Cellular Respiration

Question 1

What is anaerobic respiration?

Answer 1

Respiration that occurs in the absence of oxygen
(glucose —> lactic acid + energy released)

Question 2

What is aerobic respiration?

Answer 2

Respiration that occurs in the presence of oxygen
(glucose + oxygen —> CO2 + energy released)

Question 3

Where does anaerobic respiration occur?

Answer 3

The cytoplasm

Question 4

Where does aerobic respiration occur?

Answer 4

The cytoplasm and the mitochondria

Question 5

What are the stages of anaerobic respiration?

Answer 5

• Glycolysis
• 2 molecules of pyruvate are produced from 1 glucose molecule, in addition to the formation of 2 ATP molecules, and 2 NADH molecules.
• If no O2 is present/limited, this finishes as lactic acid.

Question 6

What are the 3 stages of aerobic respiration?

Answer 6

• Glycolysis
• Citric Acid Cycle (Krebs Cycle)
• Electron Transport Chain (E.T.C)

Question 7

Aerobic glycolysis?

Answer 7

• 2 molecules of pyruvate are produced from 1 glucose molecule, in addition to the formation of 2 ATP molecules, and 2 NADH molecules.
• If no O2 is present/limited, this finishes as lactic acid, but if oxygen is present, the pyruvate molecules produced go on to initiate the Krebs Cycle.

Question 8

Krebs Cycle?

Answer 8

• Pyruvate enters mitochondria, and CO2 is removed.
• Removal of CO2 forms Acetylcoenzyme A, and when this combines with oxaloacetate, citrate is formed.
• CO2 is released as a by-product.
• Dehyrdogenase enzymes remove H ions and electrons from the intermediate molecules, which then form NADH.
• The high-energy electrons are then passed to the E.T.C.

Question 9

Electron Transport Chain?

Answer 9

• The last stage of aerobic respiration.
• The E.T.C is a collection of proteins found on the inner membrane of the mitochondria.
• The electrons pump their energy into the proteins, releasing H ions and electrons.
• The energy provided enables the H ions to be pumped across the membrane.
• ATP synthase enables the ions to be pumped back across the membrane.
• Oxygen is the final electron acceptor, combining with the electrons and H ions to form water.
• 38 ATP molecules are formed in total, from the 1 glucose molecule in glycolysis.