Question

1. raoul ate a meal of oats before seeing his doctor. oats are made of mostly starch molecules. raoul feels tired, so his doctor gave him a test and found that raoul’s cells contained glucose molecules, but they did not contain enough oxygen molecules. does this explain why raoul feels tired?

no, something else must be wrong because his cells have all the molecules they need.
yes, his digestive system is breaking down starch molecules, but his respiratory system may not be working properly.
yes, his respiratory system is working, but his digestive system is not getting energy from combining glucose molecules.
yes, his digestive system is working, but his respiratory system is not breaking down oxygen, so his body stopped making energy.

1. some problems with the digestive system make it very difficult for the body to digest enough food. why would it be harder to exercise when you have a digestion problem like this?

you would not be able to sleep, which would make you too tired to exercise.
your cells would have molecules from air, but would not get enough molecules from food.
you would need to breathe in a lot more air because your body would have fewer molecules from food.
you would not get any of the molecules your cells need to exercise.

Explanation:

Question 10

To determine the answer, we analyze cellular respiration: cells need glucose (from digestion of starch) and oxygen (from respiration) to produce energy. Raoul has glucose (so digestive system works to break down starch to glucose) but not enough oxygen (so respiratory system may not supply enough). Let's evaluate options:

• First option: Wrong, as cells lack oxygen, so they don't have all needed molecules.
• Second option: Correct. Digestive system breaks down starch to glucose (so glucose is present), but respiratory system may not provide enough oxygen for energy production, causing tiredness.
• Third option: Wrong, digestive system breaks down, not combine, glucose; energy is from cellular respiration (glucose + oxygen), not digestive system combining glucose.
• Fourth option: Wrong, respiratory system doesn't break down oxygen; it supplies oxygen for glucose breakdown in cells.

Digestion problems mean less food is digested, so cells get fewer food - derived molecules (like glucose) needed for energy. Let's analyze options:

• First option: Sleep isn't directly related to digestion - exercise difficulty here.
• Second option: Correct. Cells get oxygen (from air, respiratory system) but not enough food - derived molecules (from digestion) for energy, making exercise hard.
• Third option: Breathing more air won't compensate for lack of food - derived energy - source molecules.
• Fourth option: Wrong, cells still get some food molecules (just not enough), not none.

Answer:

Yes, his digestive system is breaking down starch molecules, but his respiratory system may not be working properly.

Question 11