AP Bio Chapter 6-7 Part 1 Flashcards
Structure of cytoskeleton
A network of structural proteins that extends throughout the cytoplasm
The cytoskeleton
A dynamic regulator of cellular structure and support
What are some examples of the cytoskeleton
Microtubules, microfilaments, intermediate filaments
What’s the structure of microtubules (tubulin polymers)
Hollow tubes, wall consists of 13 columns of tubulin molecules
Lumen
In the middle of something
Functions of microtubules
Maintenance of cell shape (compression resisting girders)
Cell motility
Chromosome movements in cell division
Organelle movements
What’s the structure of microfilaments (actin filaments)
Two intertwined strands of actin,each a polymer of actin subunits.
What are the functions of microfilaments
Maintenance of cell shape (tension bearing elements)
Changes in cell shape
Muscle contraction
Cytoplasmic streaming
Cell motility (as in pseudopodia)
Cell division (cleavage furrow furrow formation)
What is the structure of intermediate filaments
Fibrous proteins supercoiled into thicker cables
Function of intermediate filaments
Maintenance of cell shape (tension bearing elements)
Anchorage of nucleus and certain other organelles
Formation of nuclear lamina
What are the functions of the cytoskeleton
Structural support
Maintaining cell shape
Anchorage of organelles
Regulation of cell and organelle mobility
Movement of chromosomes during cell divisions
Centrioles produces microtubules, only animal cells in the centrosome
Function when flagellum and microfibers are used
Structure of centrosome
A microtubule organizing center in animal like cells
Function of centrosome
Origin of all microtubules in cell, major role in cell division
Structure of the cell membrane
The fluid mosaic model, a phospholipid bi layer with associated proteins
Function of the cell membrane
Boundary of the cell
Transport of materials in/out of the cell
Communications between cell/environment
What are peripheral proteins
Outside membrane
Integral proteins
Inside membrane, some are transmembrane channels, pumps receptors
What are the regroups inside the membrane
Hydrophobic
What are the r groups outside the membrane
Hydrophilic
What in proteins can identify cell to cell
Carbohydrates stuck to them
What is the structure of membrane phospholipids
Lipids with a phosphate attached to glycerol in place of a fatty acid tail
Polar phosphate head (hydrophilic) nonpolar fatty acid tail (hydrophobic) called amphipathic
What do membrane phospholipids do in the presence of water
Spontaneously organizes to form a bilayer
How are the membrane phospholipids fluid
They are constantly moving
What are the functions of membrane phospholipids
Make a selectively permeable membrane, only small nonpolar molecules can easily move throughout the phospholipid bilayer
