Lecture 33 – Mitochondria and the Krebs Cycle November 18, 2013
• Outer membrane
• Inner membrane that fold inward in ridges called cristae
• There is the inter-membrane space between the inner and outer membranes
• The inside lumen of the cell contains the matrix.
• There are proteins in the outer membrane, particularly transport channels like Porin, a passive
channel that allows liquids to pass through the membrane.
• The inter-membrane space is not particularly specialized.
• There are many small particles (originally called elementary particles, discovered by Roberto
Fernandez Peru) that cover the surface of the Cristae.
• These particles are now called F F1 0Pase.
• Contains many soluble enzymes, ribosomes, mitochondrial DNA, and Ca . 2+
Assembly of Mitochondria
• Some proteins are synthesized by mitochondria itself using mRNAderived from mitochondrial
• Many proteins however, are constructed using DNAfrom the cell nucleus, these cells are made
in the cytoplasm.
• Proteins made in the cytoplasm are tagged and brought by carrier proteins to the mitochondria.
• For membrane proteins, there is likely repeating hydrophobic sections and hydrophilic sections
that , when arranged in a helix, form a protein that has a hydrophobic side and a hydrophilic
side, allowing a side of the protein to dissolve in the membrane.
• HSP and GroE1 are a chaperone (heat-shock) proteins within the mitochondria.
• Pyruvate is produced via glycolysis, it is transported to the mitochondria and there pyruvate is
converted toAcetyl CoenzymeA and NAD(H).
• Was trying to figure out how sugars were processed in the cell. • By crushing tissue (and thus mitochondria) and using paper chromatography, he found many
sugars of different types.
• He found:
◦ Malate – from apples
◦ Citrate – from lemons, etc.
◦ Fumarate – named because its distillation process produced a lot of smoke.
◦ Aconitic – found in aconites (a family of plants related to buttercups, many are poisonous).
He used the Warburg Apparatus
• Put a piece of tissue in an Erlenmyer
• Connect the flask to a manometer tube containing red liquid, feed the tissue a sugar while