Cellular Respiration Study Guide | High
School Biology | ATP, Glycolysis & Energy
Production
1. What is Cellular Respiration?
Cellular respiration is the process cells use to break down glucose (sugar) to produce
energy. The energy produced is stored in a molecule called ATP, which cells use to perform
many functions such as movement, growth, and repair.
Cellular respiration mainly occurs in the mitochondria, often called the powerhouse of the
cell.
2. Cellular Respiration Equation
Glucose + Oxygen → Carbon Dioxide + Water + Energy (ATP)
C₆H₁₂O₆ + O₂ → CO₂ + H₂O + ATP
This means cells take in glucose and oxygen and convert them into energy, carbon dioxide,
and water.
3. Where Cellular Respiration Happens
Different stages of cellular respiration occur in different parts of the cell.
Cytoplasm
● Location of glycolysis
Mitochondria
, ● Location of the Krebs Cycle and Electron Transport Chain
4. The Three Stages of Cellular
Respiration
Stage 1: Glycolysis
Glycolysis occurs in the cytoplasm of the cell.
What happens:
● Glucose is broken down into smaller molecules
● A small amount of ATP is produced
● Pyruvate molecules are created
Key point:
This stage does not require oxygen.
Stage 2: Krebs Cycle (Citric Acid Cycle)
The Krebs Cycle occurs inside the mitochondria.
What happens:
● Pyruvate is further broken down
● Carbon dioxide is released
● Energy-carrying molecules are produced
Key result:
Energy molecules that will be used in the next stage are created.
Stage 3: Electron Transport Chain
This stage also occurs in the mitochondria.
School Biology | ATP, Glycolysis & Energy
Production
1. What is Cellular Respiration?
Cellular respiration is the process cells use to break down glucose (sugar) to produce
energy. The energy produced is stored in a molecule called ATP, which cells use to perform
many functions such as movement, growth, and repair.
Cellular respiration mainly occurs in the mitochondria, often called the powerhouse of the
cell.
2. Cellular Respiration Equation
Glucose + Oxygen → Carbon Dioxide + Water + Energy (ATP)
C₆H₁₂O₆ + O₂ → CO₂ + H₂O + ATP
This means cells take in glucose and oxygen and convert them into energy, carbon dioxide,
and water.
3. Where Cellular Respiration Happens
Different stages of cellular respiration occur in different parts of the cell.
Cytoplasm
● Location of glycolysis
Mitochondria
, ● Location of the Krebs Cycle and Electron Transport Chain
4. The Three Stages of Cellular
Respiration
Stage 1: Glycolysis
Glycolysis occurs in the cytoplasm of the cell.
What happens:
● Glucose is broken down into smaller molecules
● A small amount of ATP is produced
● Pyruvate molecules are created
Key point:
This stage does not require oxygen.
Stage 2: Krebs Cycle (Citric Acid Cycle)
The Krebs Cycle occurs inside the mitochondria.
What happens:
● Pyruvate is further broken down
● Carbon dioxide is released
● Energy-carrying molecules are produced
Key result:
Energy molecules that will be used in the next stage are created.
Stage 3: Electron Transport Chain
This stage also occurs in the mitochondria.
