Cellular Respiration Chemistry Worksheet Answer Key Explained

Understanding Cellular Respiration: A Chemistry Worksheet Answer Key Explained

Cellular respiration is a fundamental process in biology that involves the breakdown of glucose to produce energy for the cell. It is a complex process that involves multiple stages, including glycolysis, pyruvate oxidation, the citric acid cycle, and oxidative phosphorylation. In this article, we will provide a detailed explanation of the answer key to a cellular respiration chemistry worksheet, highlighting key concepts and equations.

Glycolysis: The First Stage of Cellular Respiration

Glycolysis is the first stage of cellular respiration, where glucose is converted into pyruvate. This stage occurs in the cytosol of the cell and does not require oxygen. The overall equation for glycolysis is:

C6H12O6 (glucose) + 2NAD+ + 2P + 2ADP → 2C3H4O3 (pyruvate) + 2NADH + 2H+ + 2ATP

The key steps in glycolysis are:

• Step 1: Glucose is converted into glucose-6-phosphate (G6P) using one ATP molecule.
• Step 2: G6P is converted into fructose-6-phosphate (F6P).
• Step 3: F6P is converted into fructose-1,6-bisphosphate (F1,6BP).
• Step 4: F1,6BP is converted into glyceraldehyde-3-phosphate (G3P) and dihydroxyacetone phosphate (DHAP).
• Step 5: G3P is converted into pyruvate, generating two ATP and two NADH molecules.

📝 Note: Glycolysis is an anaerobic process, meaning it does not require oxygen.

Pyruvate Oxidation: The Second Stage of Cellular Respiration

Pyruvate oxidation is the second stage of cellular respiration, where pyruvate is converted into acetyl-CoA. This stage occurs in the mitochondria and requires oxygen. The overall equation for pyruvate oxidation is:

C3H4O3 (pyruvate) + CoA + NAD+ → C2H3O (acetyl-CoA) + NADH + H+

The key steps in pyruvate oxidation are:

• Step 1: Pyruvate is converted into acetyl-CoA using one NAD+ molecule.
• Step 2: Acetyl-CoA is converted into citrate, entering the citric acid cycle.

The Citric Acid Cycle: The Third Stage of Cellular Respiration

The citric acid cycle, also known as the Krebs cycle or tricarboxylic acid cycle, is the third stage of cellular respiration. This stage occurs in the mitochondria and requires oxygen. The overall equation for the citric acid cycle is:

C2H3O (acetyl-CoA) + 3NAD+ + FAD + GDP + P + 2H2O → 2CO2 + 3NADH + FADH2 + GTP + 2H+

The key steps in the citric acid cycle are:

• Step 1: Acetyl-CoA is converted into citrate.
• Step 2: Citrate is converted into isocitrate.
• Step 3: Isocitrate is converted into α-ketoglutarate.
• Step 4: α-Ketoglutarate is converted into succinyl-CoA.
• Step 5: Succinyl-CoA is converted into succinate.
• Step 6: Succinate is converted into fumarate.
• Step 7: Fumarate is converted into malate.
• Step 8: Malate is converted into oxaloacetate.

📝 Note: The citric acid cycle is an aerobic process, meaning it requires oxygen.

Oxidative Phosphorylation: The Final Stage of Cellular Respiration

Oxidative phosphorylation is the final stage of cellular respiration, where energy is generated in the form of ATP. This stage occurs in the mitochondria and requires oxygen. The overall equation for oxidative phosphorylation is:

3NADH + FADH2 + 10H+ + 3ADP + 3P → 3ATP + 3NAD+ + FAD + 10H2O

The key steps in oxidative phosphorylation are:

• Step 1: NADH and FADH2 are converted into ATP using the electron transport chain.
• Step 2: Protons are pumped across the mitochondrial membrane, generating a proton gradient.
• Step 3: ATP synthase uses the proton gradient to generate ATP.

Cellular respiration is a complex process that involves multiple stages, each with its own unique equation and key steps. Understanding these stages is crucial for grasping the overall process of cellular respiration.

In conclusion, cellular respiration is a vital process that generates energy for the cell. By understanding the key stages and equations, students can better appreciate the complexity of this process.

Related Terms:

• Cellular respiration Worksheet pdf