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?
- Branch B, because fermentation needs oxygen to run
- Both branches, because pyruvate has to use each one
- Neither branch, because a cell with no oxygen makes no ATP
- Branch A, because fermentation does not need oxygen
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.
- Fermentation, in the cytoplasm
- Fermentation, in the mitochondrion
- Glycolysis, in the cytoplasm
- Glycolysis, in the mitochondrion
Jun reads a reaction in a muscle cell low on oxygen: pyruvate + NADH → A + NAD+. What goes in box A?
- Lactate, also called lactic acid
- ATP, made by the fermentation step
- NADH, made again from the NAD+
- Carbon dioxide, released as a gas
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
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.
- Oxygen, which the bacteria need to ferment
- Nothing, because bacteria cannot ferment; yeast do
- Lactic acid, made from the milk sugar
- Carbon dioxide gas, which makes the milk rise
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?
- Respiration that nets about 2 ATP per glucose in total
- Respiration that makes ATP without using any oxygen
- A way to turn NADH back into NAD+ with pyruvate
- Respiration that uses oxygen as the final electron acceptor
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 that cannot make any ATP
- A process found in yeast cells alone
- A process that runs without oxygen
- A process that needs oxygen to get started
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?
- about 30 ATP
- 4 ATP
- 2 ATP
- 0 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 P, with about 30 ATP
- Neither, because the two cells make the same
- Cell Q, because fermentation makes more 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
- 4 NADH, two for each pyruvate
- 1 NADH, one for each glucose
