AP Biology Questions on Cellular Respiration: Preparing for the Exam

📚 Quick Study Guide

• ⚛️ Cellular respiration is the process by which cells convert glucose into ATP (adenosine triphosphate), the energy currency of the cell.
• 🔥 The overall reaction for cellular respiration is: $C_6H_{12}O_6 + 6O_2 \rightarrow 6CO_2 + 6H_2O + ATP$.
• ⚡ There are three main stages of cellular respiration:
  • 🍎 Glycolysis: Occurs in the cytoplasm and breaks down glucose into pyruvate.
  • 🍋 Krebs Cycle (Citric Acid Cycle): Occurs in the mitochondrial matrix and oxidizes pyruvate to $CO_2$.
  • 🔋 Oxidative Phosphorylation: Occurs in the inner mitochondrial membrane and uses the electron transport chain and chemiosmosis to produce ATP.
• NADH and $FADH_2$ are electron carriers that donate electrons to the electron transport chain.
• Chemiosmosis involves the movement of ions across a semipermeable membrane, down their electrochemical gradient. This process is used to generate ATP in mitochondria.
• Anaerobic respiration (fermentation) occurs in the absence of oxygen and produces less ATP than aerobic respiration.
  • 🍺 Alcoholic fermentation: Pyruvate is converted to ethanol.
  • 🥛 Lactic acid fermentation: Pyruvate is converted to lactic acid.

🧪 Practice Quiz

1. Which of the following is the primary purpose of cellular respiration?
   1. To produce glucose
   2. To break down proteins
   3. To generate ATP
   4. To synthesize amino acids
2. In which stage of cellular respiration is $CO_2$ produced?
   1. Glycolysis
   2. Electron Transport Chain
   3. Krebs Cycle
   4. Fermentation
3. Which molecule is the final electron acceptor in the electron transport chain?
   1. $H_2O$
   2. $CO_2$
   3. $O_2$
   4. NADH
4. Where does glycolysis take place in a eukaryotic cell?
   1. Mitochondrial matrix
   2. Inner mitochondrial membrane
   3. Cytoplasm
   4. Nucleus
5. What is the net ATP production from glycolysis?
   1. 4 ATP
   2. 36 ATP
   3. 2 ATP
   4. 38 ATP
6. Which type of fermentation occurs in human muscle cells during intense exercise?
   1. Alcoholic fermentation
   2. Lactic acid fermentation
   3. Acetic acid fermentation
   4. Citric acid fermentation
7. What role do NADH and $FADH_2$ play in oxidative phosphorylation?
   1. They directly synthesize ATP
   2. They donate electrons to the electron transport chain
   3. They accept electrons from the electron transport chain
   4. They transport pyruvate into the mitochondria