With and without oxygen: respiration and fermentation
Grade 9 Science Worksheet - Building Confidence
Circle the best answer.
Read this first
Use this
Flow diagram (model, not to scale), drawn across a cell. Input box on the left: 1 glucose. Stage 1, in the cytoplasm: glycolysis makes 2 pyruvate. The path then splits. Branch A, oxygen absent: fermentation in the cytoplasm. Branch B, oxygen present: pyruvate enters the mitochondrion.
Ari reads a flow diagram of a cell with no oxygen. After glycolysis, which branch runs?
- Both branches, because pyruvate has to use each one
- Neither branch, because a cell with no oxygen makes no ATP
- Branch B, because fermentation needs oxygen to run
- Branch A, because fermentation does not need oxygen
Bo reads a flow diagram of a cell with plenty of oxygen. After glycolysis, which branch runs, and where?
- Branch A, in the cytoplasm, where glycolysis happens
- Branch B, in the mitochondrion, since fermentation comes first
- Branch A, in the mitochondrion
- Branch B, in the cytoplasm, because fermentation uses the oxygen
Jun reads a reaction in a muscle cell low on oxygen: pyruvate + NADH → A + NAD+. What goes in box A?
- Carbon dioxide, released as a gas
- Lactate, also called lactic acid
- ATP, made by the fermentation step
- NADH, made again from the NAD+
Flow diagram (model, not to scale). No wavy arrow is drawn. Kira reads about yeast in bread dough. The yeast ferment sugar and release gas A, which makes the dough rise. Name gas A.
- Oxygen gas (O2) from the air
- Lactic acid, a liquid from the sugar
- Carbon dioxide gas (CO2)
- Hydrogen gas (H2) from the sugar
The words are aerobic respiration. Four meanings are listed in the choices. Milo matches the words aerobic respiration to their meaning. Which meaning is right?
- A way to turn NADH back into NAD+ with pyruvate
- Respiration that makes ATP without using any oxygen
- Respiration that uses oxygen as the final electron acceptor
- Respiration that nets about 2 ATP per glucose in total
The word is fermentation. Four jobs are listed in the choices. Noah matches the word fermentation to its job in a cell. Which job is right?
- Making NADH so the cell has more electron carriers
- Making most of the cell's ATP after glycolysis
- Turning NADH back into NAD+ so glycolysis can continue
- Using oxygen to finish breaking down the pyruvate
The word is anaerobic, on a card about mud. Four meanings are listed in the choices. Pia sees the word anaerobic on a card about mud. What does anaerobic describe?
- A process found in yeast cells alone
- A process that cannot make any ATP
- A process that needs oxygen to get started
- A process that runs without oxygen
ATP card (sourced values)
path ATP in total per 1 glucose Aerobic respiration about 30 Fermentation 2 Ren reads the ATP card. How many ATP does fermentation make in total from 1 glucose?
- 4 ATP
- 0 ATP
- 2 ATP
- about 30 ATP
Cell card (model data)
cell oxygen ATP in total Cell P present about 30 Cell Q absent 2 Tala reads a card of two cells that each start with 1 glucose. Which cell makes more ATP in total?
- Cell Q, because fermentation makes more ATP
- Neither, because the two cells make the same
- Cell P, with about 30 ATP
- Cell P, with about 2 ATP, since oxygen cells make less
Use this
Flow diagram (model, not to scale), drawn in the cytoplasm. Input box on the left: 1 glucose. Output boxes on the right: 2 pyruvate; net 2 ATP; B NADH, where B is a blank number.
Zee reads the glycolysis box. How many NADH does glycolysis make from 1 glucose?
- 0 NADH, because NADH is made in the mitochondrion
- 2 NADH, one for each pyruvate
- 1 NADH, one for each glucose
- 4 NADH, two for each pyruvate