Skip to main content
Back

Biology 111 Exam 3 Study Guide: Cellular Respiration, Mitosis & Meiosis, Inheritance, and DNA Structure

NotesPracticeVideo lessons

Study Guide - Smart Notes

Tailored notes based on your materials, expanded with key definitions, examples, and context.

Q1. What kind of energy change is associated with the citric acid cycle? (Is it endergonic or exergonic?)

Background

Topic: Cellular Respiration – Citric Acid Cycle (Krebs Cycle)

This question tests your understanding of the energy transformations that occur during the citric acid cycle, a key metabolic pathway in cellular respiration.

Key Terms

  • Endergonic: A reaction that requires energy input.

  • Exergonic: A reaction that releases energy.

  • Citric Acid Cycle: Also known as the Krebs cycle; a series of chemical reactions used by all aerobic organisms to generate energy.

Step-by-Step Guidance

  1. Recall that the citric acid cycle is part of cellular respiration, which is the process cells use to extract energy from nutrients.

  2. Think about whether the cycle as a whole releases energy or requires energy input. Consider what happens to the high-energy electrons and the production of ATP, NADH, and FADH2.

  3. Remember that the products of the cycle are used to generate more ATP in the electron transport chain, indicating the direction of energy flow.

Try solving on your own before revealing the answer!

Q2. Know the stages of Respiration: Glycolysis, Pyruvate oxidation, Krebs Cycle, and the ETC. Know what is added to the cycle (ATP, NAD+, etc.) and what comes out.

Background

Topic: Cellular Respiration Pathways

This question tests your ability to identify the main stages of cellular respiration and the key inputs and outputs of each stage.

Key Terms

  • Glycolysis: The breakdown of glucose into pyruvate.

  • Pyruvate Oxidation: Conversion of pyruvate to acetyl-CoA.

  • Krebs Cycle (Citric Acid Cycle): Series of reactions generating NADH, FADH2, and ATP.

  • Electron Transport Chain (ETC): Uses electrons from NADH and FADH2 to produce ATP.

Step-by-Step Guidance

  1. List the four main stages of cellular respiration in order: Glycolysis, Pyruvate Oxidation, Krebs Cycle, and Electron Transport Chain.

  2. For each stage, identify the main reactants (what goes in) and products (what comes out). For example, glycolysis uses glucose and produces pyruvate, ATP, and NADH.

  3. Consider the role of electron carriers (NAD+, FAD) and ATP in each stage.

  4. Think about where each stage occurs in the cell (cytoplasm or mitochondria).

Try solving on your own before revealing the answer!

Q3. Be able to label the diagram of the cycle with the reactants and products.

Background

Topic: Cellular Respiration – Krebs Cycle Diagram

This question tests your ability to visually identify and label the key molecules involved in the Krebs cycle.

Key Terms

  • Reactants: Molecules that enter a reaction (e.g., Acetyl-CoA, NAD+).

  • Products: Molecules produced (e.g., CO2, NADH, FADH2, ATP).

Step-by-Step Guidance

  1. Review a diagram of the Krebs cycle and identify the entry point (Acetyl-CoA).

  2. Label where NAD+, FAD, and GDP/ADP are used, and where NADH, FADH2, GTP/ATP, and CO2 are produced.

  3. Note the cyclical nature of the pathway and how oxaloacetate is regenerated.

Try solving on your own before revealing the answer!

Q4. Where does each stage of cellular respiration happen?

Background

Topic: Cellular Respiration – Cellular Compartments

This question tests your knowledge of cell structure and the localization of metabolic pathways.

Key Terms

  • Cytoplasm: Fluid inside the cell where glycolysis occurs.

  • Mitochondria: Organelle where pyruvate oxidation, Krebs cycle, and ETC occur.

Step-by-Step Guidance

  1. List each stage of cellular respiration: Glycolysis, Pyruvate Oxidation, Krebs Cycle, Electron Transport Chain.

  2. Recall the specific location for each stage (e.g., cytoplasm, mitochondrial matrix, inner mitochondrial membrane).

  3. Think about why compartmentalization is important for these processes.

Try solving on your own before revealing the answer!

Q5. Why is it important that the electrons are passed down the electron transport chain?

Background

Topic: Cellular Respiration – Electron Transport Chain (ETC)

This question tests your understanding of how the ETC generates ATP and why electron transfer is crucial.

Key Terms

  • Electron Transport Chain: Series of protein complexes that transfer electrons and pump protons.

  • ATP Synthesis: The process of making ATP using the energy from a proton gradient.

Step-by-Step Guidance

  1. Recall that electrons from NADH and FADH2 are transferred through the ETC.

  2. Consider how this electron flow is coupled to proton pumping across the inner mitochondrial membrane.

  3. Think about how the resulting proton gradient is used to drive ATP synthesis via ATP synthase.

Try solving on your own before revealing the answer!

Q6. Why does your respiration rate increase when you are exercising (explain in context of the citric acid cycle)?

Background

Topic: Cellular Respiration and Exercise Physiology

This question tests your understanding of metabolic demand and the role of the citric acid cycle during increased activity.

Key Terms

  • Respiration Rate: The number of breaths per minute.

  • ATP Demand: The need for more energy during exercise.

  • Citric Acid Cycle: Central pathway for energy production.

Step-by-Step Guidance

  1. Consider how muscle activity increases the demand for ATP.

  2. Think about how the citric acid cycle responds to increased substrate (acetyl-CoA) and oxygen availability.

  3. Relate increased respiration rate to the need for more oxygen to support the citric acid cycle and ETC.

Try solving on your own before revealing the answer!

Q7. What is an electron acceptor and why does it accept an electron? What does the electron acceptor do with the electron?

Background

Topic: Redox Reactions in Cellular Respiration

This question tests your understanding of electron carriers and their role in energy transfer.

Key Terms

  • Electron Acceptor: A molecule that gains electrons during a redox reaction.

  • Redox Reaction: Chemical reaction involving the transfer of electrons.

Step-by-Step Guidance

  1. Define what an electron acceptor is in the context of cellular respiration (e.g., NAD+, FAD, O2).

  2. Explain why electron acceptors are necessary for the flow of electrons and energy extraction.

  3. Describe what happens to the electron after it is accepted (e.g., used to form water, generate ATP).

Try solving on your own before revealing the answer!

Q8. What is oxygen used for during cellular respiration? Why do you need oxygen to live?

Background

Topic: Role of Oxygen in Cellular Respiration

This question tests your understanding of oxygen's role as the final electron acceptor in the electron transport chain.

Key Terms

  • Final Electron Acceptor: The molecule that receives electrons at the end of the ETC (oxygen in aerobic respiration).

  • Water Formation: Oxygen combines with electrons and protons to form water.

Step-by-Step Guidance

  1. Recall that oxygen is required at the end of the electron transport chain.

  2. Explain what happens if oxygen is not present (e.g., backup of electrons, halt in ATP production).

  3. Describe why this process is essential for life in aerobic organisms.

Try solving on your own before revealing the answer!

Q9. What does one glucose molecule make throughout the Citric Acid cycle (hint: the cycle runs 2x for each glucose)?

Background

Topic: Citric Acid Cycle Yield per Glucose

This question tests your ability to calculate the total products generated from one glucose molecule during the citric acid cycle.

Key Terms

  • Glucose: A six-carbon sugar that is split into two pyruvate molecules.

  • Citric Acid Cycle: Each glucose yields two turns of the cycle.

Step-by-Step Guidance

  1. Recall that one glucose produces two pyruvate molecules, each entering the citric acid cycle.

  2. List the products generated per turn of the cycle (e.g., NADH, FADH2, ATP/GTP, CO2).

  3. Multiply the per-cycle yield by two to get the total per glucose molecule.

Try solving on your own before revealing the answer!

Q10. Anaerobic and aerobic respiration: how do they differ? What are the differences between fermentation and the lactic acid cycle?

Background

Topic: Types of Respiration and Fermentation

This question tests your understanding of the differences between aerobic and anaerobic pathways, and between fermentation types.

Key Terms

  • Aerobic Respiration: Uses oxygen as the final electron acceptor.

  • Anaerobic Respiration: Does not use oxygen; uses other molecules as electron acceptors.

  • Fermentation: Process that allows glycolysis to continue in the absence of oxygen.

  • Lactic Acid Cycle: Produces lactic acid as a byproduct.

Step-by-Step Guidance

  1. Define aerobic and anaerobic respiration and identify their key differences (e.g., oxygen use, ATP yield).

  2. Explain what fermentation is and how it differs from the lactic acid cycle.

  3. List the products of each process and their significance for the cell.

Try solving on your own before revealing the answer!

Q11. What is the function of cellular respiration? Write out the basic formula and list why each reactant is necessary.

Background

Topic: Cellular Respiration Overview

This question tests your understanding of the overall purpose of cellular respiration and the chemical equation involved.

Key Formula

Key Terms

  • Glucose (C6H12O6): Main fuel molecule.

  • Oxygen (O2): Final electron acceptor.

  • ATP: Main energy currency of the cell.

Step-by-Step Guidance

  1. Write out the overall equation for cellular respiration.

  2. Identify each reactant and product in the equation.

  3. Explain the role of each reactant (e.g., glucose as energy source, oxygen for electron acceptance).

Try solving on your own before revealing the answer!

Pearson Logo

Study Prep