With and without oxygen: respiration and fermentation
Grade 9 Science Worksheet - Building Confidence
Circle the best answer.
Bo reads a flow diagram of a cell with plenty of oxygen. After glycolysis, which branch runs, and where?
- Branch B, in the cytoplasm, because fermentation uses the oxygen
- Branch A, in the cytoplasm, where glycolysis happens
- Branch B, in the mitochondrion, since fermentation comes first
- Branch A, in the mitochondrion
Read this first
Use this
Flow diagram (model, not to scale), drawn across a cell. Input box on the left: 1 glucose. Stage A turns 1 glucose into 2 pyruvate, with a net of 2 ATP. Then branch 1 (oxygen present) and branch 2 (oxygen absent) both start from the pyruvate.
Esme sees stage A at the start of both branches. In stage A, 1 glucose becomes 2 pyruvate. Name stage A and its place.
- Glycolysis, in the cytoplasm
- Glycolysis, in the mitochondrion
- Fermentation, in the mitochondrion
- Fermentation, in the cytoplasm
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
- NADH, made again from the NAD+
- Lactate, also called lactic acid
- ATP, made by the fermentation step
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.
- Hydrogen gas (H2) from the sugar
- Carbon dioxide gas (CO2)
- Oxygen gas (O2) from the air
- Lactic acid, a liquid from the sugar
Use this
Flow diagram (model, not to scale), drawn in a bacterium in warm milk. A, a substance that makes the milk sour and thick. No wavy arrow is drawn.
Bacteria in warm milk ferment the milk sugar. Luz asks what the bacteria make that sours and thickens the milk.
- Carbon dioxide gas, which makes the milk rise
- Nothing, because bacteria cannot ferment; yeast do
- Lactic acid, made from the milk sugar
- Oxygen, which the bacteria need to ferment
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 uses oxygen as the final electron acceptor
- Respiration that nets about 2 ATP per glucose in total
- Respiration that makes ATP without using any oxygen
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
- Turning NADH back into NAD+ so glycolysis can continue
- Using oxygen to finish breaking down the pyruvate
- Making most of the cell's ATP after glycolysis
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?
- 0 ATP
- 2 ATP
- 4 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?
- Neither, because the two cells make the same
- Cell Q, because fermentation makes more ATP
- 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?
- 4 NADH, two for each pyruvate
- 2 NADH, one for each pyruvate
- 0 NADH, because NADH is made in the mitochondrion
- 1 NADH, one for each glucose