These epithelial barriers include the skin and the tissue surfaces connected to the body’s openings.

Skin and other epithelia provide a kind of living “plastic wrap” that encases and protects the inner domains of the body from infection.

TLS Online TPP Program

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#Unit 3. Fundamental Processes

There are two basic types of DNA synthesis

TLS Online TPP Program

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#Unit 2. Cellular Organization

trp operon can run even in the presence of repressor. The attenuation system permits another 10-fold control over the operon’s activity.  Thus, the combination of repression and attenuation controls the operon over a 700-fold range, from fully inactive to fully active: (70-fold [repression] X 10-fold [attenuation] = 700-fold). 

TLS Online TPP Program

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#Unit 4. Cell Communication and Cell Signaling

11-cis-retinal covalently attached to the amino group of lysine residue 296 in the opsin protein

TLS Online TPP Program

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#Unit 2. Cellular Organization

Tem1-GTP activates a protein kinase cascade, which promotes the release of active Cdc14 from the nucleolus and exit from mitosis. 

TLS Online TPP Program

#Id: 1434

#Unit 4. Cell Communication and Cell Signaling

Three major classes of animal-cell junctions: 

1. Anchoring junctions

2. Tight junctions

3. Gap junctions