ATP: the cell's energy carrier
Grade 9 Science Worksheet - Challenge Me
Circle the best answer.
Flow diagram (model, not to scale), drawn inside the cell membrane. Ari reads that one ATP's hydrolysis releases 7.3 kcal/mol and moving one sodium ion across a membrane takes 2.1 kcal/mol. How many whole sodium ions could that energy move?
- 9 ions: 7.3 + 2.1 = 9.4, and that is rounded down to 9
- 1 ion: each ATP is meant to move a single sodium ion
- 3 ions: 3 × 2.1 = 6.3 fits in 7.3, but 4 × 2.1 = 8.4 does not
- 4 ions: 7.3 ÷ 2.1 = 3.5, and half an ion is rounded up to 4
Read this first
Use this
Flow diagram (model, not to scale), drawn inside the cell. Inputs in boxes on the left: ATP; model reaction X. Outputs in boxes on the right: ADP and Pi; model reaction X done. A wavy arrow points out of the reaction: 14 kcal/mol released by ATP hydrolysis in a living cell. Each run of model reaction X needs 5 kcal/mol.
Bo reads that ATP hydrolysis in a living cell releases 14 kcal/mol. A model reaction X needs 5 kcal/mol each time. How many whole runs of X can one ATP drive?
- 3 runs: 14 ÷ 5 = 2.8, and the 0.8 is counted as a whole run
- 0 runs: ATP releases energy, so it cannot drive anything
- 9 runs: 14 − 5 = 9, and each run uses up one unit of 5
- 2 runs: 2 × 5 = 10 fits in 14, but 3 × 5 = 15 is too much
This is the first step of glycolysis. In the first step of glycolysis, a cell spends ATP to add a phosphate group to glucose. Esme asks why. What is the best reason?
- The ATP is used up for good once it gives away its phosphate
- Adding a phosphate to glucose needs energy, and ATP hydrolysis supplies it
- Adding a phosphate to glucose releases energy, so ATP is a spare
- ATP stores the glucose until the cell needs it later on
Use this
Flow diagram (model, not to scale), drawn inside the cell. Inputs in boxes on the left: glucose, amount not shown. Outputs in boxes on the right: energy extracted: 17 energy units (model data); energy released as heat: the rest. No wavy arrow label is drawn. OpenStax: glucose pathways extract about 34 percent of the energy in glucose.
Luz reads that glucose-breakdown pathways extract about 34 percent of the energy in glucose and release the rest as heat. A model cell extracts 17 energy units. About how many units did the glucose hold?
- About 6, because 34 percent of 17 is about 6
- About 50, because 17 is about 34 percent of 50
- About 17, because the cell extracts the full amount
- About 83, because 17 plus the 66 percent lost is 83
Use this
Flow diagram (model, not to scale), drawn inside the cell. Inputs in boxes on the left: line 1: ATP and water. Outputs in boxes on the right: line 2: ADP, with 2 phosphate groups, and Pi; line 3: ADP and Pi leave the cell as waste; line 4: glucose breakdown later supplies energy to rebuild. A wavy arrow points out of the reaction: line 1: energy released.
Milo's notebook describes what happens to ATP in a cell, in four lines. Which line has a flaw?
- Line 3: ADP and Pi are rebuilt into ATP, not thrown away
- Line 1: ATP should hold its energy for weeks, not release it
- Line 2: ADP should have 3 phosphate groups, like ATP
- Line 4: rebuilding ATP needs no energy, so line 4 is extra
Flow diagram (model, not to scale), drawn inside the cell. Noah's notebook shows ATP and water becoming ADP and Pi, with a wavy arrow into the reaction labeled energy needed. What is the flaw?
- The arrow is right: making ADP and Pi from ATP needs an energy input
- The wavy arrow should point out: breaking ATP down releases energy
- Water should be an output, since hydrolysis releases water
- The ADP box should show 3 phosphate groups to match ATP
ATP in a working model cell (model data)
time (s) ATP present ATP broken down each second ATP rebuilt each second 0 60 12 12 10 60 12 12 20 60 12 12 Pia says the amount of ATP stayed at 60, so the cell used none. What is the flaw in that claim?
- The amount should rise, because using ATP makes more of it
- A steady amount can mean ATP is rebuilt as fast as it is used
- A steady amount shows the ATP was stored away in the cell, not used
- The amount should fall, because used ATP is gone for good
Where cells keep energy (real data, from OpenStax Biology 2e)
form of energy how it is used ATP immediate work starch in plants stored glucose fats long-term storage Ren says a plant should keep its winter energy as ATP in every cell. Which reply is best?
- Disagree: plants keep their winter energy as ADP, which holds more than ATP
- Agree: ATP is a stable long-term store, like starch
- Disagree: ATP is for immediate work, so plants store sugar as starch
- Disagree: plants cannot store energy in any form
Use this
Flow diagram (model, not to scale), drawn inside the cell. No wavy arrow label is drawn. No wavy arrow labels are drawn.
Tala's friend says rebuilding ATP is what releases the energy a cell uses for work. Which reply is correct?
- Agree: ADP and Pi make the energy by themselves
- Agree: joining the third phosphate to ADP releases energy
- Disagree: rebuilding takes energy in; breaking ATP down releases it
- Disagree: rebuilding releases energy, and breaking takes it in
ATP made during glucose breakdown (real data, from OpenStax Biology 2e)
process share of the ATP where it happens chemiosmosis 90 percent mitochondria in a eukaryotic cell substrate-level phosphorylation a few ATP molecules steps of the glucose pathways Zee reads that the mitochondria in a model muscle cell stop working. Which prediction fits the card?
- ATP rebuilding stays the same, since ADP and Pi make energy alone
- ATP rebuilding stops at once, since the ATP is used up for good
- ATP rebuilding falls sharply, since 90 percent of the ATP from glucose is made in mitochondria
- ATP rebuilding stays the same, since stored ATP lasts for months