Mitochondria

What are mitochondria?

• Membrane-bound organelles

• Produce energy (ATP)

• Perform aerobic cellular respiration.

Why are mitochondria called the “powerhouse of the cell”?

• Generate most of the cell’s ATP

• Provide energy for cellular processes.

Where are mitochondria found?

• Eukaryotic cells

  • Both animal and plant cells.

What is ATP?

• Main energy molecule for cells

• Powers movement, transport, synthesis.

Do all cells have the same number of mitochondria?

• No

• High-energy cells (e.g., muscle, liver) have more

• Low-energy cells have fewer.

What is the structure of a mitochondrion?

Outer membrane: Smooth, protective barrier
Inner membrane: Folded into cristae, holds ETC
Cristae: Increases SA for ATP production
Matrix: Fluid-filled center with enzymes for the Krebs cycle.

What are cristae, and why are they important?

Folds of the inner membrane
Increase surface area
Allow more ATP-producing enzymes to function.

What are the main functions of mitochondria?

Produce ATP via aerobic respiration
Regulate cellular metabolism
Trigger apoptosis (programmed cell death)

What is the chemical equation for cellular respiration?

C₆H₁₂O₆ + 6O₂ → 6CO₂ + 6H₂O + ~36 ATP
Glucose + Oxygen → Carbon dioxide + Water + Energy (ATP).

What are the three main stages of cellular respiration in mitochondria?

Glycolysis (in cytoplasm)
Krebs cycle / Citric Acid Cycle (in mitochondrial matrix)
Electron Transport Chain (ETC) (on inner mitochondrial membrane).

Which part of cellular respiration produces the most ATP?

Electron Transport Chain (ETC)
Located in the inner membrane
Produces most of the ~36 ATP.

Why do mitochondria have their own DNA and ribosomes?

Evidence of bacterial origin (endosymbiotic theory)
Can make some of their own proteins.

Can mitochondria divide and reproduce?

Yes:
Divide independently of the cell
Use a process similar to bacterial binary fission.

How does mitochondrial dysfunction affect the body?

Causes energy deficiency
Symptoms: fatigue, muscle weakness, neurological issues
May lead to mitochondrial diseases.