Proximate causes - The subject of cell biology, neurobiology, and many other biological disciplines.

Ultimate causes - Their historical causes, especially the action of natural selection.

TLS Online TPP Program

#Id: 9261

#Unit 6. System Physiology – Plant

TLS Online TPP Program

#Id: 2769

#Unit 13. Methods in Biology

DNase footprinting gives a good idea of the location of the binding site for the protein, but DNase is a macromolecule and is therefore a rather blunt instrument for probing the fine details of the binding site.

TLS Online TPP Program

#Id: 8136

#Unit 2. Cellular Organization

Golgi apparatus is a major site of carbohydrate synthesis, as well as a sorting and dispatching station for proteins products.

TLS Online TPP Program

#Id: 6497

#Unit 3. Fundamental Processes

On a linear template, ATP hydrolysis, TFIIE, and the helicase activity of TFIIH (provided by the XPB and XPD subunits) are required for polymerase movement. This requirement is bypassed with a supercoiled template. This suggests that TFIIE and TFIIH are required to melt DNA to allow polymerase movement to begin. To extend elongation into the transcription unit, a kinase complex called P-TEFb is required. P-TEFb contains the CDK9

kinase, which is a member of the kinase family that controls the cell cycle. P-TEFb acts on the CTD to phosphorylate it further on serine 2 of the heptapeptide repeat.

TLS Online TPP Program

#Id: 9372

#Unit 4. Cell Communication and Cell Signaling

Ski recruits N-CoR, which binds directly to mSin3A; mSin3A interacts with HDAC, that promotes histone deacetylation on nearby promoters, repressing gene expression