Lecture 2- Cytosol and Cytoskeleton Flashcards
What are the monomers for A) Microtubules
B) Intermediate Filaments C) Microfilaments?
A) Tubulin B) Several Polypeptides C) Actin
What are the sizes of the 3 Cytoskeleton Filaments (From Smallest to Largest)?
Microfilaments (7nm), Intermediate Filaments (10-12nm), Microtubules (25nm)
What filament enables the contraction/elongation of Microvilli?
Actin (Contractile; Sliding Filament Theory in Muscle Contraction)
What is the structure of Microfilaments?
Solid rods composed of 2 Actin chains. Each Actin chain comprised of G-Actin subunits that assemble into F-Actin
What is the structure of Microtubules?
Created from 2 different Globular Tubulin Proteins. 13 Tubulin molecules form a hollow tube
What is the function of the MTOC?
- Microtubule Organizing Centre (MTOC) is located at the Centrosome.
- Centrosome located centrally near Nucleus, composed of 2 Centrioles and responsible for building/degradation of Microtubules.
Which way do the Motor Proteins Kinesin and Dynein transport molecules along the Microtubules?
Kinesins away from Centre (+ end)
Dyneins towards Centre (- end)
What are the three Anti-Mitotic Alkaloids?
1) Colchine 2) Taxol 3) Vinoblastine
Each one aims to stop Microtubule Processes
(Ex. Colchine blocks Microtubule Polymerization)
What is the structure of Cilia?
Composed of 2 Microtubule Central Core surrounded by 9 Microtubule Peripheral Doublets
What Motor Protein is responsible for Cilia movement?
Dyneins catalyze the bending of Microtubules within the Cilia via conversion of ATP–> ADP
What is Cilial Dyskinesia?
- Autosomal Recessive Genetic defect affecting Cilia Motor Proteins (i.e. Dyneins).
Can lead to… a) Ectopic Pregnancy b) Male Infertility
c) Respiratory Problems
What is the major benefit of Intermediate Filaments?
Great Tensile Strength
What is Epidermolysis Bullosa Simplex?
- Genetic defect in gene for Cytokeratins 5 & 15
- Lack of Cohesion between Epithelium and Basement Membrane causing severe blisters and fluid loss
