The lac operator is 21-bp sequence with twofold symmetric and is recognized by two subunits of Lac repressor

 

TLS Online TPP Program

#Id: 9875

#Unit 4. Cell Communication and Cell Signaling

The main physical barriers—the body’s first line of defense—are the epithelial layers of the skin and of the mucosal and glandular tissue surfaces connected to the body’s openings

TLS Online TPP Program

#Id: 9876

#Unit 4. Cell Communication and Cell Signaling

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

#Id: 9877

#Unit 4. Cell Communication and Cell Signaling

Chemical barriers at these surfaces include specialized soluble substances that possess antimicrobial activity as well as acid pH.

TLS Online TPP Program

#Id: 9878

#Unit 4. Cell Communication and Cell Signaling

Antimicrobial proteins

TLS Online TPP Program

#Id: 9879

#Unit 4. Cell Communication and Cell Signaling

Antimicrobial peptide

TLS Online TPP Program

#Id: 9880

#Unit 4. Cell Communication and Cell Signaling

Antimicrobial peptides generally are cysteine-rich, cationic, and amphipathic. 

Because of their positive charge and amphipathic nature, they interact with acidic phospholipids in lipid bilayers, forming pores and disrupting the membranes of bacteria, fungi, parasites, and viruses.