Tight junctions prevent the diffusion of: 

Macromolecules

Small water-soluble molecules

Ions

Membrane proteins 

Glycolipids

TLS Online TPP Program

#Id: 3328

#Unit 3. Fundamental Processes

The significance of transcription-coupled repair is that it focuses repair enzymes on DNA (genes) being actively transcribed.

TLS Online TPP Program

#Id: 991

#Unit 5. Developmental Biology

An anterior-to-posterior gradient of Bicoid protein.

TLS Online TPP Program

#Id: 9078

#Unit 4. Cell Communication and Cell Signaling

GRK–β-arrestin pathway, suppress signaling by GPCRs, actually functions as a switch, turning off signaling by G proteins and turning on other signaling pathways.

TLS Online TPP Program

#Id: 5508

#Unit 10. Ecological Principles

                                                                                                                                               

TLS Online TPP Program

#Id: 3011

#Unit 3. Fundamental Processes

The E. coli SSB is a tetramer; eukaryotic SSB (also known as RPA) is a trimer.