

Answer 13

The Krebs cycle produces 1 ATP, 3 NADH, 1 FADH₂, and 2 CO₂ per acetyl CoA, resulting in a total of 2 ATP, 6 NADH, 2 FADH₂, and 4 CO₂ per glucose molecule.

Question 14

What combines with acetyl CoA to form citrate? How many rotations of the Krebs cycle are completed for each molecule of glucose?

Answer 14

Oxaloacetate combines with acetyl CoA to form citrate, and the Krebs cycle completes two rotations per glucose molecule.

Question 15

What generally occurs during oxidative phosphorylation

Answer 15

In oxidative phosphorylation, electrons from NADH and FADH₂ travel through the electron transport chain, creating a proton gradient that drives ATP synthesis, with oxygen as the final electron acceptor, forming water.

Question 16

How many molecules of ATP, NADH, FADH2, and CO2 are produced during oxidative phosphorylation?

Answer 16

During oxidative phosphorylation, approximately 28-34 ATP molecules are produced per glucose molecule, with NADH and FADH₂ supplying electrons, but no additional NADH, FADH₂, or CO₂ is generated.

Question 17

Why is oxygen required during the oxidative phosphorylation stage and what is it’s fate

Answer 17

it’s the final electron acceptor and it combines with electrons and protons to form water.

Question 18

How are hydrogen ions moved into the intermembrane space, and what is the result of the accumulation of hydrogen ions?

Answer 18

Hydrogen ions are pumped into the intermembrane space by the electron transport chain, creating a proton gradient that drives ATP synthesis as the ions flow back through ATP synthase.

Question 19

What is the path that most electrons follow

Answer 19

electrons move from glucose to NADH to electron transport chain to oxygen

Question 20

What is ATP synthase

Answer 20

an enzyme that uses the flow of hydrogen ions back into the mitochondrial matrix to produce ATP from ADP and inorganic phosphate.

Question 21

What is one advantage and one disadvantage to anaerobic pathways?

Answer 21

advantage: they can produce ATP quickly without requiring oxygen
disadvantage: they produce far less ATP per glucose molecule than aerobic pathways and can lead to the buildup of lactic acid.

Question 22

What are the balanced equations
for alcoholic fermentation and lactic acid fermentation?

Answer 22

alcoholic fermentation: C6H12O6 —> 2 CO2 + 2 C2H5OH + 2 ATP
lactic acid fermentation: C6H12O6 —-> 2 C3H6O3 + 2 ATP