Cell Structure 3 (1)

Cell Structure 3 (1) - Components of the Cytoskeleton Three...

Info iconThis preview shows pages 1–12. Sign up to view the full content.

View Full Document Right Arrow Icon

Info iconThis preview has intentionally blurred sections. Sign up to view the full version.

View Full DocumentRight Arrow Icon

Info iconThis preview has intentionally blurred sections. Sign up to view the full version.

View Full DocumentRight Arrow Icon

Info iconThis preview has intentionally blurred sections. Sign up to view the full version.

View Full DocumentRight Arrow Icon

Info iconThis preview has intentionally blurred sections. Sign up to view the full version.

View Full DocumentRight Arrow Icon

Info iconThis preview has intentionally blurred sections. Sign up to view the full version.

View Full DocumentRight Arrow Icon

Info iconThis preview has intentionally blurred sections. Sign up to view the full version.

View Full DocumentRight Arrow Icon
This is the end of the preview. Sign up to access the rest of the document.

Unformatted text preview: Components of the Cytoskeleton Three main types of fibers make up the cytoskeleton Microtubules are the thickest of the three components of the cytoskeleton Microfilaments , also called actin filaments, are the thinnest components Intermediate filaments are fibers with diameters in a middle range Tubulin dimer 25 nm Column of tubulin dimers 10 m 10 m Actin subunit 7 nm 5 m Keratin proteins Fibrous subunit (keratins coiled together) 8- 12 nm Microtubules Microtubules are hollow rods about 25 nm in diameter and about 200 nm to 25 microns long Functions of microtubules Shaping the cell Guiding movement of organelles Separating chromosomes during cell division Centrosomes and Centrioles In many cells, microtubules grow out from a centrosome near the nucleus The centrosome is a microtubule-organizing center In animal cells, the centrosome has a pair of centrioles , each with nine triplets of microtubules arranged in a ring Centrosome Longitudinal section of one centriole Centrioles Microtubule 0.25 m Microtubules Cross section of the other centriole Cilia and Flagella Microtubules control the beating of cilia and flagella , locomotor appendages of some cells Cilia and flagella differ in their beating patterns Direction of swimming (b) Motion of cilia Direction of organisms movement Power stroke Recovery stroke (a) Motion of flagella 5 m 15 m Cilia and flagella share a common structure A core of microtubules sheathed by the plasma membrane A basal body that anchors the cilium or flagellum A motor protein called dynein , which drives the bending movements of a cilium or flagellum Microtubules Plasma membrane Basal body Longitudinal section of motile cilium (a) 0.5 m 0.1 m 0.1 m (b) Cross section of motile cilium Outer microtubule doublet Dynein proteins Central microtubule Radial spoke Cross-linking proteins between outer doublets Plasma membrane Triplet (c) Cross section of basal body...
View Full Document

Page1 / 36

Cell Structure 3 (1) - Components of the Cytoskeleton Three...

This preview shows document pages 1 - 12. Sign up to view the full document.

View Full Document Right Arrow Icon
Ask a homework question - tutors are online