actomyosin contractility generates force through interactions of myosin motors with actin networks. The resulting load depends on network organization, attachments and resistance from the surroundings.

A repeating contractile unit of striated muscle containing organized filament systems. Its maturation contributes to force production but does not alone establish a cell's proliferative state.

An assembly of actin filaments and myosin motors. Network architecture, motor activity and attachments determine how contractile activity produces cellular or tissue deformation.

Spectrin is a flexible cytoskeletal protein that forms a meshwork beneath the cell membrane, often through assemblies of alpha and beta chains. Connections to membrane-associated components and actin help distribute mechanical stress. The red blood cell provides a striking example: its membrane skeleton supports repeated deformation through narrow vessels. Spectrin is also present in other cells, where related assemblies help organize membrane domains. ^[ref]

Specialised cytoplasmic material containing components that promote germline development when inherited by selected embryonic cells.

A cytokine involved in immune and other signalling, including studied effects on neural physiology. Its physiological effects depend on source, target, dose and timing.

The highly oxidizing ferryl/porphyrin-radical intermediate used in many P450 oxygenations; its subsequent reactions depend on the substrate and enzyme.

A sorghum P450 catalysing conversion of tyrosine toward p-hydroxyphenylacetaldoxime in dhurrin biosynthesis. It has served as a model for photosynthesis-powered heterologous P450 activity.

Cyclopropanation between reactive groups tethered within one molecular framework. The tether constrains approach geometry, can form an additional ring simultaneously, and can influence which alkene face reacts.

A concerted cycloaddition of a conjugated diene and a dienophile that makes a six-membered ring with two new sigma bonds and one retained alkene. The internal diene atoms become the residual alkene atoms.

A cyclin regulating cell-cycle CDK activity. Its spatial control is important in the fly male germline centrosome orientation checkpoint.

A sequence of electron transfer, chemical reaction, electron transfer and chemical reaction. Binding reactions can shift reduction potentials and separate reduction from product-release waves.

For a deterministic iteration $x_{i+1}=f(x_i)$ with eventual cycle length $\lambda$ and preperiod $\mu$, the Brent cycle-finding algorithm detects repetition using constant auxiliary space.

Hold a checkpoint fixed while another pointer advances through blocks of lengths $1,2,4,8,\dots$. At a block boundary, move the checkpoint to the advancing pointer and double the next block length. Compare each new state to the checkpoint. Once the checkpoint lies on the cycle and its block is long enough, the first equality occurs exactly $\lambda$ steps after the checkpoint.

To locate the entrance, restart two pointers at the initial state, advance one by $\lambda$ steps, then move both one step at a time until they agree. Before index $\mu$, the first pointer is outside the cycle; at $\mu$ both reach the same cyclic position. The procedure uses $O(\mu +\lambda )$ evaluations of $f$ and constant auxiliary space, assuming constant-cost state equality and copying. An infinite nonperiodic orbit has no finite detection guarantee.^[ref]

The binary diamond-related structure with two interpenetrating face-centred cubic sublattices displaced by a quarter of a body diagonal. Each site has four tetrahedrally arranged neighbours of the other species. Gallium phosphide is an example; this structure name is distinct from the mineral sphalerite.

A tetrahedral coordination unit connected to another through a shared vertex. In a fully corner-sharing network of four-coordinate cations and two-coordinate bridging anions, the anion/cation ratio is two.