Lecture 9: Cytoskeleton and Cell Motility

Chapter 4

	Topic	Reading
	Protein Structure Quaternary Structure Subunit Interaction Concept: Many functional macrostructures exist as assemblies of individual protein chains each with its own tertiary structure but dependent on the interaction with other proteins to make a functional structure. examples: Hemoglobin Ribosomes microfilaments microtubules	page 69-72
	Cytoskeleton Dynamic Network for cellular movement and organization Concept: The structure of the cell is dynamic resulting from the ability of the structures of the cytoskeleton to reversibly assemble and disassemble under the control of changes in the cellular environment. The cytoskeleton is an example of quaternary structures bound together by hydrogen bonding, hydrophobic interactions and ionic bonding. microtubules (hollow tubes) (25 nm diameter) alpha and beta tubulin dimerization polarity microtubule-organizing center centrioles (9X3) structure microfilaments (actin filaments) (7 nm diameter) two actin filaments wound together mechanical support with myosin for motion Intermediate filaments irreversible assembly stabilize cell shape	pages 104 - 109
	Motility Concept: Many biological functions can be performed by common structures using assemblies of molecules in unique combinations Kinesin Movement of organelles along microtubules requires energy Cilia (many, short) and Flagella (few, long) movement of cells tubulin assemblies (9X2) basal body (9X3)	page 106 - 107

Review:

Chapter 4: Post-Test question 9 - 11

You make the Connection: question 1

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