Food Molecules
What small molecule do cells use directly for energy release?
Glucose
What molecule from the air do cells need for energy release?
Oxygen
What does the digestive system do to food molecules?
Breaks them down into small molecules.
What system brings oxygen into the body?
Reparatory System
What two molecules react inside cells to release energy?
Glucose & Oxygen
Starch must be broken down into what molecule before cells can use it?
Glucose
If someone breathes very little oxygen, how will they feel during exercise?
Tired / low energy.
If the digestive system isn’t working well, what important molecule might be low in cells?
Glucose
Oxygen moves from the lungs into what system next?
Circulatory system (bloodstream).
When do cells use released energy?
Movement, running, playing sports, powering cell functions.
Can amino acids release energy for cells? Why or why not?
No—amino acids build proteins; they don’t release energy.
Why would a scuba diver with broken breathing gear struggle to swim?
Cells can’t release energy without oxygen.
In the small intestine, if “glucose: low,” what does that mean for energy?
Not enough glucose reaches the cells → low energy.
If the lungs show low oxygen molecules, what will happen to energy?
Cells cannot release enough energy.
What waste gas is created during energy release?
Carbon dioxide
A patient has low glucose in her cells but normal amino acids. Can she exercise normally?
No—she must have glucose for energy release.
A patient has normal glucose levels but low oxygen levels. What does this mean for exercise?
They cannot exercise normally because energy cannot be released.
Why can’t starch molecules go directly into cells?
They are too large; must be broken into glucose.
A patient has normal digestion but cannot get much oxygen into her lungs. What problem will she have?
She will not be able to exercise normally; low energy.
If a patient’s cells contain glucose but low oxygen, why is she tired?
Reaction cannot happen → little/no energy released.
A patient ate plenty of starch but her cells still have low glucose. What system is failing?
Digestive system
A patient has high glucose but low oxygen in cells. Can energy be released? Why?
No, oxygen is require to release energy.
Cells show low glucose even though the patient ate a full meal. What step failed?
Food wasn’t broken into glucose.
A patient’s lungs show oxygen: low but digestion is normal. Why is she tired?
Cells can’t get the oxygen required for energy.
Explain why eating protein alone (no starch) before a long run is not enough.
Protein breaks into amino acids, not glucose; cells need glucose + oxygen to release energy.