Question

1. jamal ate a meal of rice before seeing his doctor. rice is made of mostly starch molecules. jamal has been feeling tired a lot, so his doctor gave him a test that found that jamals cells contained normal levels of oxygen and low levels of glucose. does this explain why jamal has been feeling tired?

a yes, jamals respiratory system is working, but his digestive system is not turning the oxygen into glucose.
b yes, jamals respiratory system is working, but his digestive system is not breaking down starch molecules into glucose for his cells.
c yes, jamals digestive system is working, but his respiratory system has too much oxygen, so his body stopped making energy.
d no, something else must be wrong with jamal because his cells have all the molecules they need.

Explanation:

• The body needs glucose for cellular respiration to produce energy. Rice has starch. The digestive system should break down starch into glucose.
• If the digestive system fails to break down starch (as in option b), cells lack glucose. Even with oxygen (respiratory system working), without glucose, energy production (cellular respiration: \(C_6H_{12}O_6+6O_2

ightarrow6CO_2 + 6H_2O+\text{energy}\)) is impaired, leading to tiredness.

• Option a is wrong because oxygen is not turned into glucose. Option c is wrong as too much oxygen doesn't stop energy - making. Option d is wrong as cells lack glucose.

Answer:

B. Yes, Jamal’s respiratory system is working, but his digestive system is not breaking down starch molecules into glucose for his cells.