Cryptic mutants” of lac operon make b-galactosidase but still could not grow on lactose means they are essentially Y-

TLS Online TPP Program

#Id: 1396

#Unit 4. Cell Communication and Cell Signaling

All small GTPases of the Ras superfamily, Cdc42, Rac, and Rho act as molecular switches, inactive in the GDP-bound state and active in the GTP-bound state.

TLS Online TPP Program

#Id: 1397

#Unit 4. Cell Communication and Cell Signaling

Actin-based motors powered by ATP hydrolysis.

TLS Online TPP Program

#Id: 1398

#Unit 4. Cell Communication and Cell Signaling

Myosins have 

  Motor head domain

  Lever-arm neck domain

  Cargo-binding tail domain

TLS Online TPP Program

#Id: 1399

#Unit 4. Cell Communication and Cell Signaling

The first myosin discovered

Myosin II, was isolated from skeletal muscle.

TLS Online TPP Program

#Id: 1400

#Unit 4. Cell Communication and Cell Signaling

Three classes of myosins:

Myosin I

Myosin II

Myosin V

TLS Online TPP Program

#Id: 1401

#Unit 4. Cell Communication and Cell Signaling

Myosin I

single head domain

Function- Membrane association, endocytosis