Cels

• what is exocytosis (constitutive)?

  releases extracelluar matrix proteins
• what is exocytosis(regulated)? =

  releases hormones and neurotransmitters
• what is endocytosis( phagocytosis)?=

  non selective cell uptake of solid particles into food vacuole
• what is endocytosis(pinocytosis)?=

  non selective cell uptake of soutes within liquid via vesicle
• what is endocytosis(receptor-mediated)?=

  selectively uses receptors imbedded in the cell membrane to bind only to what is required by the cell.
• what is the function of a tight cell junction?

  prevents fluid moving between cell layers
• what is the function of a desmosome cell junction?

  anchors cells together
• what is the function of a gap junction?

  rapid cell communication and transport of ions and small molecules
• cytoskeleton=

  maintains cell shape

  keeps organelles in place

  rapidly disassembles and reassembles

  allows rapid changes in cell shape for cell division, etc

  dynamic—changes in cell shapes but still provide stability

  run in different directions to scaffold the shape
• microtubules

  the widest part of cytoskeleton

  made of proteins called tubulin

  resist compression

  fluid on the surface.

  paths for atp using motor proteins to carry vesicles throughout the cell.

  form cilia and flagella
• microfilaments

  twisted rope of actin

  resist tension- pulling forces-

  interacts with myosin for contraction
• intermediate filaments

  keratin proteins coiled together

  made of different proteins

  less dynamic

  form permanent cell structures.

  such as neurofilaments

  enables signals to travel smoothly
• integrins are inside the the cell membrane that connect the extracellular matrix to the cytoskeleton
• fibronectins attach cells to ecm
• Euchromatin

  less dense, contains genes being used by that cell

   
• Heterochromatin more dense, contains genes not being used by that cell