Cellular respiration: the equation and its three stages
Grade 9 Science Worksheet - Building Confidence
Circle the best answer.
“model, not to scale” Ari reads a diagram of one stage of breaking down glucose. In box A, 1 glucose is split into 2 pyruvate. Where in the cell does stage A happen?
- In the cytoplasm
- In the mitochondrial matrix
- On the inner mitochondrial membrane
- In the nucleus
Flow diagram (model, not to scale), drawn across a cell with one mitochondrion. No wavy arrow label is drawn. Bo reads a diagram of the citric acid cycle. In box B, an acetyl group joins a four-carbon molecule and CO2 is released. Where does stage B happen?
- In the mitochondrial matrix
- In the cytoplasm outside the mitochondrion
- On the inner mitochondrial membrane
- On a ribosome next to the nucleus
Read this first
Use this
Flow diagram (model, not to scale), drawn across a cell with one mitochondrion. Inputs in boxes on the left: electrons from NADH; oxygen. Outputs in boxes on the right: water. Box C is the chain of proteins. A wavy arrow points out: energy used to make ATP.
Esme reads that oxygen is used at box C, a chain of proteins that passes electrons along. Where is this electron transport chain found?
- In the cytoplasm outside the mitochondrion
- In the matrix inside the mitochondrion
- On the inner mitochondrial membrane
- In a vacuole near the cell membrane
Equation card, from OpenStax Biology 2e
C6H12O6 + 6O2 → 6CO2 + 6H2O + energy. Inputs in boxes on the left: glucose, C6H12O6; oxygen, 6O2. Outputs in boxes on the right: carbon dioxide, 6CO2; water, 6H2O. A wavy arrow points out: energy. The cell is a leaf cell kept in the dark.
Jun reads that a leaf cell kept in the dark breaks down glucose to make ATP. Which two things does the respiration equation show going in?
- Light and carbon dioxide
- Glucose and carbon dioxide
- Carbon dioxide and water
- Glucose and oxygen
Equation card, from OpenStax Biology 2e
C6H12O6 + 6O2 → 6CO2 + 6H2O + energy. Inputs in boxes on the left: glucose, C6H12O6; oxygen, 6O2. Outputs in boxes on the right: carbon dioxide, 6CO2; water, 6H2O. A wavy arrow points out: energy.
Kira reads the respiration equation. How many oxygen molecules, O2, does the equation use for each glucose?
- 12, the count of oxygen atoms instead
- 2, the small number after the O
- 6, the large number in front of the O2
- 1, the same count as the glucose
Flow diagram (model, not to scale), drawn on the inner membrane of a mitochondrion. Luz follows oxygen to the last stage. Oxygen picks up electrons and hydrogen ions at the end of the chain. What product forms in box D?
- Water, H2O
- Glucose, C6H12O6
- Pyruvate, from glycolysis
- Carbon dioxide, CO2
Flow diagram (model, not to scale), drawn across a cell. Milo hears that cells carry out cellular respiration. Which phrase tells what cellular respiration means?
- Making glucose from light, water and carbon dioxide
- Using glucose and oxygen in cells to make ATP
- Breathing air in and out through the lungs
- Making new energy inside the cell from nothing
Glycolysis ATP count (real data, from OpenStax Biology 2e)
measure ATP per glucose ATP spent 2 ATP made 4 Noah reads that glycolysis spends 2 ATP and makes 4 ATP from one glucose. Which phrase describes the ATP glycolysis adds for the cell?
- A small net gain of 2 ATP per glucose
- A net gain of 4 ATP, with nothing spent
- Most of the ATP made from one glucose
- ATP made by the electron transport chain
Ren reads a chart of where the ATP from glucose is made. Blank box D makes about 90 percent of the ATP. Which label fits D?
- Chemiosmosis on the inner membrane
- The citric acid cycle in the matrix
- Pyruvate oxidation in the matrix
- Glycolysis in the cytoplasm
No wavy arrow label is drawn. Zee sees pyruvate broken down in the mitochondrial matrix, with a gas leaving at box G. The gas is made from pyruvate's carbon. Which label fits G?
- Oxygen, the same gas the cell took in
- Glucose, rebuilt from the pyruvate
- Carbon dioxide, with carbon from pyruvate
- Water vapor, formed from the pyruvate
