Cellular Respiration Review – Step-by-Step Study Guidance

Study Guide - Smart Notes

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

Q1. Draw a mitochondrion and label the mitochondrial matrix, inner membrane, and intermembrane space.

Background

Topic: Mitochondrial Structure

This question tests your understanding of the structure of mitochondria, which is essential for understanding where different stages of cellular respiration occur.

Key Terms:

Mitochondrial matrix: The innermost compartment, where the citric acid cycle occurs.
Inner membrane: The membrane with embedded proteins for the electron transport chain.
Intermembrane space: The space between the inner and outer mitochondrial membranes.

Step-by-Step Guidance

Draw an oval or bean-shaped outline to represent the mitochondrion.
Inside the outline, draw a highly folded inner membrane (cristae) to show increased surface area.
Label the space inside the inner membrane as the "mitochondrial matrix."
Label the area between the inner and outer membranes as the "intermembrane space."
Label the inner membrane itself, noting its role in the electron transport chain.

Try drawing and labeling before checking the answer!

Q2. List the four stages of aerobic cellular respiration in order, the location of each stage, and identify the major ATP producing phase.

Background

Topic: Stages of Cellular Respiration

This question tests your knowledge of the sequence, location, and ATP yield of the stages of aerobic respiration.

Key Terms:

Glycolysis
Pyruvate processing (Link reaction)
Citric Acid Cycle (Krebs Cycle)
Electron Transport Chain & Oxidative Phosphorylation

Step-by-Step Guidance

Recall the order of the four main stages of aerobic respiration.
For each stage, identify its specific location within the cell (e.g., cytosol, mitochondrial matrix, inner mitochondrial membrane).
Determine which stage produces the most ATP and circle it.
Write the name and location for each stage in order.

Try to fill in the stages and locations before checking the answer!

Q3. What are the inputs of glycolysis?

Background

Topic: Glycolysis Inputs

This question checks your understanding of what molecules are required to start glycolysis, the first step of cellular respiration.

Key Terms:

Glucose
ATP
NAD+
ADP + Pi

Step-by-Step Guidance

Recall the main substrate that enters glycolysis.
Think about the energy investment phase—what energy molecule is used?
Consider what electron carrier is reduced during glycolysis.
List all the molecules that must be present for glycolysis to proceed.

Try listing the inputs before checking the answer!

Q4. Why are the first steps of glycolysis called the “investment” phase?

Background

Topic: Glycolysis Phases

This question tests your understanding of why ATP is consumed early in glycolysis.

Key Terms:

Investment phase: The initial steps where ATP is used to phosphorylate glucose.

Step-by-Step Guidance

Recall what happens to glucose in the first steps of glycolysis.
Think about why ATP is used before any is produced.
Explain how this prepares glucose for later steps in glycolysis.

Try explaining the investment phase before checking the answer!

Q5. What are the outputs of glycolysis?

Background

Topic: Glycolysis Outputs

This question checks your knowledge of the products formed at the end of glycolysis.

Key Terms:

Pyruvate
ATP
NADH

Step-by-Step Guidance

Recall how many molecules of pyruvate are produced from one glucose.
Think about the net gain of ATP in glycolysis.
Consider how many NADH molecules are generated.
List all the outputs of glycolysis.

Try listing the outputs before checking the answer!

Q6. Why are the last steps of glycolysis called the “payoff” phase?

Background

Topic: Glycolysis Phases

This question tests your understanding of ATP and NADH production in the later steps of glycolysis.

Key Terms:

Payoff phase: The steps where ATP and NADH are produced.

Step-by-Step Guidance

Recall what is produced in the second half of glycolysis.
Think about how this phase contrasts with the investment phase.
Explain why this phase is considered the "payoff."

Try explaining the payoff phase before checking the answer!

Q7. After glycolysis is complete, where is most of the energy that was in glucose?

Background

Topic: Energy Flow in Glycolysis

This question tests your understanding of energy transfer during glycolysis.

Key Terms:

Pyruvate
NADH

Step-by-Step Guidance

Consider what happens to the carbon atoms of glucose after glycolysis.
Think about the energy content of the products formed.
Identify which molecule(s) still contain most of the original energy from glucose.

Try identifying where the energy is before checking the answer!

Q8. During the process of glycolysis, has the process of the oxidation of glucose started? If so, how can you tell?

Background

Topic: Oxidation in Glycolysis

This question tests your understanding of redox reactions during glycolysis.

Key Terms:

Oxidation: Loss of electrons (often as hydrogen atoms).
NAD+ reduction to NADH

Step-by-Step Guidance

Recall what happens to glucose during glycolysis in terms of electron transfer.
Think about the role of NAD+ in glycolysis.
Explain how you can tell if oxidation has occurred based on the products formed.

Try explaining the evidence for oxidation before checking the answer!

Q9. What 3-carbon sugar is an input of pyruvate processing? How many per glucose?

Background

Topic: Pyruvate Processing Inputs

This question checks your knowledge of the molecules entering the next stage after glycolysis.

Key Terms:

Pyruvate

Step-by-Step Guidance

Recall the end product of glycolysis.
Determine how many molecules of this 3-carbon compound are produced per glucose molecule.

Try answering before checking the answer!

Q10. Is the 3-carbon sugar that enters pyruvate processing being oxidized? If so, how can you tell?

Background

Topic: Oxidation in Pyruvate Processing

This question tests your understanding of redox changes during pyruvate processing.

Key Terms:

Oxidation
NAD+ reduction
CO2 release

Step-by-Step Guidance

Recall what happens to pyruvate during its processing in the mitochondria.
Think about whether electrons are lost or gained by pyruvate.
Identify the evidence for oxidation (e.g., electron carrier reduction, CO2 release).

Try explaining before checking the answer!

Q11. What is being released as a by-product of the breakdown of the 3-carbon sugar in pyruvate processing?

Background

Topic: By-products of Pyruvate Processing

This question checks your knowledge of the fate of carbon atoms during pyruvate processing.

Key Terms:

CO2 (carbon dioxide)

Step-by-Step Guidance

Recall what happens to one carbon atom from pyruvate during processing.
Think about the gaseous by-product released in this step.

Try answering before checking the answer!

Q12. When the 3-carbon sugar is broken down in pyruvate processing, a 2-carbon ____________ is the product. How many are produced per glucose?

Background

Topic: Products of Pyruvate Processing

This question tests your understanding of the conversion of pyruvate to a 2-carbon molecule.

Key Terms:

Acetyl group (acetyl-CoA)

Step-by-Step Guidance

Recall what the 3-carbon pyruvate is converted into during processing.
Determine how many of these 2-carbon molecules are produced per glucose molecule.

Try filling in the blanks before checking the answer!

Q13. What gets added to the output of pyruvate processing (#12 above)? What is the purpose of this molecule?

Background

Topic: Coenzyme A in Pyruvate Processing

This question checks your understanding of the role of coenzymes in cellular respiration.

Key Terms:

Coenzyme A (CoA)

Step-by-Step Guidance

Recall what molecule binds to the acetyl group after pyruvate processing.
Explain the function of this molecule in the citric acid cycle.

Try answering before checking the answer!

Q14. Is ATP produced in pyruvate processing?

Background

Topic: ATP Yield in Pyruvate Processing

This question tests your knowledge of energy production during the link reaction.

Key Terms:

ATP

Step-by-Step Guidance

Recall the main products of pyruvate processing.
Determine if ATP is one of the products in this stage.

Try answering before checking the answer!

Q15. What molecule from pyruvate processing enters the Citric Acid Cycle? How many per glucose?

Background

Topic: Citric Acid Cycle Inputs

This question checks your understanding of the molecules entering the Krebs cycle.

Key Terms:

Acetyl-CoA

Step-by-Step Guidance

Recall the product of pyruvate processing that is used in the citric acid cycle.
Determine how many of these molecules are produced per glucose molecule.

Try answering before checking the answer!

Q16. What is being released as a by-product of the breakdown of the 2-carbon sugar product in the citric acid cycle? How many per glucose?

Background

Topic: By-products of the Citric Acid Cycle

This question tests your understanding of carbon flow and by-products in the Krebs cycle.

Key Terms:

CO2 (carbon dioxide)

Step-by-Step Guidance

Recall what happens to the acetyl group in the citric acid cycle.
Determine how many CO2 molecules are released per glucose molecule.

Try answering before checking the answer!

Q17. Are the acetyl groups being oxidized in the citric acid cycle? If so, list the numbers and types of reduced electron carriers produced in this step per glucose:

Background

Topic: Oxidation and Electron Carriers in the Citric Acid Cycle

This question checks your understanding of redox reactions and electron carrier production in the Krebs cycle.

Key Terms:

NADH
FADH2

Step-by-Step Guidance

Recall what happens to acetyl groups in the citric acid cycle.
List the types of electron carriers that are reduced during this cycle.
Determine how many of each are produced per glucose molecule.

Try listing the electron carriers before checking the answer!

Q18. Compare the number of reduced electron carriers in the first three stages of aerobic cellular respiration. Why is the citric acid cycle called the MAJOR oxidation stage?

Background

Topic: Electron Carrier Production

This question tests your ability to compare the output of NADH and FADH2 in glycolysis, pyruvate processing, and the citric acid cycle.

Key Terms:

NADH
FADH2
Oxidation

Step-by-Step Guidance

List the number of NADH and FADH2 produced in glycolysis, pyruvate processing, and the citric acid cycle.
Compare the totals for each stage.
Explain why the citric acid cycle is considered the major oxidation stage.

Try comparing the numbers before checking the answer!

Q19. Are any ATP produced in the citric acid cycle? If so, how many per glucose?

Background

Topic: ATP Yield in the Citric Acid Cycle

This question checks your knowledge of substrate-level phosphorylation in the Krebs cycle.

Key Terms:

ATP (or GTP)

Step-by-Step Guidance

Recall if ATP (or GTP) is produced directly in the citric acid cycle.
Determine how many molecules are produced per glucose molecule.

Try answering before checking the answer!

Q20. Complete the following summary table with numbers:

Background

Topic: Cellular Respiration Summary Table

This question tests your ability to summarize the inputs and outputs of each stage of cellular respiration.

Key Terms:

Glycolysis
Pyruvate Processing
Citric Acid Cycle
ATP, NADH, FADH2, CO2

Step-by-Step Guidance

For each stage, recall the main sugar input and output.
List the number of reduced electron carriers (NADH, FADH2) produced.
List the number of ATP and CO2 molecules produced.
Fill in the table with the correct numbers for each stage.

Try completing the table before checking the answer!

Q21. After the citric acid cycle, what is “holding” the energy harvested from glucose?

Background

Topic: Energy Carriers

This question checks your understanding of where the energy from glucose is stored after the citric acid cycle.

Key Terms:

NADH
FADH2

Step-by-Step Guidance

Recall what molecules are produced in large quantities during the citric acid cycle.
Think about which molecules will donate electrons to the electron transport chain.

Try answering before checking the answer!

Q22. Where do all of the reduced electron carriers drop off their high energy electrons? Where in the mitochondria is it embedded?

Background

Topic: Electron Transport Chain Location

This question tests your understanding of where NADH and FADH2 deliver electrons and the location of the electron transport chain.

Key Terms:

Electron Transport Chain (ETC)
Inner mitochondrial membrane

Step-by-Step Guidance

Recall the final destination for electrons from NADH and FADH2.
Identify the specific mitochondrial structure where the ETC is located.

Try answering before checking the answer!

Q23. NADH drops its high energy electrons off at the first protein complex and FADH2 drops its high energy electrons off at the second protein complex of the electron transport chain. Why do the electrons get pulled down the chain? What by-product forms as a result?

Background

Topic: Electron Flow and By-products in ETC

This question tests your understanding of the driving force for electron movement and the formation of water as a by-product.

Key Terms:

Electronegativity
Oxygen
Water (H2O)

Step-by-Step Guidance

Recall why electrons move from one complex to the next in the ETC.
Identify the final electron acceptor and the by-product formed.

Try explaining before checking the answer!

Q24. Explain why oxygen is said to be the final electron acceptor in aerobic cellular respiration.

Background

Topic: Oxygen's Role in ETC

This question tests your understanding of the importance of oxygen in the electron transport chain.

Key Terms:

Final electron acceptor
Water formation

Step-by-Step Guidance

Recall what happens to electrons at the end of the ETC.
Explain why oxygen is necessary for aerobic respiration to continue.

Try explaining before checking the answer!

Q25. As the electrons move down the electron transport chain, what do they give off? What do most of the protein complexes in the electron transport chain do in response? What kind of transport is this (active or passive)?

Background

Topic: Proton Gradient Formation

This question tests your understanding of how the ETC creates a proton gradient and the type of transport involved.

Key Terms:

Proton (H+) pumping
Active transport

Step-by-Step Guidance

Recall what happens to the energy released as electrons move through the ETC.
Explain how this energy is used by protein complexes in the inner mitochondrial membrane.
Identify the type of transport involved in moving protons across the membrane.

Try explaining before checking the answer!

Q26. As a result of the action in the question above (#25), _ accumulate in the ___ (part of mitochondria)? They then diffuse across the membrane into the mitochondrial _ through what enzyme? What is this facilitated called?

Background

Topic: Chemiosmosis and ATP Synthase

This question tests your understanding of proton movement and ATP synthesis.

Key Terms:

Proton gradient
ATP synthase
Chemiosmosis

Step-by-Step Guidance

Recall where protons accumulate as a result of ETC activity.
Identify the enzyme that allows protons to flow back into the mitochondrial matrix.
Name the process by which ATP is synthesized as protons flow through this enzyme.

Try filling in the blanks before checking the answer!

Q27. Why can’t protons (H+) diffuse directly across the membrane?

Background

Topic: Membrane Permeability

This question tests your understanding of the properties of the inner mitochondrial membrane.

Key Terms:

Phospholipid bilayer
Charge and polarity

Step-by-Step Guidance

Recall the structure of the inner mitochondrial membrane.
Explain why charged particles like protons cannot pass through the lipid bilayer unaided.

Try explaining before checking the answer!

Q28. As a result of chemiosmosis, the enzyme spins producing ______ (#) of ATP per glucose. What is this process of making ATP called?

Background

Topic: ATP Yield and Oxidative Phosphorylation

This question tests your knowledge of the amount of ATP produced and the name of the process.

Key Terms:

ATP synthase
Oxidative phosphorylation

Step-by-Step Guidance

Recall the approximate number of ATP molecules produced per glucose via chemiosmosis.
Name the process by which ATP is synthesized using the proton gradient.

Try answering before checking the answer!

Q29. Predict the consequence to ATP production if a cell placed multiple proton channels in the inner mitochondrial membrane. Explain.

Background

Topic: Proton Gradient Disruption

This question tests your understanding of the importance of maintaining the proton gradient for ATP synthesis.

Key Terms:

Proton leak
ATP synthase

Step-by-Step Guidance

Consider what would happen to the proton gradient if protons could flow freely across the membrane.
Explain how this would affect the function of ATP synthase and ATP production.

Try predicting the consequence before checking the answer!

Q30. Predict the consequence to ATP production if oxygen were replaced by a less electronegative atom like nitrogen in the electron transport chain?

Background

Topic: Electron Acceptors in ETC

This question tests your understanding of the role of oxygen's electronegativity in driving the ETC.

Key Terms:

Electronegativity
Electron flow

Step-by-Step Guidance

Recall why oxygen is an effective final electron acceptor.
Predict what would happen to electron flow and ATP production if a less electronegative atom were used instead.

Try predicting the consequence before checking the answer!

Q31. For aerobic cellular respiration to continue (additional glucose to be oxidized), what important molecule must be recycled?

Background

Topic: Electron Carrier Recycling

This question tests your understanding of the need to regenerate electron carriers for continued respiration.

Key Terms:

NAD+
FAD

Step-by-Step Guidance

Recall which molecules accept electrons during glycolysis and the citric acid cycle.
Identify which must be regenerated for these processes to continue.

Try answering before checking the answer!

Q32. In the presence of oxygen, how are these molecules recycled?

Background

Topic: Electron Carrier Regeneration

This question tests your understanding of how NAD+ and FAD are regenerated in aerobic respiration.

Key Terms:

Electron transport chain
Oxygen as final electron acceptor

Step-by-Step Guidance

Recall what happens to NADH and FADH2 in the electron transport chain.
Explain how this process regenerates NAD+ and FAD.

Try explaining before checking the answer!

Q33. In low oxygen levels, some types of cells give their electrons back to the end-product of glycolysis – _______________. What by-product is formed as a result in yeast cells? Animal muscle cells? What is this process called?

Background

Topic: Fermentation

This question tests your understanding of anaerobic pathways and their products.

Key Terms:

Fermentation
Lactic acid
Ethanol

Step-by-Step Guidance

Recall what molecule receives electrons from NADH in the absence of oxygen.
Identify the by-products formed in yeast and animal muscle cells.
Name the process that allows glycolysis to continue in low oxygen.

Try filling in the blanks before checking the answer!

Q34. What stage of cellular respiration can occur in the presence or absence of oxygen in yeast and animal muscle cells?

Background

Topic: Anaerobic and Aerobic Pathways

This question tests your understanding of which steps of cellular respiration are oxygen-independent.

Key Terms:

Glycolysis

Step-by-Step Guidance

Recall which stage of cellular respiration does not require oxygen.
Identify if this stage occurs in both aerobic and anaerobic conditions.

Try answering before checking the answer!

Q35. How does the yield of ATP in low oxygen compare to aerobic cellular respiration per glucose?

Background

Topic: ATP Yield Comparison

This question tests your understanding of the efficiency of fermentation versus aerobic respiration.

Key Terms:

ATP yield
Fermentation

Step-by-Step Guidance

Recall the number of ATP produced per glucose in aerobic respiration.
Recall the number of ATP produced per glucose in fermentation.
Compare the two values.

Try comparing the yields before checking the answer!

Q36. The flow of electrons is from the initial sugar ____ to _(carriers) to via the electron transport chain to produce _______.

Background

Topic: Electron Flow in Cellular Respiration

This question tests your ability to trace the path of electrons from glucose to the final product.

Key Terms:

Glucose
NADH/FADH2
Oxygen
Water

Step-by-Step Guidance

Recall the sequence of electron flow from glucose through carriers to the final acceptor.
Fill in the blanks with the correct molecules.

Try tracing the flow before checking the answer!

Q37. Energy in the sugar ___________ is removed as high energy _ and given to ____ who bring the high energy to the _ _ chain where the energy is used to power protein _ to form a high energy proton gradient. The high potential energy protons diffuse across _ (enzyme). The potential energy of the proton gradient is converted into spinning or energy, which is then converted into energy as ATP.

Background

Topic: Energy Flow in Cellular Respiration

This question tests your ability to trace the flow of energy from glucose to ATP.

Key Terms:

Glucose
Electrons
NADH/FADH2
Electron transport chain
ATP synthase
Chemical, mechanical, and chemical energy

Step-by-Step Guidance

Follow the path of energy from glucose to ATP, filling in each blank with the appropriate term.
Think about the forms of energy conversion at each step.

Try tracing the energy flow before checking the answer!

Q38. Trace the flow of carbon: 6C: ____ 2x3C: _ 2x2C: _____

Background

Topic: Carbon Flow in Cellular Respiration

This question tests your ability to track carbon atoms from glucose through the stages of respiration.

Key Terms:

Glucose
Pyruvate
Acetyl-CoA

Step-by-Step Guidance

Recall the number of carbons in glucose, pyruvate, and acetyl-CoA.
Fill in the blanks with the correct molecules at each stage.