When pyruvic acid is converted to acetyl CoA, the former is:

1.	Oxidized	2.	Reduced
3.	Isomerized	4.	Caboxylated

A five carbon amino acid can be formed by which of the following intermediates of Krebs cycle?

The number of molecules of carbon dioxide produced by three turns of the Krebs cycle would be:

What is the total number of NADH and ${\mathrm{FADH}}_2$ molecules produced for each molecule of glucose metabolized by glycolysis and the citric acid cycle?

The correct sequence of electron flow during aerobic respiration would be:
1. food → Krebs cycle → ATP → NAD⁺
2. food → NADH → electron transport chain → oxygen
3. glucose → pyruvate → ATP → oxygen
4. glucose → ATP → electron transport chain → NADH

The components of the mitochondrial electron transport chain are located:
1. in mitochondrial matrix
2. in outer mitochondrial membrane
3. in inner mitochondrial membrane
4. in intermembrane space

The correct sequence of flow of electrons downhill in the mitochondrial electron transport chain would be:
1. ubiquinone, cytochromes, FMN, Fe-S
2. cytochromes, FMN, ubiquinone, Fe-S
3. Fe-S, FMN, cytochromes, ubiquinone
4. FMN, Fe-S, ubiquinone, cytochromes

Electron is donated to the mitochondrial ETC at the lowest energy level by:

The source of oxygen for the synthesis of water in oxidative phosphorylation is:
1. carbon dioxide
2. glucose
3. molecular oxygen
4. pyruvate

When electron pass downhill in the ETC, the energy released is used to pump protons into:
1. matrix of mitochondria
2. cytosol
3. mitochondrial inner membrane
4. mitochondrial intermembrane space