The chi-squared test is done to check if there is any difference between the observed value and expected value. The formula for chi-square can be written as

TLS Online TPP Program

#Id: 10111

#Unit 4. Cell Communication and Cell Signaling

Gap junctions permit the passage of molecules as large as 1.2 nm in diameter (molecules smaller than 1200 Da).

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.