Cellular Energy - Stages of Cellular Respiration

Question 1

Glycolysis​

Answer 1

• 1 molecule of glucose is broken in half, producing 2 molecules of pyruvic acid​
• This occurs in the ​cytoplasm of the cell.
• C6H12O6 (glucose) broken into 2 molecules of C3H6O3 (pyruvic acid)
• Also we get 2 net ATP and NADH from Glycolysis.
• Glycolysis does not require oxygen so it is an anaerobic process.

Question 2

Kreb’s Cycle (Citric Acid Cycle)

Answer 2

• ​​The 2 molecules of pyruvic acid are broken down into carbon dioxide and during that process NADH and FADH2 molecules are made.​
• NADH and FADH2 are electron carriers.
• This occurs in the matrix of the mitochondria.
• This process does not use oxygen but it only happens when oxygen is present to go on to the next step.​​

Question 3

​Electron Transport Chain (ETC) ​

Answer 3

• The NADH and FADH2 molecules from Glycolysis and the Kreb’s Cycle are used to make ATP.
• The electrons that these molecules carried from the other steps are high energy electrons and they are used to convert ADP to ATP by adding a phosphate group.
• The ETC requires oxygen so it is an aerobic process.
• This occurs within the inner membrane folds called cristae.
• By the end of this step approximately 36 molecules of - ATP are made by Cellular Respiration.