Transcript Mitochondria

Chapter 4.7
Mitochondria
AP Biology
Fall 2010
Objectives
• Describe the structure and function of the
mitochondria
• Understand the origins of the mitochondria
Mitochondria
• Mitochondria: primary organelles for
transferring the energy in carbohydrates to
ATP under oxygen-plentiful conditions
• Reactions in this organelle help cells extract
more energy from organic compounds than
they can get by any other means
Mitochondria
• Structure:
– Each mitochondria has two membranes, an inner folded
membrane (cristae) surrounded by a smooth outer
membrane
– Inner and out membranes important in energy
transformations
Mitochondria
• Aerobic respiration occurs in mitochondria
– Requires free oxygen
– A.R = the production of ATP from glucose
Mitochondria
• Membrane arrangement creates two
compartments
• Hydrogen ions become stockpiled in outer
compartment, ions then flow to inner
compartment in controlled way
• Energy inherent in the flow drives ATP
production
Mitochondria
• No prokaryotes have mitochondria
• Nearly all eukaryotes do
• Different cells contain different amounts of
mitochondria depending on their needs
Mitochondria
• Resemble bacteria in size and biochemistry
• Like bacteria, have their own DNA and divide
on their own apart from the cell
• Have ribosomes
MItochondria
• Endosymbiosis: theory that explains how
mitochondria may have once been
independent ancient prokaryotic cells
– Became engulfed by another cell but became
permanent
– Remaining with host cell as an endosymbiont
Mitochondria
Review
1. What are the main structural components of
the mitochondria?
2. What is the main process that occurs in the
mitochondria?
3. In what ways does the mitochondria’s
structure help it’s function?
Answers
1. The main structural components include the
outer membrane and the inner membrane
called the cristae. The inner compartment
makes up the mitochondrial matrix.
2. The main process that occurs in the
mitochondria is ATP synthesis.
3. The many inner membrane folds give a larger
surface area for ATP synthesis and the
electron transfer chain.