Instruct: Identify the main and secondary category of Arxiv papers based on the titles and abstracts
Query: Tensile Forces and Shape Entropy Explain Observed Crista Structure in
  Mitochondria   A model is presented from which the observed morphology of the inner
mitochondrial membrane can be inferred as minimizing the system's free energy.
Besides the usual energetic terms for bending, surface area, and pressure
difference, our free energy includes terms for tension that we believe to be
exerted by proteins and for an entropic contribution due to many dimensions
worth of shapes available at a given energy.
  In order to test the model, we measured the structural features of
mitochondria in HeLa cells and mouse embryonic fibroblasts using 3D electron
tomography. Such tomograms reveal that the inner membrane self-assembles into a
complex structure that contains both tubular and flat lamellar crista
components. This structure, which contains one matrix compartment, is believed
to be essential to the proper functioning of mitochondria as the powerhouse of
the cell. We find that tensile forces of the order of 10 pN are required to
stabilize a stress-induced coexistence of tubular and flat lamellar cristae
phases. The model also predicts \Deltap = -0.036 \pm 0.004 atm and \sigma=0.09
\pm 0.04 pN/nm.

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The categories of this paper are: astro-ph
23
The categories of this paper are: solv-int
20
The categories of this paper are: acc-phys
9
The categories of this paper are: nlin
30
The categories of this paper are: q-alg
5
The categories of this paper are: gr-qc
27
The categories of this paper are: comp-gas
22
The categories of this paper are: chao-dyn
26
The categories of this paper are: bayes-an
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The categories of this paper are: alg-geom
31
The categories of this paper are: ao-sci
36
The categories of this paper are: cmp-lg
29
The categories of this paper are: funct-an
12
The categories of this paper are: nucl-th
34
The categories of this paper are: chem-ph
33
The categories of this paper are: plasm-ph