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Cellular respiration worksheet

A free, printable worksheet for high school and AP Biology. Students follow one glucose through glycolysis, the citric acid cycle and the electron transport chain, explain how ATP synthase uses the proton gradient, and compare fermentation.

Download the PDF (free)Answer key (Teacher plan)

What's inside

  1. Vocabulary (10 terms)
  2. The stages (5 questions)
  3. The electron transport chain and ATP synthase (7 questions)
  4. Without oxygen (3 questions)

Teach it with the 3D lesson

Every question matches a step in CytoTour's 3D chapter on cellular respiration, built from real human protein structures. Read the steps with pictures on cellular respiration, step by step, or project the lesson in class — Chapter 1 is free, and the Teacher plan opens every chapter.

The worksheet

This is the printable sheet (16 questions). Printing this page prints only the worksheet.

CytoTour · cytotour.com · free to print and copy for your classes

Cellular respiration

NameDatePeriod

Part 1 · Vocabulary

1. Write the letter of the matching description next to each term.

  1. Glycolysis
  2. Citric acid cycle
  3. NADH
  4. Electron transport chain
  5. Oxygen
  6. Chemiosmosis
  7. ATP synthase
  8. Cristae
  9. Matrix
  10. Fermentation
  1. AFolds of the inner membrane that add surface area
  2. BCarrier that brings electrons to the electron transport chain
  3. CCycle in the mitochondrial matrix that releases CO₂ and makes NADH and FADH₂
  4. DThe final electron acceptor; it forms water
  5. EThe space inside the inner membrane, where the citric acid cycle happens
  6. FSplits one glucose into two pyruvate molecules, in the cytoplasm
  7. GProteins in the inner mitochondrial membrane that pass electrons along and pump protons
  8. HRegenerates NAD⁺ so glycolysis can continue without oxygen
  9. IMembrane enzyme whose rotor, turned by protons, makes ATP
  10. JProtons flowing back across the membrane drive the formation of ATP

Part 2 · The stages

2. Write the overall equation for the cellular respiration of glucose.

3. Where in a eukaryotic cell does each stage happen: glycolysis, the citric acid cycle, the electron transport chain?

4. Glycolysis uses 2 ATP and makes 4 ATP. What is its net gain of ATP per glucose?

  1. A2
  2. B4
  3. C6
  4. DZero — it only makes NADH

5. Each turn of the citric acid cycle releases 2 CO₂. How many CO₂ does the cycle release for one glucose?

  1. A2
  2. B4
  3. C6
  4. D1

6. Complete the table for one glucose.

CO₂ releasedNADH madeFADH₂ madeATP (net)
Glycolysis
Pyruvate → acetyl CoA (×2)
Citric acid cycle (2 turns)

Part 3 · The electron transport chain and ATP synthase

7. What is the final electron acceptor at the end of the electron transport chain?

  1. ANAD⁺
  2. BOxygen
  3. CCytochrome c
  4. DCarbon dioxide

8. Electrons from FADH₂ enter the chain at complex II. Why do they lead to fewer protons being pumped than electrons from NADH?

9. The chain has pumped protons out of the matrix. Where is the pH now higher?

  1. AIn the matrix
  2. BIn the intermembrane space
  3. CIt is the same on both sides
  4. DIn the cytoplasm only

10. Explain how the proton gradient across the inner membrane is used to make ATP.

11. Protons turn ATP synthase's rotor. How many ATP does one full 360° turn make?

  1. A1
  2. B3
  3. C8
  4. DAbout 30

12. One full turn of human ATP synthase moves 8 protons and makes 3 ATP. About how many protons does each ATP take?

13. About what share of the ATP from aerobic breakdown of glucose comes from chemiosmosis?

Part 4 · Without oxygen

14. Without oxygen, why do muscle cells and yeast ferment?

  1. ATo make more ATP than aerobic respiration
  2. BTo turn NADH back into NAD⁺ so glycolysis can keep going
  3. CTo make oxygen
  4. DTo keep the electron transport chain running

15. Name the product of fermentation in (a) human muscle cells short of oxygen and (b) yeast.

16. Without oxygen, how many ATP does a cell get from one glucose?