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Guest Lecture - Maggie Werner-Washburne

Elizabeth Montano

Monday's lecture began with opening our minds to what we see isn't always what there is, perhaps it never is. We were then asked to view photographs of how mitochondria are presented to us in text books and cellular models. The picture is of a bean like object with a repeating S like structure in the center. There are actually two bilayered membranes belonging to the mitochondrial structure. From this picture in mind we moved on to a discussion about the specialties that exist in science, the imbedded disciplines that have greatly contributed to the discovery and new knowledge of mitochondrial associated diseases. These subjects include cell biology, biochemistry, genetics, molecular biology, and genomics. The questions that guide each subdiscipline include what do I see, what genes are required for X, what happens when I do X to DNA, and what do they all do together?

The following information provided to us was about the structure of the mitochondria. The discussion began with a freeze etch image that was achieved by freezing mitochondria, pulling them apart, placing a layer of metal on top, then using electron microscopy. The membranes belonging to the mitochondria have more concentrated proteins on the inner most membrane. The etch showed proteins more spread out and larger in the outer membrane. We moved on to discuss the mechanics of the organelle, which includes the special role of respiration. Respiration involves five protein complexes, within these complexes we were asked to place attention on the number of nuclear DNA subunits (there are more) and the number of mitochondrial DNA subunits (there are less). The aforementioned subunits are known from genetics and molecular biology. Following this discussion we were introduced to the online Mendelian inheritance in man (OMIM) website of diseases. This website displayed 1,000 mitochondrial related diseases when mitochondria respiratory chain complex was searched. This is a frontier in cellular biology at the moment because mitochondrial related problems have many phenotypic expressions, and to a doctor symptoms appear as syndromes.

The last few things in the lecture included an imagination where we were 10┬Ám big and traveled into the mitochondria and discovered a world spread problem with providing students with models. The problem was that we believed the inner membrane not to be malleable, and to not enclose on itself to hold in the H+ concentration. We also discussed that the functional properties of even the same organelle are not the same, and that biological things are not typically/normally distributed. We summed things up with what is wrong with how we have been taught about delta G, and how to rethink about how cells are variable, and interesting characteristics of yeast cells.

Three Questions I Didn't ask:

  1. What could we use to teach students about mitochondria and all cellular components without using models? Imagination? What if students don't come close to picturing what they look like?
  2. How many of the mitochondrial related diseases are solely caused by the mitochondria?
  3. How far away are we from making the USB for mitochondrial DNA?

Three Ways to Move Forward in the Realm of Mitochondria: