Chapter 23, Problem 23.58P

Interpretation Introduction

(a)

Interpretation:

The product formed from NADH in the electron transport chain should be determined.

Concept Introduction:

Aerobic respiration occurs in two steps:

• Glycolysis
• Citric acid cycle

Glycolysis is the first step that forms pyruvate as given below;

  ${\text{Glucose + 2ATP + 2NAD}}^{\text{+}}{\text{ + 4ADP + 2P}}_{\text{i}}\stackrel{}{\to }{\text{ 2 Pyruvate + 4ATP + 2NADH + 2H}}^{\text{+}}$

In the presence of oxygen means aerobic respiration, this pyruvate enters in the Krebs cycle and extracts energy in the form of electrons transfer. Electrons are transferred from the pyruvate to the receptors like ${\text{NAD}}^{\text{+}}{\text{, GDP, and FAD and CO}}_{\text{2}}$ gas is formed as the waste product. The products of citric acid cycles act as precursors for electron transport chains.

Answer to Problem 23.58P

NADH produces two ATPs for every NADH₂ molecule.

Explanation of Solution

The citric acid cycle is also known as the tricarboxylic acid cycle or Krebs cycles. In this cycle, all intermediates are carboxylate anions mainly which are formed from di or tricarboxylic acid during the reaction. It initiates with the reaction of acetyl CoA (a 2 C's substance) that reacts with a 4 C's substance to form a product of 6 C's. Later carbon atoms are removed in the form of carbon dioxide gas.

In this process, 2 H's are transferred to FAD and produce FADH₂. This energy carrier remains attached to the enzyme and transfers the electrons to the electron transport chain. The electron transport chain is a series of four enzyme complexes and two coenzymes:

• Complex I to Complex IV
• Coenzymes -ubiquinone and Cytochrome c

NADH is created through reduction-oxidation reactions in the Krebs cycle during respiration. It gives its electrons in the electron transport chain that produces two ATPs for every NADH₂ molecule.

Interpretation Introduction

(b)

Interpretation:

The product formed from ${\text{FADH}}_{\text{2}}$ in the electron transport chain should be determined.

Concept Introduction:

Aerobic respiration occurs in two steps;

• Glycolysis
• Citric acid cycle

Glycolysis is the first step that forms pyruvate as given below;

  ${\text{Glucose + 2ATP + 2NAD}}^{\text{+}}{\text{ + 4ADP + 2P}}_{\text{i}}\stackrel{}{\to }{\text{ 2 Pyruvate + 4ATP + 2NADH + 2H}}^{\text{+}}$

In the presence of oxygen means aerobic respiration, this pyruvate enters the Krebs cycle and extracts energy in the form of electrons transfer. Electrons are transferred from the pyruvate to the receptors like ${\text{NAD}}^{\text{+}}{\text{, GDP, and FAD and CO}}_{\text{2}}$ gas is formed as the waste product. The products of citric acid cycles act as precursors for electron transport chains.

Answer to Problem 23.58P

The ${\text{FADH}}_{\text{2}}$ molecule produces two ATP molecules in the electron transport chain.

Explanation of Solution

The citric acid cycle is also known as the tricarboxylic acid cycle or Krebs cycles. In this cycle, all intermediates are carboxylate anions mainly which are formed from di or tricarboxylic acid during the reaction. It initiates with the reaction of acetyl CoA (a 2 C's substance) that reacts with a 4 C's substance to form a product of 6 C's. Later carbon atoms are removed in the form of carbon dioxide gas.

In this process, 2 H's are transferred to FAD and produce FADH₂. This energy carrier remains attached to the enzyme and transfers the electrons to the electron transport chain. The electron transport chain is a series of four enzyme complexes and two coenzymes:

• Complex I to Complex IV
• Coenzymes -ubiquinone and Cytochrome c

  ${\text{FADH}}_{\text{2}}$ is created from through reduction-oxidation reactions in the Krebs cycle during respiration. It gives its electrons in the electron transport chain that produces two ATPs molecules.

Interpretation Introduction

(c)

Interpretation:

The product formed from ADP in the electron transport chain should be determined.

Concept Introduction:

Aerobic respiration occurs in two steps;

• Glycolysis
• Citric acid cycle

Glycolysis is the first step that forms pyruvate as given below;

  ${\text{Glucose + 2ATP + 2NAD}}^{\text{+}}{\text{ + 4ADP + 2P}}_{\text{i}}\stackrel{}{\to }{\text{ 2 Pyruvate + 4ATP + 2NADH + 2H}}^{\text{+}}$

In the presence of oxygen means aerobic respiration, this pyruvate enters the Krebs cycle and extracts energy in the form of electrons transfer. Electrons are transferred from the pyruvate to the receptors like ${\text{NAD}}^{\text{+}}{\text{, GDP, and FAD and CO}}_{\text{2}}$ gas is formed as the waste product. The products of citric acid cycles act as precursors for electron transport chains.

Answer to Problem 23.58P

In the electron transport chain, ADP involves in the formation of ATP molecules in the mitochondria.

Explanation of Solution

The citric acid cycle is also known as the tricarboxylic acid cycle or Krebs cycles. In this cycle, all intermediates are carboxylate anions mainly which are formed from di or tricarboxylic acid during the reaction.

In this process, 2 H's are transferred to FAD and produce FADH₂. This energy carrier remains attached to the enzyme and transfers the electrons to the electron transport chain. The electron transport chain is a series of four enzyme complexes and two coenzymes:

• Complex I to Complex IV
• Coenzymes -ubiquinone and Cytochrome c

In the electron transport chain, ADP involves in the formation of ATP molecules in the mitochondria.

Interpretation Introduction

(d)

Interpretation:

The product formed from O₂ in the electron transport chain should be determined.

Concept Introduction:

Aerobic respiration occurs in two steps;

• Glycolysis
• Citric acid cycle

Glycolysis is the first step that forms pyruvate as given below:

  ${\text{Glucose + 2ATP + 2NAD}}^{\text{+}}{\text{ + 4ADP + 2P}}_{\text{i}}\stackrel{}{\to }{\text{ 2 Pyruvate + 4ATP + 2NADH + 2H}}^{\text{+}}$

In the presence of oxygen means aerobic respiration, this pyruvate enters in the Krebs cycle and extracts energy in the form of electrons transfer. Electrons are transferred from the pyruvate to the receptors like ${\text{NAD}}^{\text{+}}{\text{, GDP, and FAD and CO}}_{\text{2}}$ gas is formed as the waste product. The products of citric acid cycles act as precursors for electron transport chains.

Answer to Problem 23.58P

The electron transport chain process involves the pumping of the protons from the mitochondrial matrix to the intermembrane space that reduces the oxygen to a water molecule.

Explanation of Solution

The citric acid cycle is also known as the tricarboxylic acid cycle or Krebs cycles. In this cycle, all intermediates are carboxylate anions mainly which are formed from di or tricarboxylic acid during the reaction.

In this process, 2 H's are transferred to FAD and produce FADH₂. This energy carrier remains attached to the enzyme and transfers the electrons to the electron transport chain. The electron transport chain is a series of four enzyme complexes and two coenzymes:

• Complex I to Complex IV
• Coenzymes -ubiquinone and Cytochrome c

The electron transport chain is embedded in the inner mitochondrial membrane and it involves the shuffles in the electrons from NADH and FADH₂ to molecular oxygen.

The electron transport chain process involves the pumping of the protons from the mitochondrial matrix to the intermembrane space that reduces the oxygen to a water molecule.