The GTP that is bound to α-tubulin is physically trapped at the dimer interface and is never hydrolyzed.

TLS Online TPP Program

#Id: 8224

#Unit 2. Cellular Organization

Lysosomal storage diseases:

• Hurler’s disease

• Inclusion-cell disease

TLS Online TPP Program

#Id: 8225

#Unit 2. Cellular Organization

Hurler’s disease- mutation in a structural gene that codes for an individual lysosomal hydrolase.

TLS Online TPP Program

#Id: 8226

#Unit 2. Cellular Organization

I-cell disease

• almost all of the hydrolytic enzymes are missing from the lysosomes of many cell types.

• mis-sorting has been traced to a defective or missing GlcNAc phosphotransferase.

TLS Online TPP Program

#Id: 8311

#Unit 2. Cellular Organization

Actin,

basic building block of microfilaments extraordinarily well conserved among eukaryotes.

TLS Online TPP Program

#Id: 8312

#Unit 2. Cellular Organization

Actin exists as: 

a globular monomer -G-actin 

a filamentous polymer- F-actin

TLS Online TPP Program

#Id: 8313

#Unit 2. Cellular Organization

3 isoforms of actin-

α - expressed only in muscle cells

β and γ - found together in almost all non-muscle cells