Fig 014 Mitochondria

Mitochondria

Mitochondria are double-membrane bound organelles that supply energy to the cell through oxidative metabolism. Depending on cell type, their number and size is highly variable.

• Outer Membrane - separates the contents of mitochondria from the cytoplasm
• Inner Membrane - narrow space between it and the outer membrane
  • Cristea - infoldings of the inner membrane that increases its surface area
    • Extend at right angles to the mitochondrial axis but do not reach the opposite side
  • ATP Synthase - particles that cover the inner surface of the inner membrane
• Matrix - often seen to contain ribosome-like particles and granules

Cells that produce large amounts of steroid often contain mitochondria with tubules instead of cristae.