The Cytoskeleton Flashcards
What are the three filament types of the cytoskeleton?
- Microtubules
- Microfilaments
- Intermediate filaments.
What are the functions, components, and diameter of microtubules?
- Movement and support.
- Made up of the protein tubulin.
- The diameter is about 25nm.
What are the functions, components, and diameter of microfilaments?
- Movement and support.
- Made up of the protein Actin
- The diameter is about 6nm.
What are the functions, components, and diameter of intermediate filaments?
- Support.
- Made up of various proteins.
- The diameter is about 10nm.
What are the two ends of the microtubules called?
The plus end and the minus end.
Which end of the microtubules grows the fastest?
The plus end.
What end of the microtubules are anchored close to the centrioles?
The minus end.
In what cellular structures can you find microtubules?
In cilia and in centrioles.
Microtubules fuse side by side to form doublets or triplets
What microtubule structures do cilia contain?
9 peripheral doublets (18 microtubules fused together in pairs)
2 central microtubules.
What microtubule structures do a centriole contain?
9 peripheral triplets.
What is a centrosome?
A centrosome is a pair of centrioles.
In which cases are microfilaments stable?
In cell-cell junction, microvilli, terminal web in epithelial cells, thin myofilaments in muscle cells.
What is the function of the motor enzymes (motor proteins)?
Motor enzymes walk along the cytoskeletal filaments transporting vesicles of compounds. They are together with the microtubules responsible for the intracellular movement of vesicles, organelles, and chromosomes.
What motor enzyme walks toward the + end of the microtubules?
Kinesin
What motor enzyme walks toward the - end of the microtubules?
Dynein