Regulation of Animal Cell Shape Flashcards
What is the cytoskeleton
a microscopic network of protein filaments and tubules in the cytoplasm
What are the functions and KEY FEATURES of the cytoskeleton? (4)
- helps maintain cell shape
- helps maintain position of organelles within cell
- rapidly disassembles and reassembles
- highly dynamic but provides stability
What are the 3 main components of the cytoskeleton?
- microtubules
- microfilaments
- intermediate filaments
What are the key features and functions of microtubules? (6)
- composed of tubulin subunits
- may radiate out from an organizing center (centrosome)
- resist compression
- maintain cell shape
- provide cell motility
- involved with organelle motility
What are the two ways microtubules can provide cell motility?
- flagella ( snake-like motion)
- cilia ( rowing like motion)
How do microtubules aid organelle motility within cell?
- ATP powered motor proteins can “walk” organelles along microtubules
- they allow vesicles, or other organelles, to be transported to specific targets within cell
What are microfilaments?
Double chain of actin subunits
What are the functions and key features of microfilaments? (4)
- form both linear strands and 3 dimensional networks
- resist tension
- cortical network under cell membrane make region less fluid and thus maintains cell shape
- interactions with motor proteins (myosin) support cell movement such as: muscle contraction, amoeboid movement, cytoplasmic streaming in plants
what are the key features of Intermediate Filaments? (5)
- made of various proteins such as: keratins in hair, lamins in nucleus, neurofilaments in neurons
- supercoiled into cables
- least dynamic of the cytoskeletal components
- form relatively permanent cellular structures
- may remain after cell death
What are the functions of intermediate filaments? (2)
- maintain cell shape
- anchor organelles
What are the 3 major types of cell junctions?
- tight junctions
- desmosomes
- gap junctions
What are the key features of tight junctions? (3)
- hold neighbouring cells tightly pressed together
- may form a continuous seal
- prevents fluid movement across cell layers
What are the key features of desmosomes? (3)
- anchoring junction
- provide attachment between sheets of cells
- connected into the cell by intermediate filaments
What are the key features of gap junctions? (3)
- point of cytoplasmic contact between two cells
- ions and small molecules can pass between cells
- allows rapid intercellular communication
what is ECM?
non-cellular component present within all tissues and organs
