For males, spermatogenesis is energetically cheap, less than 1% of basal metabolic rate (Elia 1992), and male fecundity is relatively insensitive to energetic constraint (Bribiescas 2001a).
To do so, we formulate the inverse problem in terms of energetically distinct configurations, using a constraint satisfaction model to identify constructible configurations, and show that a convex hull can be used to identify ground states.
Of note, although biophysical analyses of RNA duplexes indicate that UU base-pairing is more stable than UC pairs at pH 7.0, the observation that the AGC codon promoted>2-fold more misreading than the AGU codon suggests that this particular UC base pair is more energetically permissible within the topological constraints imposed by the codon:anticodon mini-helix structure.
Note that although there are three possible UU base pairs and two possible CU couples, the geometries of the N3-N3, 4-carbonyl-amino, and of the 2-carbonyl-N3, 4-carbonyl-N3 hydrogen pairing schemes provide the most energetically favorable topologies within the constraints of the tRNA:mRNA mini-helix.
The cost of maintaining and supporting energetically demanding neurons is the key constraint on brain size.
The paradigm used here over-predicts the probability of proline, since other amino acids are energetically unfavorable due to the steric constraints of the backbone.
The knowledge of experimental structure even at a relatively low crystallographic resolution around 3 Å provides firm constraints for search of energetically favorable replacements and removes unavoidable uncertainty of computer-predicted structural models.
Hydrodechlorination is shown to be an electrophilic reaction where, in the absence of appreciable steric constraints, chlorine removal is more energetically demanding from DCP than CP.
The conformation of this strand-loop-helix motif causes the nucleophilic residue to adopt energetically unfavorable backbone dihedral angles that impose steric constraints on vicinal residues [ 37, 39, 42].
We found that the most energetically favorable orientation is actually the orientation determined by structural constraints (Fig. 2(B)).
