1. The complete breakdown of glucose in the presence of oxygen occurs in two stages: glycolysis and (). The first of these stages occurs in the () of the cell, and the second stage occurs in organelles called (). Which stage generates the most ATP

The complete breakdown of glucose in the presence of oxygen occurs in two stages: glycolysis and citric acid cycle. The first of these stages occur in the cytoplasm of the cell, and the second stage occurs in organelles called Mitochondria.

Explanation:

The breakdown of glucose occurs in two stages. The first stage occurs inside the cytoplasm, it is called glycolysis. when a molecule of glucose undergoes glycolysis, the following are produced:

2 ATP (Adenosine triphosphate) molecules;

2 water molecules;

2 pyruvate molecules and;

2 NADH (Nicotinamide Adenine dinucleotide) molecules

The second stage occurs in an organelle called Mitochondria, it is called citric acid cycle or tricarboxylic acid or Kreb's cycle. In this stage, the two pyruvate molecules from the glycolytic cycle are reduced to carbon (iv) oxide. The following are produced:

2 ATP molecules;

6 NADH molecules;

2 FADH2 (flavine adenine dinucleotide) and;

4 molecules of carbon (iv) oxide.

The NADH and FADH2 molecules are used in the electron transport chain generates as much as 28 ATP molecules.