P3 ATPases transports-H+ & Mg+2 

7. P4 ATPases are flippases, transports phospholipids 

PS, PC and PE.

TLS Online TPP Program

#Id: 9922

#Unit 4. Cell Communication and Cell Signaling

IFN-ϒ acts directly by inducing an antiviral state in nearby cells.

IL-2 acts indirectly by assisting the development of cytotoxic T lymphocyte(CTL) precursors into an effector population.

Both IL-2 and IFN-ϒ activate NK cells.

TLS Online TPP Program

#Id: 9923

#Unit 4. Cell Communication and Cell Signaling

TLS Online TPP Program

#Id: 9924

#Unit 4. Cell Communication and Cell Signaling

Viruses Employ Several Different Strategies to Evade Host Defense Mechanisms

Hepatitis C virus, inhibiting the action of PKR.

Herpes simplex virus TAP.

TLS Online TPP Program

#Id: 9925

#Unit 4. Cell Communication and Cell Signaling

Adenoviruses and cytomegalo virus use to reduce the surface expression of class I MHC molecules, 

Measles virus and HIV, reduce levels of class II MHC molecules on the surface, 

Vaccinia virus, secreting a protein that binds to the C4b complement component.

TLS Online TPP Program

#Id: 9926

#Unit 4. Cell Communication and Cell Signaling

Influenza virus

Influenza are surrounded by an outer envelope, a lipid bilayer derived from the plasma membrane of the infected cell.

Viral specific Protein 

Hemagglutinin (HA) 

Neuraminidase (NA)

TLS Online TPP Program

#Id: 9927

#Unit 4. Cell Communication and Cell Signaling

HA trimers are responsible for the attachment of the virus to host cells, binding to the sialic acid. 

NA is an enzyme that cleaves N-acetyl neuraminic (sialic) acid

Within the envelope, consists of eight different strands of single- stranded RNA (ssRNA) associated with protein and RNA polymerase.