The more metabolically active cells that are present in the culture, the more formazan will be generated, and so this assay provides a readout of the number of live cells as a function of time.

TLS Online TPP Program

#Id: 10112

#Unit 4. Cell Communication and Cell Signaling

Ions, low-MW precursors of cellular macromolecules, products of intermediary metabolism, & small intracellular signaling molecules can pass from cell to cell through gap junctions.

TLS Online TPP Program

#Id: 10113

#Unit 4. Cell Communication and Cell Signaling

TLS Online TPP Program

#Id: 1356

#Unit 4. Cell Communication and Cell Signaling

The cytokines form a family of small, secreted signaling molecules (about 160–200 amino acids) that control growth and differentiation of cells.

TLS Online TPP Program

#Id: 1357

#Unit 4. Cell Communication and Cell Signaling

Family of Cytokines

• Interleukins

• Interferons

• Growth hormone

• Prolactin

• Granulocyte colony–stimulating factor

• Thrombopoietin

• Erythropoietin (Epo)

TLS Online TPP Program

#Id: 1358

#Unit 4. Cell Communication and Cell Signaling

GH, prolactin, G-CSF, thrombopoietin, and Epo evolved from a common ancestral protein.

TLS Online TPP Program

#Id: 1359

#Unit 4. Cell Communication and Cell Signaling

All cytokines have a similar tertiary structure consisting of four long conserved α helices folded together.