Body Systems
This system breaks down food into small molecules.
Digestive System
This molecule comes from food and gives cells energy.
Glucose
What organelle is known as the “powerhouse” of the cell?
Mitochandria
What happens to oxygen after it enters your lungs?
It moves into the blood and travels to the cells.
Why does a runner breathe harder during a race?
Their cells need more oxygen to make energy.
This system moves molecules like oxygen and glucose through the body.
Circulatory System
This gas comes from the air and helps make energy in cells.
Oxygen
What two molecules are needed for cellular respiration?
Glucose and Oxygen
What happens to molecules like starch and protein when they enter the body?
They get broken down into smaller molecules the body can use (like glucose and amino acids).
Why do we eat when we’re hungry?
Our cells need glucose for energy.
This system brings oxygen into the body and removes carbon dioxide.
Respiratory System
This molecule is a waste product that cells make during energy production.
Carbon Dioxide
What process happens inside the mitochondria to make energy?
Cellular Respiration
Some athletes use “blood doping” to add extra red blood cells before a race. Why might this give them an unfair advantage?
More red blood cells mean more oxygen can travel in the blood, so their cells make energy faster.
How does the body use stored fat molecules?
It turns them into energy when glucose runs low.
These three systems work together to give cells what they need for energy.
Digestive, Circulatory, Respiratory, systems
These molecules come from food like bread and potatoes and break down into glucose.
Starch
What three things are made after cellular respiration?
Water, Carbon dioxide, and energy
Why do athletes need more energy during exercise?
Their cells use glucose and oxygen faster, so their metabolism speeds up to make more energy.
What might happen to someone who can’t absorb nutrients properly?
Their cells wouldn’t get enough glucose → low energy.
What would happen if the circulatory system stopped working?
Cells wouldn’t get oxygen or glucose → no energy → body can’t function.
These two nutrients build and repair body tissues.
Protein and Amino Acids
Explain what would happen to a cell if it didn’t have mitochondria.
It couldn’t make energy, and the cell would die.
In your own words, describe the path a molecule of glucose takes from food to cell energy.
Food → Digestive system → Blood → Cell → Mitochondria → Energy made
How does eating a balanced diet with protein, carbs, and fats help your body’s metabolism stay healthy?
Each nutrient plays a role — carbs give glucose for energy, proteins repair cells, and fats store energy — together they keep metabolism running smoothly.